Merge branch 'main' into jetpack-custom-selector

app/build.gradle

@@ -100,12 +100,12 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-reflect:$KOTLIN_VERSION"
 
     //Mocking
-    testImplementation("io.mockk:mockk:1.13.4")
     testImplementation 'com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0'
     testImplementation 'org.mockito:mockito-inline:5.2.0'
     testImplementation 'org.mockito:mockito-core:5.6.0'
     testImplementation "org.powermock:powermock-module-junit4:2.0.9"
     testImplementation "org.powermock:powermock-api-mockito2:2.0.9"
+    testImplementation("io.mockk:mockk:1.13.5")
 
     // Unit testing
     testImplementation 'junit:junit:4.13.2'
@@ -374,11 +374,11 @@ android {
 
 
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_11
+        sourceCompatibility JavaVersion.VERSION_17
-        targetCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_17
     }
     kotlinOptions {
-        jvmTarget = "11"
+        jvmTarget = "17"
     }
 
     buildToolsVersion buildToolsVersion

app/src/main/java/fr/free/nrw/commons/LocationPicker/LocationPickerActivity.java

@@ -367,7 +367,7 @@ public class LocationPickerActivity extends BaseActivity implements
      */
     private void removeLocationFromImage() {
         if (media != null) {
-            compositeDisposable.add(coordinateEditHelper.makeCoordinatesEdit(getApplicationContext()
+            getCompositeDisposable().add(coordinateEditHelper.makeCoordinatesEdit(getApplicationContext()
                     , media, "0.0", "0.0", "0.0f")
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
@@ -479,7 +479,7 @@ public class LocationPickerActivity extends BaseActivity implements
         }
 
         try {
-            compositeDisposable.add(
+            getCompositeDisposable().add(
                 coordinateEditHelper.makeCoordinatesEdit(getApplicationContext(), media,
                         Latitude, Longitude, Accuracy)
                     .subscribeOn(Schedulers.io())

app/src/main/java/fr/free/nrw/commons/campaigns/CampaignView.java

@@ -12,15 +12,15 @@ import androidx.annotation.Nullable;
 import fr.free.nrw.commons.campaigns.models.Campaign;
 import fr.free.nrw.commons.databinding.LayoutCampaginBinding;
 import fr.free.nrw.commons.theme.BaseActivity;
-import fr.free.nrw.commons.utils.DateUtil;
+import fr.free.nrw.commons.utils.CommonsDateUtil;
 
+import fr.free.nrw.commons.utils.DateUtil;
 import java.text.ParseException;
 import java.util.Date;
 
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.Utils;
 import fr.free.nrw.commons.contributions.MainActivity;
-import fr.free.nrw.commons.utils.CommonsDateUtil;
 import fr.free.nrw.commons.utils.SwipableCardView;
 import fr.free.nrw.commons.utils.ViewUtil;
 

app/src/main/java/fr/free/nrw/commons/campaigns/CampaignsPresenter.java

@@ -3,6 +3,7 @@ package fr.free.nrw.commons.campaigns;
 import android.annotation.SuppressLint;
 
 import fr.free.nrw.commons.campaigns.models.Campaign;
+import fr.free.nrw.commons.utils.CommonsDateUtil;
 import java.text.ParseException;
 import java.util.Collections;
 import java.util.Date;
@@ -14,7 +15,6 @@ import javax.inject.Singleton;
 
 import fr.free.nrw.commons.BasePresenter;
 import fr.free.nrw.commons.mwapi.OkHttpJsonApiClient;
-import fr.free.nrw.commons.utils.CommonsDateUtil;
 import io.reactivex.Scheduler;
 import io.reactivex.Single;
 import io.reactivex.SingleObserver;

app/src/main/java/fr/free/nrw/commons/category/CategoryClient.kt

@@ -124,7 +124,9 @@ class CategoryClient
                 }.map {
                     it
                         .filter { page ->
-                            !page.categoryInfo().isHidden
+                            // Null check is not redundant because some values could be null
+                            // for mocks when running unit tests
+                            page.categoryInfo()?.isHidden != true
                         }.map {
                             CategoryItem(
                                 it.title().replace(CATEGORY_PREFIX, ""),

app/src/main/java/fr/free/nrw/commons/contributions/ContributionController.java

@@ -87,7 +87,7 @@ public class ContributionController {
             },
             R.string.storage_permission_title,
             R.string.write_storage_permission_rationale,
-            PermissionUtils.PERMISSIONS_STORAGE);
+            PermissionUtils.getPERMISSIONS_STORAGE());
     }
 
     /**
@@ -224,7 +224,7 @@ public class ContributionController {
             () -> FilePicker.openCustomSelector(activity, resultLauncher, 0),
             R.string.storage_permission_title,
             R.string.write_storage_permission_rationale,
-            PermissionUtils.PERMISSIONS_STORAGE);
+            PermissionUtils.getPERMISSIONS_STORAGE());
     }
 
 

app/src/main/java/fr/free/nrw/commons/contributions/ContributionsFragment.java

@@ -5,7 +5,6 @@ import static fr.free.nrw.commons.contributions.Contribution.STATE_FAILED;
 import static fr.free.nrw.commons.contributions.Contribution.STATE_PAUSED;
 import static fr.free.nrw.commons.nearby.fragments.NearbyParentFragment.WLM_URL;
 import static fr.free.nrw.commons.profile.ProfileActivity.KEY_USERNAME;
-import static fr.free.nrw.commons.utils.ImageUtils.IMAGE_OK;
 import static fr.free.nrw.commons.utils.LengthUtils.computeBearing;
 import static fr.free.nrw.commons.utils.LengthUtils.formatDistanceBetween;
 
@@ -23,12 +22,10 @@ import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
-import android.view.MenuItem.OnMenuItemClickListener;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.CheckBox;
 import android.widget.ImageView;
-import android.widget.LinearLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 import androidx.activity.result.ActivityResultCallback;
@@ -39,7 +36,6 @@ import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager.OnBackStackChangedListener;
 import androidx.fragment.app.FragmentTransaction;
-import fr.free.nrw.commons.CommonsApplication;
 import fr.free.nrw.commons.Utils;
 import fr.free.nrw.commons.auth.SessionManager;
 import fr.free.nrw.commons.databinding.FragmentContributionsBinding;
@@ -293,7 +289,7 @@ public class ContributionsFragment
             });
         }
         notification.setOnClickListener(view -> {
-            NotificationActivity.startYourself(getContext(), "unread");
+            NotificationActivity.Companion.startYourself(getContext(), "unread");
         });
     }
 

app/src/main/java/fr/free/nrw/commons/contributions/MainActivity.java

@@ -1,13 +1,10 @@
 package fr.free.nrw.commons.contributions;
 
-import android.Manifest.permission;
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
-import android.os.Build.VERSION;
-import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
@@ -16,10 +13,8 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
-import androidx.viewpager.widget.ViewPager;
 import androidx.work.ExistingWorkPolicy;
 import fr.free.nrw.commons.databinding.MainBinding;
-import fr.free.nrw.commons.CommonsApplication;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.WelcomeActivity;
 import fr.free.nrw.commons.auth.SessionManager;
@@ -41,7 +36,6 @@ import fr.free.nrw.commons.notification.NotificationController;
 import fr.free.nrw.commons.quiz.QuizChecker;
 import fr.free.nrw.commons.settings.SettingsFragment;
 import fr.free.nrw.commons.theme.BaseActivity;
-import fr.free.nrw.commons.upload.UploadActivity;
 import fr.free.nrw.commons.upload.UploadProgressActivity;
 import fr.free.nrw.commons.upload.worker.WorkRequestHelper;
 import fr.free.nrw.commons.utils.PermissionUtils;
@@ -420,7 +414,7 @@ public class MainActivity extends BaseActivity
                 return true;
             case R.id.notifications:
                 // Starts notification activity on click to notification icon
-                NotificationActivity.startYourself(this, "unread");
+                NotificationActivity.Companion.startYourself(this, "unread");
                 return true;
             default:
                 return super.onOptionsItemSelected(item);

app/src/main/java/fr/free/nrw/commons/customselector/helper/FolderDeletionHelper.kt

@@ -0,0 +1,249 @@
+package fr.free.nrw.commons.customselector.helper
+
+import android.content.ContentUris
+import android.content.Context
+import android.media.MediaScannerConnection
+import android.net.Uri
+import android.os.Build
+import android.provider.MediaStore
+import android.widget.Toast
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.IntentSenderRequest
+import androidx.appcompat.app.AlertDialog
+import fr.free.nrw.commons.R
+import timber.log.Timber
+import java.io.File
+
+object FolderDeletionHelper {
+
+    /**
+     * Prompts the user to confirm deletion of a specified folder and, if confirmed, deletes it.
+     *
+     * @param context The context used to show the confirmation dialog and manage deletion.
+     * @param folder The folder to be deleted.
+     * @param onDeletionComplete Callback invoked with `true` if the folder was
+     * @param trashFolderLauncher An ActivityResultLauncher for handling the result of the trash request.
+     * successfully deleted, `false` otherwise.
+     */
+    fun confirmAndDeleteFolder(
+        context: Context,
+        folder: File,
+        trashFolderLauncher: ActivityResultLauncher<IntentSenderRequest>,
+        onDeletionComplete: (Boolean) -> Unit) {
+        val itemCount = countItemsInFolder(context, folder)
+        val folderPath = folder.absolutePath
+
+        //don't show this dialog on API 30+, it's handled automatically using MediaStore
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            val success = deleteFolderMain(context, folder, trashFolderLauncher)
+            onDeletionComplete(success)
+
+        } else {
+            AlertDialog.Builder(context)
+                .setTitle(context.getString(R.string.custom_selector_confirm_deletion_title))
+                .setMessage(context.getString(R.string.custom_selector_confirm_deletion_message, folderPath, itemCount))
+                .setPositiveButton(context.getString(R.string.custom_selector_delete)) { _, _ ->
+
+                    //proceed with deletion if user confirms
+                    val success = deleteFolderMain(context, folder, trashFolderLauncher)
+                    onDeletionComplete(success)
+                }
+                .setNegativeButton(context.getString(R.string.custom_selector_cancel)) { dialog, _ ->
+                    dialog.dismiss()
+                    onDeletionComplete(false)
+                }
+                .show()
+        }
+    }
+
+    /**
+     * Deletes the specified folder, handling different Android storage models based on the API
+     *
+     * @param context The context used to manage storage operations.
+     * @param folder The folder to delete.
+     * @param trashFolderLauncher An ActivityResultLauncher for handling the result of the trash request.
+     * @return `true` if the folder deletion was successful, `false` otherwise.
+     */
+    private fun deleteFolderMain(
+        context: Context,
+        folder: File,
+        trashFolderLauncher: ActivityResultLauncher<IntentSenderRequest>): Boolean
+    {
+        return when {
+            //for API 30 and above, use MediaStore
+            Build.VERSION.SDK_INT >= Build.VERSION_CODES.R -> trashFolderContents(context, folder, trashFolderLauncher)
+
+            //for API 29 ('requestLegacyExternalStorage' is set to true in Manifest)
+            // and below use file system
+            else -> deleteFolderLegacy(folder)
+        }
+    }
+
+    /**
+     * Moves all contents of a specified folder to the trash on devices running
+     * Android 11 (API level 30) and above.
+     *
+     * @param context The context used to access the content resolver.
+     * @param folder The folder whose contents are to be moved to the trash.
+     * @param trashFolderLauncher An ActivityResultLauncher for handling the result of the trash request.
+     * @return `true` if the trash request was initiated successfully, `false` otherwise.
+     */
+    private fun trashFolderContents(
+        context: Context,
+        folder: File,
+        trashFolderLauncher: ActivityResultLauncher<IntentSenderRequest>): Boolean
+    {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) return false
+
+        val contentResolver = context.contentResolver
+        val folderPath = folder.absolutePath
+        val urisToTrash = mutableListOf<Uri>()
+
+        // Use URIs specific to media items
+        val mediaUris = listOf(
+            MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
+            MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
+            MediaStore.Audio.Media.EXTERNAL_CONTENT_URI
+        )
+
+        for (mediaUri in mediaUris) {
+            val selection = "${MediaStore.MediaColumns.DATA} LIKE ?"
+            val selectionArgs = arrayOf("$folderPath/%")
+
+            contentResolver.query(mediaUri, arrayOf(MediaStore.MediaColumns._ID), selection,
+                selectionArgs, null)
+                ?.use{ cursor ->
+                val idColumn = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns._ID)
+                while (cursor.moveToNext()) {
+                    val id = cursor.getLong(idColumn)
+                    val fileUri = ContentUris.withAppendedId(mediaUri, id)
+                    urisToTrash.add(fileUri)
+                }
+            }
+        }
+
+        //proceed with trashing if we have valid URIs
+        if (urisToTrash.isNotEmpty()) {
+            try {
+                val trashRequest = MediaStore.createTrashRequest(contentResolver, urisToTrash, true)
+                val intentSenderRequest = IntentSenderRequest.Builder(trashRequest.intentSender).build()
+                trashFolderLauncher.launch(intentSenderRequest)
+                return true
+            } catch (e: SecurityException) {
+                Timber.tag("DeleteFolder").e(context.getString(R.string.custom_selector_error_trashing_folder_contents, e.message))
+            }
+        }
+        return false
+    }
+
+
+    /**
+     * Counts the number of items in a specified folder, including items in subfolders.
+     *
+     * @param context The context used to access the content resolver.
+     * @param folder The folder in which to count items.
+     * @return The total number of items in the folder.
+     */
+    private fun countItemsInFolder(context: Context, folder: File): Int {
+        val contentResolver = context.contentResolver
+        val folderPath = folder.absolutePath
+        val uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
+        val selection = "${MediaStore.Images.Media.DATA} LIKE ?"
+        val selectionArgs = arrayOf("$folderPath/%")
+
+        return contentResolver.query(
+            uri,
+            arrayOf(MediaStore.Images.Media._ID),
+            selection,
+            selectionArgs,
+            null)?.use { cursor ->
+            cursor.count
+        } ?: 0
+    }
+
+
+
+    /**
+     * Refreshes the MediaStore for a specified folder, updating the system to recognize any changes
+     *
+     * @param context The context used to access the MediaScannerConnection.
+     * @param folder The folder to refresh in the MediaStore.
+     */
+    fun refreshMediaStore(context: Context, folder: File) {
+        MediaScannerConnection.scanFile(
+            context,
+            arrayOf(folder.absolutePath),
+            null
+        ) { _, _ -> }
+    }
+
+
+
+    /**
+     * Deletes a specified folder and all of its contents on devices running
+     * Android 10 (API level 29) and below.
+     *
+     * @param folder The `File` object representing the folder to be deleted.
+     * @return `true` if the folder and all contents were deleted successfully; `false` otherwise.
+     */
+    private fun deleteFolderLegacy(folder: File): Boolean {
+        return folder.deleteRecursively()
+    }
+
+
+    /**
+     * Retrieves the absolute path of a folder given its unique identifier (bucket ID).
+     *
+     * @param context The context used to access the content resolver.
+     * @param folderId The unique identifier (bucket ID) of the folder.
+     * @return The absolute path of the folder as a `String`, or `null` if the folder is not found.
+     */
+    fun getFolderPath(context: Context, folderId: Long): String? {
+        val projection = arrayOf(MediaStore.Images.Media.DATA)
+        val selection = "${MediaStore.Images.Media.BUCKET_ID} = ?"
+        val selectionArgs = arrayOf(folderId.toString())
+
+        context.contentResolver.query(
+            MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
+            projection,
+            selection,
+            selectionArgs,
+            null
+        )?.use { cursor ->
+            if (cursor.moveToFirst()) {
+                val fullPath = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA))
+                return File(fullPath).parent
+            }
+        }
+        return null
+    }
+
+    /**
+     * Displays an error message to the user and logs it for debugging purposes.
+     *
+     * @param context The context used to display the Toast.
+     * @param message The error message to display and log.
+     * @param folderName The name of the folder to delete.
+     */
+    fun showError(context: Context, message: String, folderName: String) {
+        Toast.makeText(context,
+            context.getString(R.string.custom_selector_folder_deleted_failure, folderName),
+            Toast.LENGTH_SHORT).show()
+        Timber.tag("DeleteFolder").e(message)
+    }
+
+    /**
+     * Displays a success message to the user.
+     *
+     * @param context The context used to display the Toast.
+     * @param message The success message to display.
+     * @param folderName The name of the folder to delete.
+     */
+    fun showSuccess(context: Context, message: String, folderName: String) {
+        Toast.makeText(context,
+            context.getString(R.string.custom_selector_folder_deleted_success, folderName),
+            Toast.LENGTH_SHORT).show()
+        Timber.tag("DeleteFolder").d(message)
+    }
+
+}

app/src/main/java/fr/free/nrw/commons/customselector/ui/selector/CustomSelectorActivity.kt

@@ -13,11 +13,26 @@ import android.view.View
 import android.view.Window
 import android.widget.Button
 import android.widget.ImageButton
+import android.widget.PopupMenu
 import android.widget.TextView
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.activity.result.ActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult
+import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedCard
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
@@ -34,6 +49,7 @@ import fr.free.nrw.commons.customselector.data.MediaReader
 import fr.free.nrw.commons.customselector.database.NotForUploadStatus
 import fr.free.nrw.commons.customselector.database.NotForUploadStatusDao
 import fr.free.nrw.commons.customselector.helper.CustomSelectorConstants
+import fr.free.nrw.commons.customselector.helper.FolderDeletionHelper
 import fr.free.nrw.commons.customselector.listeners.FolderClickListener
 import fr.free.nrw.commons.customselector.listeners.ImageSelectListener
 import fr.free.nrw.commons.customselector.model.Image
@@ -136,10 +152,23 @@ class CustomSelectorActivity :
 
     private var showPartialAccessIndicator by mutableStateOf(false)
 
-    private val startForResult = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){ result ->
+    /**
+     * Show delete button in folder
+     */
+    private var showOverflowMenu = false
+
+    /**
+     * Waits for confirmation of delete folder
+     */
+    private val startForFolderDeletionResult = registerForActivityResult(ActivityResultContracts.StartIntentSenderForResult()){
+        result -> onDeleteFolderResultReceived(result)
+    }
+
+    private val startForResult = registerForActivityResult(StartActivityForResult()){ result ->
         onFullScreenDataReceived(result)
     }
 
+
     /**
      * onCreate Activity, sets theme, initialises the view model, setup view.
      */
@@ -264,6 +293,15 @@ class CustomSelectorActivity :
         }
     }
 
+    private fun onDeleteFolderResultReceived(result: ActivityResult){
+        if (result.resultCode == Activity.RESULT_OK){
+            FolderDeletionHelper.showSuccess(this, "Folder deleted successfully", bucketName)
+            navigateToCustomSelector()
+        }
+    }
+
+
+
     /**
      * Show Custom Selector Welcome Dialog.
      */
@@ -445,10 +483,97 @@ class CustomSelectorActivity :
         val limitError: ImageButton = findViewById(R.id.image_limit_error)
         limitError.visibility = View.INVISIBLE
         limitError.setOnClickListener { displayUploadLimitWarning() }
+
+        val overflowMenu: ImageButton = findViewById(R.id.menu_overflow)
+        if(defaultKvStore.getBoolean("displayDeletionButton")) {
+            overflowMenu.visibility = if (showOverflowMenu) View.VISIBLE else View.INVISIBLE
+            overflowMenu.setOnClickListener { showPopupMenu(overflowMenu) }
+        }else{
+            overflowMenu.visibility = View.GONE
+        }
+
+    }
+
+    private fun showPopupMenu(anchorView: View) {
+        val popupMenu = PopupMenu(this, anchorView)
+        popupMenu.menuInflater.inflate(R.menu.menu_custom_selector, popupMenu.menu)
+
+        popupMenu.setOnMenuItemClickListener { item ->
+            when (item.itemId) {
+                R.id.action_delete_folder -> {
+                    deleteFolder()
+                    true
+                }
+                else -> false
+            }
+        }
+        popupMenu.show()
     }
 
     /**
-     * override on folder click, change the toolbar title on folder click.
+     * Deletes folder based on Android API version.
+     */
+    private fun deleteFolder() {
+        val folderPath = FolderDeletionHelper.getFolderPath(this, bucketId) ?: run {
+            FolderDeletionHelper.showError(this, "Failed to retrieve folder path", bucketName)
+            return
+        }
+
+        val folder = File(folderPath)
+        if (!folder.exists() || !folder.isDirectory) {
+            FolderDeletionHelper.showError(this,"Folder not found or is not a directory", bucketName)
+            return
+        }
+
+        FolderDeletionHelper.confirmAndDeleteFolder(this, folder, startForFolderDeletionResult) { success ->
+            if (success) {
+                //for API 30+, navigation is handled in 'onDeleteFolderResultReceived'
+                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
+                    FolderDeletionHelper.showSuccess(this, "Folder deleted successfully", bucketName)
+                    navigateToCustomSelector()
+                }
+            } else {
+                FolderDeletionHelper.showError(this, "Failed to delete folder", bucketName)
+            }
+        }
+    }
+
+
+
+    /**
+     * Navigates back to the main `FolderFragment`, refreshes the MediaStore, resets UI states,
+     * and reloads folder data.
+     */
+    private fun navigateToCustomSelector() {
+
+        val folderPath = FolderDeletionHelper.getFolderPath(this, bucketId) ?: ""
+        val folder = File(folderPath)
+
+        supportFragmentManager.popBackStack(null,
+                                androidx.fragment.app.FragmentManager.POP_BACK_STACK_INCLUSIVE)
+
+        //refresh MediaStore for the deleted folder path to ensure metadata updates
+        FolderDeletionHelper.refreshMediaStore(this, folder)
+
+        //replace the current fragment with FolderFragment to go back to the main screen
+        supportFragmentManager.beginTransaction()
+            .replace(R.id.fragment_container, FolderFragment.newInstance())
+            .commitAllowingStateLoss()
+
+        //reset toolbar and flags
+        isImageFragmentOpen = false
+        showOverflowMenu = false
+        setUpToolbar()
+        changeTitle(getString(R.string.custom_selector_title), 0)
+
+        //fetch updated folder data
+        fetchData()
+    }
+
+
+    /**
+     * override on folder click,
+     * change the toolbar title on folder click, make overflow menu visible
      */
     override fun onFolderClick(
         folderId: Long,
@@ -466,6 +591,11 @@ class CustomSelectorActivity :
         bucketId = folderId
         bucketName = folderName
         isImageFragmentOpen = true
+
+        //show the overflow menu only when a folder is clicked
+        showOverflowMenu = true
+        setUpToolbar()
+
     }
 
     /**
@@ -581,6 +711,10 @@ class CustomSelectorActivity :
             isImageFragmentOpen = false
             changeTitle(getString(R.string.custom_selector_title), 0)
         }
+
+        //hide overflow menu when not in folder
+        showOverflowMenu = false
+        setUpToolbar()
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/customselector/ui/selector/ImageFragment.kt

@@ -1,6 +1,7 @@
 package fr.free.nrw.commons.customselector.ui.selector
 
 import android.app.Activity
+import android.content.Context
 import android.content.Context.MODE_PRIVATE
 import android.content.SharedPreferences
 import android.os.Bundle
@@ -346,7 +347,7 @@ class ImageFragment :
                 context
                     .getSharedPreferences(
                         "CustomSelector",
-                        BaseActivity.MODE_PRIVATE,
+                        MODE_PRIVATE,
                     )?.let { prefs ->
                         prefs.edit()?.let { editor ->
                             editor.putLong("ItemId", imageAdapter.getImageIdAt(position))?.apply()

app/src/main/java/fr/free/nrw/commons/customselector/ui/selector/ImageLoader.kt

@@ -18,6 +18,7 @@ import fr.free.nrw.commons.utils.CustomSelectorUtils.Companion.checkWhetherFileE
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.MainScope
 import kotlinx.coroutines.launch
 import java.util.Calendar
 import java.util.concurrent.TimeUnit
@@ -65,7 +66,7 @@ class ImageLoader
         /**
          * Coroutine Scope.
          */
-        private val scope: CoroutineScope = CoroutineScope(Dispatchers.IO)
+        private val scope: CoroutineScope = MainScope()
 
         /**
          * Query image and setUp the view.

app/src/main/java/fr/free/nrw/commons/delete/DeleteHelper.java

@@ -1,10 +1,10 @@
 package fr.free.nrw.commons.delete;
 
 import static fr.free.nrw.commons.notification.NotificationHelper.NOTIFICATION_DELETE;
+import static fr.free.nrw.commons.utils.LangCodeUtils.getLocalizedResources;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
-import static fr.free.nrw.commons.utils.LangCodeUtils.getLocalizedResources;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.net.Uri;
@@ -16,6 +16,7 @@ import fr.free.nrw.commons.actions.PageEditClient;
 import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException;
 import fr.free.nrw.commons.notification.NotificationHelper;
 import fr.free.nrw.commons.review.ReviewController;
+import fr.free.nrw.commons.utils.LangCodeUtils;
 import fr.free.nrw.commons.utils.ViewUtilWrapper;
 import io.reactivex.Observable;
 import io.reactivex.Single;

app/src/main/java/fr/free/nrw/commons/delete/ReasonBuilder.java

@@ -3,7 +3,6 @@ package fr.free.nrw.commons.delete;
 import android.content.Context;
 
 import fr.free.nrw.commons.utils.DateUtil;
-
 import java.util.Date;
 import java.util.Locale;
 

app/src/main/java/fr/free/nrw/commons/di/CommonsApplicationComponent.java

@@ -2,7 +2,6 @@ package fr.free.nrw.commons.di;
 
 import com.google.gson.Gson;
 
-import fr.free.nrw.commons.actions.PageEditClient;
 import fr.free.nrw.commons.explore.categories.CategoriesModule;
 import fr.free.nrw.commons.navtab.MoreBottomSheetFragment;
 import fr.free.nrw.commons.navtab.MoreBottomSheetLoggedOutFragment;

app/src/main/java/fr/free/nrw/commons/explore/ExploreFragment.java

@@ -11,7 +11,6 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import androidx.viewpager.widget.ViewPager.OnPageChangeListener;
-import com.google.android.material.tabs.TabLayout;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.ViewPagerAdapter;
 import fr.free.nrw.commons.contributions.MainActivity;

app/src/main/java/fr/free/nrw/commons/explore/SearchActivity.java

@@ -104,7 +104,7 @@ public class SearchActivity extends BaseActivity
 
         viewPagerAdapter.setTabData(fragmentList, titleList);
         viewPagerAdapter.notifyDataSetChanged();
-        compositeDisposable.add(RxSearchView.queryTextChanges(binding.searchBox)
+        getCompositeDisposable().add(RxSearchView.queryTextChanges(binding.searchBox)
                 .takeUntil(RxView.detaches(binding.searchBox))
                 .debounce(500, TimeUnit.MILLISECONDS)
                 .observeOn(AndroidSchedulers.mainThread())
@@ -284,7 +284,7 @@ public class SearchActivity extends BaseActivity
     @Override protected void onDestroy() {
         super.onDestroy();
         //Dispose the disposables when the activity is destroyed
-        compositeDisposable.dispose();
+        getCompositeDisposable().dispose();
         binding = null;
     }
 }

app/src/main/java/fr/free/nrw/commons/explore/map/ExploreMapFragment.java

@@ -4,14 +4,12 @@ import static fr.free.nrw.commons.location.LocationServiceManager.LocationChange
 import static fr.free.nrw.commons.location.LocationServiceManager.LocationChangeType.LOCATION_SLIGHTLY_CHANGED;
 import static fr.free.nrw.commons.utils.MapUtils.ZOOM_LEVEL;
 
-import android.Manifest;
 import android.Manifest.permission;
 import android.annotation.SuppressLint;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
-import android.content.pm.PackageManager;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.graphics.Paint;
@@ -21,22 +19,17 @@ import android.location.Location;
 import android.location.LocationManager;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
-import android.provider.Settings;
 import android.text.Html;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
-import android.widget.Toast;
-import androidx.activity.result.ActivityResultCallback;
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.appcompat.widget.AppCompatTextView;
 import androidx.core.content.ContextCompat;
 import com.google.android.material.bottomsheet.BottomSheetBehavior;
-import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import com.google.android.material.snackbar.Snackbar;
 import fr.free.nrw.commons.BaseMarker;
 import fr.free.nrw.commons.MapController;
@@ -48,7 +41,6 @@ import fr.free.nrw.commons.databinding.FragmentExploreMapBinding;
 import fr.free.nrw.commons.di.CommonsDaggerSupportFragment;
 import fr.free.nrw.commons.explore.ExploreMapRootFragment;
 import fr.free.nrw.commons.explore.paging.LiveDataConverter;
-import fr.free.nrw.commons.filepicker.Constants;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
 import fr.free.nrw.commons.location.LatLng;
 import fr.free.nrw.commons.location.LocationPermissionsHelper;
@@ -60,7 +52,6 @@ import fr.free.nrw.commons.nearby.Place;
 import fr.free.nrw.commons.utils.DialogUtil;
 import fr.free.nrw.commons.utils.MapUtils;
 import fr.free.nrw.commons.utils.NetworkUtils;
-import fr.free.nrw.commons.utils.PermissionUtils;
 import fr.free.nrw.commons.utils.SystemThemeUtils;
 import fr.free.nrw.commons.utils.ViewUtil;
 import io.reactivex.Observable;
@@ -310,7 +301,7 @@ public class ExploreMapFragment extends CommonsDaggerSupportFragment
     }
 
     private void startMapWithoutPermission() {
-        lastKnownLocation = MapUtils.defaultLatLng;
+        lastKnownLocation = MapUtils.getDefaultLatLng();
         moveCameraToPosition(
             new GeoPoint(lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()));
         presenter.onMapReady(exploreMapController);
@@ -331,7 +322,7 @@ public class ExploreMapFragment extends CommonsDaggerSupportFragment
             !locationPermissionsHelper.checkLocationPermission(getActivity())) {
             isPermissionDenied = true;
         }
-        lastKnownLocation = MapUtils.defaultLatLng;
+        lastKnownLocation = MapUtils.getDefaultLatLng();
         moveCameraToPosition(
             new GeoPoint(lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()));
         presenter.onMapReady(exploreMapController);

app/src/main/java/fr/free/nrw/commons/filepicker/Constants.java

@@ -20,4 +20,4 @@ public interface Constants {
         String COPY_TAKEN_PHOTOS = "fr.free.nrw.commons.copy_taken_photos";
         String COPY_PICKED_IMAGES = "fr.free.nrw.commons.copy_picked_images";
     }
-}
+}

app/src/main/java/fr/free/nrw/commons/media/MediaDetailFragment.java

@@ -55,7 +55,6 @@ import fr.free.nrw.commons.Utils;
 import fr.free.nrw.commons.actions.ThanksClient;
 import fr.free.nrw.commons.auth.AccountUtil;
 import fr.free.nrw.commons.auth.SessionManager;
-import fr.free.nrw.commons.auth.csrf.CsrfTokenClient;
 import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException;
 import fr.free.nrw.commons.category.CategoryClient;
 import fr.free.nrw.commons.category.CategoryDetailsActivity;
@@ -272,6 +271,12 @@ public class MediaDetailFragment extends CommonsDaggerSupportFragment implements
 
         if (!sessionManager.isUserLoggedIn()) {
             binding.categoryEditButton.setVisibility(GONE);
+            binding.descriptionEdit.setVisibility(GONE);
+            binding.depictionsEditButton.setVisibility(GONE);
+        } else {
+            binding.categoryEditButton.setVisibility(VISIBLE);
+            binding.descriptionEdit.setVisibility(VISIBLE);
+            binding.depictionsEditButton.setVisibility(VISIBLE);
         }
 
         if(applicationKvStore.getBoolean("login_skipped")){
@@ -313,7 +318,7 @@ public class MediaDetailFragment extends CommonsDaggerSupportFragment implements
     }
 
     public void launchZoomActivity(final View view) {
-        final boolean hasPermission = PermissionUtils.hasPermission(getActivity(), PermissionUtils.PERMISSIONS_STORAGE);
+        final boolean hasPermission = PermissionUtils.hasPermission(getActivity(), PermissionUtils.getPERMISSIONS_STORAGE());
         if (hasPermission) {
             launchZoomActivityAfterPermissionCheck(view);
         } else {
@@ -323,7 +328,7 @@ public class MediaDetailFragment extends CommonsDaggerSupportFragment implements
                 },
                 R.string.storage_permission_title,
                 R.string.read_storage_permission_rationale,
-                PermissionUtils.PERMISSIONS_STORAGE
+                PermissionUtils.getPERMISSIONS_STORAGE()
                 );
         }
     }
@@ -400,7 +405,6 @@ public class MediaDetailFragment extends CommonsDaggerSupportFragment implements
             }
         );
         binding.progressBarEdit.setVisibility(GONE);
-        binding.descriptionEdit.setVisibility(VISIBLE);
     }
 
     @Override
@@ -678,7 +682,9 @@ public class MediaDetailFragment extends CommonsDaggerSupportFragment implements
             // Stick in a filler element.
             allCategories.add(getString(R.string.detail_panel_cats_none));
         }
-        binding.categoryEditButton.setVisibility(VISIBLE);
+        if(sessionManager.isUserLoggedIn()) {
+            binding.categoryEditButton.setVisibility(VISIBLE);
+        }
         rebuildCatList(allCategories);
     }
 

app/src/main/java/fr/free/nrw/commons/mwapi/OkHttpJsonApiClient.java

@@ -285,7 +285,7 @@ public class OkHttpJsonApiClient {
         throws Exception {
 
         Timber.d("Fetching nearby items at radius %s", radius);
-        Timber.d("CUSTOM_SPARQL%s", String.valueOf(customQuery != null));
+        Timber.d("CUSTOM_SPARQL: %s", String.valueOf(customQuery != null));
         final String wikidataQuery;
         if (customQuery != null) {
             wikidataQuery = customQuery;
@@ -344,7 +344,7 @@ public class OkHttpJsonApiClient {
         final boolean shouldQueryForMonuments, final String customQuery)
         throws Exception {
 
-        Timber.d("CUSTOM_SPARQL%s", String.valueOf(customQuery != null));
+        Timber.d("CUSTOM_SPARQL: %s", String.valueOf(customQuery != null));
 
         final String wikidataQuery;
         if (customQuery != null) {

app/src/main/java/fr/free/nrw/commons/navtab/MoreBottomSheetFragment.java

@@ -232,7 +232,7 @@ public class MoreBottomSheetFragment extends BottomSheetDialogFragment {
     }
 
     protected void onPeerReviewClicked() {
-        ReviewActivity.startYourself(getActivity(), getString(R.string.title_activity_review));
+        ReviewActivity.Companion.startYourself(getActivity(), getString(R.string.title_activity_review));
     }
 }
 

app/src/main/java/fr/free/nrw/commons/nearby/fragments/NearbyParentFragment.java

@@ -43,7 +43,6 @@ import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
 import android.view.animation.Animation;
 import android.view.animation.AnimationUtils;
-import android.widget.Button;
 import android.widget.Toast;
 import androidx.activity.result.ActivityResultCallback;
 import androidx.activity.result.ActivityResultLauncher;
@@ -701,7 +700,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
                 = new LatLng(Double.parseDouble(locationLatLng[0]),
                 Double.parseDouble(locationLatLng[1]), 1f);
         } else {
-            lastKnownLocation = MapUtils.defaultLatLng;
+            lastKnownLocation = MapUtils.getDefaultLatLng();
         }
         if (binding.map != null) {
             moveCameraToPosition(
@@ -793,7 +792,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
         hideBottomSheet();
         binding.nearbyFilter.searchViewLayout.searchView.setOnQueryTextFocusChangeListener(
             (v, hasFocus) -> {
-                LayoutUtils.setLayoutHeightAllignedToWidth(1.25,
+                LayoutUtils.setLayoutHeightAlignedToWidth(1.25,
                     binding.nearbyFilterList.getRoot());
                 if (hasFocus) {
                     binding.nearbyFilterList.getRoot().setVisibility(View.VISIBLE);
@@ -834,7 +833,7 @@ public class NearbyParentFragment extends CommonsDaggerSupportFragment
             .getLayoutParams().width = (int) LayoutUtils.getScreenWidth(getActivity(),
             0.75);
         binding.nearbyFilterList.searchListView.setAdapter(nearbyFilterSearchRecyclerViewAdapter);
-        LayoutUtils.setLayoutHeightAllignedToWidth(1.25, binding.nearbyFilterList.getRoot());
+        LayoutUtils.setLayoutHeightAlignedToWidth(1.25, binding.nearbyFilterList.getRoot());
         compositeDisposable.add(
             RxSearchView.queryTextChanges(binding.nearbyFilter.searchViewLayout.searchView)
                 .takeUntil(RxView.detaches(binding.nearbyFilter.searchViewLayout.searchView))

app/src/main/java/fr/free/nrw/commons/nearby/presenter/NearbyParentFragmentPresenter.java

@@ -11,13 +11,10 @@ import static fr.free.nrw.commons.nearby.CheckBoxTriStates.UNKNOWN;
 import static fr.free.nrw.commons.wikidata.WikidataConstants.PLACE_OBJECT;
 
 import android.location.Location;
-import android.view.View;
 import androidx.annotation.MainThread;
 import androidx.annotation.Nullable;
-import androidx.work.ExistingWorkPolicy;
 import fr.free.nrw.commons.BaseMarker;
 import fr.free.nrw.commons.bookmarks.locations.BookmarkLocationsDao;
-import fr.free.nrw.commons.contributions.Contribution;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
 import fr.free.nrw.commons.location.LatLng;
 import fr.free.nrw.commons.location.LocationServiceManager.LocationChangeType;
@@ -26,14 +23,10 @@ import fr.free.nrw.commons.nearby.CheckBoxTriStates;
 import fr.free.nrw.commons.nearby.Label;
 import fr.free.nrw.commons.nearby.MarkerPlaceGroup;
 import fr.free.nrw.commons.nearby.NearbyController;
-import fr.free.nrw.commons.nearby.NearbyFilterState;
 import fr.free.nrw.commons.nearby.Place;
-import fr.free.nrw.commons.nearby.PlaceDao;
 import fr.free.nrw.commons.nearby.contract.NearbyParentFragmentContract;
-import fr.free.nrw.commons.upload.worker.WorkRequestHelper;
 import fr.free.nrw.commons.utils.LocationUtils;
 import fr.free.nrw.commons.wikidata.WikidataEditListener;
-import io.reactivex.disposables.CompositeDisposable;
 import java.lang.reflect.Proxy;
 import java.util.List;
 import timber.log.Timber;

app/src/main/java/fr/free/nrw/commons/notification/NotificationActivity.java

@@ -1,288 +0,0 @@
-package fr.free.nrw.commons.notification;
-
-import android.annotation.SuppressLint;
-import android.content.Context;
-import android.content.Intent;
-import android.net.Uri;
-import android.os.Bundle;
-import android.view.Menu;
-import android.view.MenuInflater;
-import android.view.MenuItem;
-import android.view.View;
-import androidx.recyclerview.widget.DividerItemDecoration;
-import androidx.recyclerview.widget.LinearLayoutManager;
-import com.google.android.material.snackbar.Snackbar;
-import fr.free.nrw.commons.CommonsApplication;
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.Utils;
-import fr.free.nrw.commons.databinding.ActivityNotificationBinding;
-import fr.free.nrw.commons.auth.SessionManager;
-import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException;
-import fr.free.nrw.commons.notification.models.Notification;
-import fr.free.nrw.commons.notification.models.NotificationType;
-import fr.free.nrw.commons.theme.BaseActivity;
-import fr.free.nrw.commons.utils.NetworkUtils;
-import fr.free.nrw.commons.utils.ViewUtil;
-import io.reactivex.Observable;
-import io.reactivex.ObservableSource;
-import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.disposables.Disposable;
-import io.reactivex.schedulers.Schedulers;
-import java.util.Collections;
-import java.util.List;
-import java.util.concurrent.Callable;
-import javax.inject.Inject;
-import kotlin.Unit;
-import timber.log.Timber;
-
-/**
- * Created by root on 18.12.2017.
- */
-
-public class NotificationActivity extends BaseActivity {
-    private ActivityNotificationBinding binding;
-
-    @Inject
-    NotificationController controller;
-
-    @Inject
-    SessionManager sessionManager;
-
-    private static final String TAG_NOTIFICATION_WORKER_FRAGMENT = "NotificationWorkerFragment";
-    private NotificationWorkerFragment mNotificationWorkerFragment;
-    private NotificatinAdapter adapter;
-    private List<Notification> notificationList;
-    MenuItem notificationMenuItem;
-    /**
-     * Boolean isRead is true if this notification activity is for read section of notification.
-     */
-    private boolean isRead;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        isRead = getIntent().getStringExtra("title").equals("read");
-        binding = ActivityNotificationBinding.inflate(getLayoutInflater());
-        setContentView(binding.getRoot());
-        mNotificationWorkerFragment = (NotificationWorkerFragment) getFragmentManager()
-                .findFragmentByTag(TAG_NOTIFICATION_WORKER_FRAGMENT);
-        initListView();
-        setPageTitle();
-        setSupportActionBar(binding.toolbar.toolbar);
-        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-    }
-
-    @Override
-    public boolean onSupportNavigateUp() {
-        onBackPressed();
-        return true;
-    }
-
-    /**
-     * If this is unread section of the notifications, removeNotification method
-     *  Marks the notification as read,
-     *  Removes the notification from unread,
-     *  Displays the Snackbar.
-     *
-     * Otherwise returns (read section).
-     *
-     * @param notification
-     */
-    @SuppressLint("CheckResult")
-    public void removeNotification(Notification notification) {
-        if (isRead) {
-            return;
-        }
-        Disposable disposable = Observable.defer((Callable<ObservableSource<Boolean>>)
-                () -> controller.markAsRead(notification))
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(result -> {
-                    if (result) {
-                        notificationList.remove(notification);
-                        setItems(notificationList);
-                        adapter.notifyDataSetChanged();
-                        ViewUtil.showLongSnackbar(binding.container,getString(R.string.notification_mark_read));
-                        if (notificationList.size() == 0) {
-                            setEmptyView();
-                            binding.container.setVisibility(View.GONE);
-                            binding.noNotificationBackground.setVisibility(View.VISIBLE);
-                        }
-                    } else {
-                        adapter.notifyDataSetChanged();
-                        setItems(notificationList);
-                        ViewUtil.showLongToast(this,getString(R.string.some_error));
-                    }
-                }, throwable -> {
-                    if (throwable instanceof InvalidLoginTokenException) {
-                        final String username = sessionManager.getUserName();
-                        final CommonsApplication.BaseLogoutListener logoutListener = new CommonsApplication.BaseLogoutListener(
-                            this,
-                            getString(R.string.invalid_login_message),
-                            username
-                        );
-
-                        CommonsApplication.getInstance().clearApplicationData(
-                            this, logoutListener);
-                    } else {
-                        Timber.e(throwable, "Error occurred while loading notifications");
-                        throwable.printStackTrace();
-                    ViewUtil.showShortSnackbar(binding.container, R.string.error_notifications);
-                    binding.progressBar.setVisibility(View.GONE);
-                        ViewUtil.showShortSnackbar(binding.container, R.string.error_notifications);
-                    }
-                    binding.progressBar.setVisibility(View.GONE);
-                });
-        compositeDisposable.add(disposable);
-    }
-
-
-
-    private void initListView() {
-        binding.listView.setLayoutManager(new LinearLayoutManager(this));
-        DividerItemDecoration itemDecor = new DividerItemDecoration(binding.listView.getContext(), DividerItemDecoration.VERTICAL);
-        binding.listView.addItemDecoration(itemDecor);
-        if (isRead) {
-            refresh(true);
-        } else {
-            refresh(false);
-        }
-        adapter = new NotificatinAdapter(item -> {
-            Timber.d("Notification clicked %s", item.getLink());
-            if (item.getNotificationType() == NotificationType.EMAIL){
-                ViewUtil.showLongSnackbar(binding.container,getString(R.string.check_your_email_inbox));
-            } else {
-                handleUrl(item.getLink());
-            }
-            removeNotification(item);
-            return Unit.INSTANCE;
-        });
-        binding.listView.setAdapter(adapter);
-    }
-
-    private void refresh(boolean archived) {
-        if (!NetworkUtils.isInternetConnectionEstablished(this)) {
-            binding.progressBar.setVisibility(View.GONE);
-            Snackbar.make(binding.container, R.string.no_internet, Snackbar.LENGTH_INDEFINITE)
-                    .setAction(R.string.retry, view -> refresh(archived)).show();
-        } else {
-            addNotifications(archived);
-        }
-        binding.progressBar.setVisibility(View.VISIBLE);
-        binding.noNotificationBackground.setVisibility(View.GONE);
-        binding.container.setVisibility(View.VISIBLE);
-    }
-
-    @SuppressLint("CheckResult")
-    private void addNotifications(boolean archived) {
-        Timber.d("Add notifications");
-        if (mNotificationWorkerFragment == null) {
-            binding.progressBar.setVisibility(View.VISIBLE);
-            compositeDisposable.add(controller.getNotifications(archived)
-                    .subscribeOn(Schedulers.io())
-                    .observeOn(AndroidSchedulers.mainThread())
-                    .subscribe(notificationList -> {
-                        Collections.reverse(notificationList);
-                        Timber.d("Number of notifications is %d", notificationList.size());
-                        this.notificationList = notificationList;
-                        if (notificationList.size()==0){
-                            setEmptyView();
-                            binding.container.setVisibility(View.GONE);
-                            binding.noNotificationBackground.setVisibility(View.VISIBLE);
-                        } else {
-                            setItems(notificationList);
-                        }
-                        binding.progressBar.setVisibility(View.GONE);
-                    }, throwable -> {
-                        Timber.e(throwable, "Error occurred while loading notifications ");
-                        ViewUtil.showShortSnackbar(binding.container, R.string.error_notifications);
-                        binding.progressBar.setVisibility(View.GONE);
-                    }));
-        } else {
-            notificationList = mNotificationWorkerFragment.getNotificationList();
-            setItems(notificationList);
-        }
-    }
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        MenuInflater inflater = getMenuInflater();
-        inflater.inflate(R.menu.menu_notifications, menu);
-        notificationMenuItem = menu.findItem(R.id.archived);
-        setMenuItemTitle();
-        return true;
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        // Handle item selection
-        switch (item.getItemId()) {
-            case R.id.archived:
-                if (item.getTitle().equals(getString(R.string.menu_option_read))) {
-                    NotificationActivity.startYourself(NotificationActivity.this, "read");
-                }else if (item.getTitle().equals(getString(R.string.menu_option_unread))) {
-                    onBackPressed();
-                }
-                return true;
-            default:
-                return super.onOptionsItemSelected(item);
-        }
-    }
-
-    private void handleUrl(String url) {
-        if (url == null || url.equals("")) {
-            return;
-        }
-        Utils.handleWebUrl(this, Uri.parse(url));
-    }
-
-    private void setItems(List<Notification> notificationList) {
-        if (notificationList == null || notificationList.isEmpty()) {
-            ViewUtil.showShortSnackbar(binding.container, R.string.no_notifications);
-            /*progressBar.setVisibility(View.GONE);
-            recyclerView.setVisibility(View.GONE);*/
-            binding.container.setVisibility(View.GONE);
-            setEmptyView();
-            binding.noNotificationBackground.setVisibility(View.VISIBLE);
-            return;
-        }
-        binding.container.setVisibility(View.VISIBLE);
-        binding.noNotificationBackground.setVisibility(View.GONE);
-        adapter.setItems(notificationList);
-    }
-
-    public static void startYourself(Context context, String title) {
-        Intent intent = new Intent(context, NotificationActivity.class);
-        intent.putExtra("title", title);
-
-        context.startActivity(intent);
-    }
-
-    private void setPageTitle() {
-        if (getSupportActionBar() != null) {
-            if (isRead) {
-                getSupportActionBar().setTitle(R.string.read_notifications);
-            } else {
-                getSupportActionBar().setTitle(R.string.notifications);
-            }
-        }
-    }
-
-    private void setEmptyView() {
-        if (isRead) {
-            binding.noNotificationText.setText(R.string.no_read_notification);
-        }else {
-            binding.noNotificationText.setText(R.string.no_notification);
-        }
-    }
-
-    private void setMenuItemTitle() {
-        if (isRead) {
-            notificationMenuItem.setTitle(R.string.menu_option_unread);
-
-        }else {
-            notificationMenuItem.setTitle(R.string.menu_option_read);
-
-        }
-    }
-}

app/src/main/java/fr/free/nrw/commons/notification/NotificationActivity.kt

@@ -0,0 +1,247 @@
+package fr.free.nrw.commons.notification
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
+import android.view.Menu
+import android.view.MenuItem
+import android.view.View
+import androidx.recyclerview.widget.DividerItemDecoration
+import androidx.recyclerview.widget.LinearLayoutManager
+import com.google.android.material.snackbar.Snackbar
+import fr.free.nrw.commons.CommonsApplication
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.Utils
+import fr.free.nrw.commons.auth.SessionManager
+import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException
+import fr.free.nrw.commons.databinding.ActivityNotificationBinding
+import fr.free.nrw.commons.notification.models.Notification
+import fr.free.nrw.commons.notification.models.NotificationType
+import fr.free.nrw.commons.theme.BaseActivity
+import fr.free.nrw.commons.utils.NetworkUtils
+import fr.free.nrw.commons.utils.ViewUtil
+import io.reactivex.Observable
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.schedulers.Schedulers
+import timber.log.Timber
+import javax.inject.Inject
+
+/**
+ * Created by root on 18.12.2017.
+ */
+class NotificationActivity : BaseActivity() {
+
+    private lateinit var binding: ActivityNotificationBinding
+
+    @Inject
+    lateinit var controller: NotificationController
+
+    @Inject
+    lateinit var sessionManager: SessionManager
+
+    private val tagNotificationWorkerFragment = "NotificationWorkerFragment"
+    private var mNotificationWorkerFragment: NotificationWorkerFragment? = null
+    private lateinit var adapter: NotificationAdapter
+    private var notificationList: MutableList<Notification> = mutableListOf()
+    private var notificationMenuItem: MenuItem? = null
+
+    /**
+     * Boolean isRead is true if this notification activity is for read section of notification.
+     */
+    private var isRead: Boolean = false
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        isRead = intent.getStringExtra("title") == "read"
+        binding = ActivityNotificationBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+        mNotificationWorkerFragment = supportFragmentManager.findFragmentByTag(
+            tagNotificationWorkerFragment
+        ) as? NotificationWorkerFragment
+        initListView()
+        setPageTitle()
+        setSupportActionBar(binding.toolbar.toolbar)
+        supportActionBar?.setDisplayHomeAsUpEnabled(true)
+    }
+
+    override fun onSupportNavigateUp(): Boolean {
+        onBackPressed()
+        return true
+    }
+
+    @SuppressLint("CheckResult", "NotifyDataSetChanged")
+    fun removeNotification(notification: Notification) {
+        if (isRead) return
+
+        val disposable = Observable.defer { controller.markAsRead(notification) }
+            .subscribeOn(Schedulers.io())
+            .observeOn(AndroidSchedulers.mainThread())
+            .subscribe({ result ->
+                if (result) {
+                    notificationList.remove(notification)
+                    setItems(notificationList)
+                    adapter.notifyDataSetChanged()
+                    ViewUtil.showLongSnackbar(binding.container, getString(R.string.notification_mark_read))
+                    if (notificationList.isEmpty()) {
+                        setEmptyView()
+                        binding.container.visibility = View.GONE
+                        binding.noNotificationBackground.visibility = View.VISIBLE
+                    }
+                } else {
+                    adapter.notifyDataSetChanged()
+                    setItems(notificationList)
+                    ViewUtil.showLongToast(this, getString(R.string.some_error))
+                }
+            }, { throwable ->
+                if (throwable is InvalidLoginTokenException) {
+                    val username = sessionManager.getUserName()
+                    val logoutListener = CommonsApplication.BaseLogoutListener(
+                        this,
+                        getString(R.string.invalid_login_message),
+                        username
+                    )
+                    CommonsApplication.instance.clearApplicationData(this, logoutListener)
+                } else {
+                    Timber.e(throwable, "Error occurred while loading notifications")
+                    ViewUtil.showShortSnackbar(binding.container, R.string.error_notifications)
+                }
+                binding.progressBar.visibility = View.GONE
+            })
+        compositeDisposable.add(disposable)
+    }
+
+    private fun initListView() {
+        binding.listView.layoutManager = LinearLayoutManager(this)
+        val itemDecor = DividerItemDecoration(binding.listView.context, DividerItemDecoration.VERTICAL)
+        binding.listView.addItemDecoration(itemDecor)
+        refresh(isRead)
+        adapter = NotificationAdapter { item ->
+            Timber.d("Notification clicked %s", item.link)
+            if (item.notificationType == NotificationType.EMAIL) {
+                ViewUtil.showLongSnackbar(binding.container, getString(R.string.check_your_email_inbox))
+            } else {
+                handleUrl(item.link)
+            }
+            removeNotification(item)
+        }
+        binding.listView.adapter = adapter
+    }
+
+    private fun refresh(archived: Boolean) {
+        if (!NetworkUtils.isInternetConnectionEstablished(this)) {
+            binding.progressBar.visibility = View.GONE
+            Snackbar.make(binding.container, R.string.no_internet, Snackbar.LENGTH_INDEFINITE)
+                .setAction(R.string.retry) { refresh(archived) }
+                .show()
+        } else {
+            addNotifications(archived)
+        }
+        binding.progressBar.visibility = View.VISIBLE
+        binding.noNotificationBackground.visibility = View.GONE
+        binding.container.visibility = View.VISIBLE
+    }
+
+    @SuppressLint("CheckResult")
+    private fun addNotifications(archived: Boolean) {
+        Timber.d("Add notifications")
+        if (mNotificationWorkerFragment == null) {
+            binding.progressBar.visibility = View.VISIBLE
+            compositeDisposable.add(controller.getNotifications(archived)
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe({ notificationList ->
+                    notificationList.reversed()
+                    Timber.d("Number of notifications is %d", notificationList.size)
+                    this.notificationList = notificationList.toMutableList()
+                    if (notificationList.isEmpty()) {
+                        setEmptyView()
+                        binding.container.visibility = View.GONE
+                        binding.noNotificationBackground.visibility = View.VISIBLE
+                    } else {
+                        setItems(notificationList)
+                    }
+                    binding.progressBar.visibility = View.GONE
+                }, { throwable ->
+                    Timber.e(throwable, "Error occurred while loading notifications")
+                    ViewUtil.showShortSnackbar(binding.container, R.string.error_notifications)
+                    binding.progressBar.visibility = View.GONE
+                }))
+        } else {
+            notificationList = mNotificationWorkerFragment?.notificationList?.toMutableList() ?: mutableListOf()
+            setItems(notificationList)
+        }
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        menuInflater.inflate(R.menu.menu_notifications, menu)
+        notificationMenuItem = menu.findItem(R.id.archived)
+        setMenuItemTitle()
+        return true
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        return when (item.itemId) {
+            R.id.archived -> {
+                if (item.title == getString(R.string.menu_option_read)) {
+                    startYourself(this, "read")
+                } else if (item.title == getString(R.string.menu_option_unread)) {
+                    onBackPressed()
+                }
+                true
+            }
+            else -> super.onOptionsItemSelected(item)
+        }
+    }
+
+    private fun handleUrl(url: String?) {
+        if (url.isNullOrEmpty()) return
+        Utils.handleWebUrl(this, Uri.parse(url))
+    }
+
+    private fun setItems(notificationList: List<Notification>?) {
+        if (notificationList.isNullOrEmpty()) {
+            ViewUtil.showShortSnackbar(binding.container, R.string.no_notifications)
+            binding.container.visibility = View.GONE
+            setEmptyView()
+            binding.noNotificationBackground.visibility = View.VISIBLE
+            return
+        }
+        binding.container.visibility = View.VISIBLE
+        binding.noNotificationBackground.visibility = View.GONE
+        adapter.items = notificationList
+    }
+
+    private fun setPageTitle() {
+        supportActionBar?.title = if (isRead) {
+            getString(R.string.read_notifications)
+        } else {
+            getString(R.string.notifications)
+        }
+    }
+
+    private fun setEmptyView() {
+        binding.noNotificationText.text = if (isRead) {
+            getString(R.string.no_read_notification)
+        } else {
+            getString(R.string.no_notification)
+        }
+    }
+
+    private fun setMenuItemTitle() {
+        notificationMenuItem?.title = if (isRead) {
+            getString(R.string.menu_option_unread)
+        } else {
+            getString(R.string.menu_option_read)
+        }
+    }
+
+    companion object {
+        fun startYourself(context: Context, title: String) {
+            val intent = Intent(context, NotificationActivity::class.java)
+            intent.putExtra("title", title)
+            context.startActivity(intent)
+        }
+    }
+}

app/src/main/java/fr/free/nrw/commons/notification/NotificationAdapter.kt

@@ -3,7 +3,7 @@ package fr.free.nrw.commons.notification
 import fr.free.nrw.commons.notification.models.Notification
 import fr.free.nrw.commons.upload.categories.BaseDelegateAdapter
 
-internal class NotificatinAdapter(
+internal class NotificationAdapter(
     onNotificationClicked: (Notification) -> Unit,
 ) : BaseDelegateAdapter<Notification>(
         notificationDelegate(onNotificationClicked),

app/src/main/java/fr/free/nrw/commons/notification/NotificationController.java

@@ -1,33 +0,0 @@
-package fr.free.nrw.commons.notification;
-
-import fr.free.nrw.commons.notification.models.Notification;
-import java.util.List;
-
-import javax.inject.Inject;
-import javax.inject.Singleton;
-
-import io.reactivex.Observable;
-import io.reactivex.Single;
-
-/**
- * Created by root on 19.12.2017.
- */
-@Singleton
-public class NotificationController {
-
-    private NotificationClient notificationClient;
-
-
-    @Inject
-    public NotificationController(NotificationClient notificationClient) {
-        this.notificationClient = notificationClient;
-    }
-
-    public Single<List<Notification>> getNotifications(boolean archived) {
-        return notificationClient.getNotifications(archived);
-    }
-
-    Observable<Boolean> markAsRead(Notification notification) {
-        return notificationClient.markNotificationAsRead(notification.getNotificationId());
-    }
-}

app/src/main/java/fr/free/nrw/commons/notification/NotificationController.kt

@@ -0,0 +1,25 @@
+package fr.free.nrw.commons.notification
+
+import fr.free.nrw.commons.notification.models.Notification
+import javax.inject.Inject
+import javax.inject.Singleton
+
+import io.reactivex.Observable
+import io.reactivex.Single
+
+/**
+ * Created by root on 19.12.2017.
+ */
+@Singleton
+class NotificationController @Inject constructor(
+    private val notificationClient: NotificationClient
+) {
+
+    fun getNotifications(archived: Boolean): Single<List<Notification>> {
+        return notificationClient.getNotifications(archived)
+    }
+
+    fun markAsRead(notification: Notification): Observable<Boolean> {
+        return notificationClient.markNotificationAsRead(notification.notificationId)
+    }
+}

app/src/main/java/fr/free/nrw/commons/notification/NotificationHelper.java

@@ -1,73 +0,0 @@
-package fr.free.nrw.commons.notification;
-
-import android.app.NotificationManager;
-import android.app.PendingIntent;
-import android.content.Context;
-import android.content.Intent;
-import android.os.Build;
-import androidx.core.app.NotificationCompat;
-import javax.inject.Inject;
-import javax.inject.Singleton;
-import fr.free.nrw.commons.CommonsApplication;
-import fr.free.nrw.commons.R;
-import static androidx.core.app.NotificationCompat.DEFAULT_ALL;
-import static androidx.core.app.NotificationCompat.PRIORITY_HIGH;
-
-/**
- * Helper class that can be used to build a generic notification
- * Going forward all notifications should be built using this helper class
- */
-@Singleton
-public class NotificationHelper {
-
-    public static final int NOTIFICATION_DELETE = 1;
-    public static final int NOTIFICATION_EDIT_CATEGORY = 2;
-    public static final int NOTIFICATION_EDIT_COORDINATES = 3;
-    public static final int NOTIFICATION_EDIT_DESCRIPTION = 4;
-    public static final int NOTIFICATION_EDIT_DEPICTIONS = 5;
-
-    private final NotificationManager notificationManager;
-    private final NotificationCompat.Builder notificationBuilder;
-
-    @Inject
-    public NotificationHelper(final Context context) {
-        notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
-        notificationBuilder = new NotificationCompat
-                .Builder(context, CommonsApplication.NOTIFICATION_CHANNEL_ID_ALL)
-                .setOnlyAlertOnce(true);
-    }
-
-    /**
-     * Public interface to build and show a notification in the notification bar
-     * @param context passed context
-     * @param notificationTitle title of the notification
-     * @param notificationMessage message to be displayed in the notification
-     * @param notificationId the notificationID
-     * @param intent the intent to be fired when the notification is clicked
-     */
-    public void showNotification(
-        final Context context,
-        final String notificationTitle,
-        final String notificationMessage,
-        final int notificationId,
-        final Intent intent
-    ) {
-        notificationBuilder.setDefaults(DEFAULT_ALL)
-            .setContentTitle(notificationTitle)
-            .setStyle(new NotificationCompat.BigTextStyle()
-                .bigText(notificationMessage))
-            .setSmallIcon(R.drawable.ic_launcher)
-            .setProgress(0, 0, false)
-            .setOngoing(false)
-            .setPriority(PRIORITY_HIGH);
-
-        int flags = PendingIntent.FLAG_UPDATE_CURRENT;
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-            flags |= PendingIntent.FLAG_IMMUTABLE; // This flag was introduced in API 23
-        }
-
-        final PendingIntent pendingIntent = PendingIntent.getActivity(context, 1, intent, flags);
-        notificationBuilder.setContentIntent(pendingIntent);
-        notificationManager.notify(notificationId, notificationBuilder.build());
-    }
-}

app/src/main/java/fr/free/nrw/commons/notification/NotificationHelper.kt

@@ -0,0 +1,73 @@
+package fr.free.nrw.commons.notification
+
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import androidx.core.app.NotificationCompat
+import javax.inject.Inject
+import javax.inject.Singleton
+import fr.free.nrw.commons.CommonsApplication
+import fr.free.nrw.commons.R
+import androidx.core.app.NotificationCompat.DEFAULT_ALL
+import androidx.core.app.NotificationCompat.PRIORITY_HIGH
+
+/**
+ * Helper class that can be used to build a generic notification
+ * Going forward all notifications should be built using this helper class
+ */
+@Singleton
+class NotificationHelper @Inject constructor(
+    context: Context
+) {
+
+    companion object {
+        const val NOTIFICATION_DELETE = 1
+        const val NOTIFICATION_EDIT_CATEGORY = 2
+        const val NOTIFICATION_EDIT_COORDINATES = 3
+        const val NOTIFICATION_EDIT_DESCRIPTION = 4
+        const val NOTIFICATION_EDIT_DEPICTIONS = 5
+    }
+
+    private val notificationManager: NotificationManager =
+        context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+
+    private val notificationBuilder: NotificationCompat.Builder = NotificationCompat
+        .Builder(context, CommonsApplication.NOTIFICATION_CHANNEL_ID_ALL)
+        .setOnlyAlertOnce(true)
+
+    /**
+     * Public interface to build and show a notification in the notification bar
+     * @param context passed context
+     * @param notificationTitle title of the notification
+     * @param notificationMessage message to be displayed in the notification
+     * @param notificationId the notificationID
+     * @param intent the intent to be fired when the notification is clicked
+     */
+    fun showNotification(
+        context: Context,
+        notificationTitle: String,
+        notificationMessage: String,
+        notificationId: Int,
+        intent: Intent
+    ) {
+        notificationBuilder.setDefaults(NotificationCompat.DEFAULT_ALL)
+            .setContentTitle(notificationTitle)
+            .setStyle(NotificationCompat.BigTextStyle().bigText(notificationMessage))
+            .setSmallIcon(R.drawable.ic_launcher)
+            .setProgress(0, 0, false)
+            .setOngoing(false)
+            .setPriority(NotificationCompat.PRIORITY_HIGH)
+
+        val flags = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+        } else {
+            PendingIntent.FLAG_UPDATE_CURRENT
+        }
+
+        val pendingIntent = PendingIntent.getActivity(context, 1, intent, flags)
+        notificationBuilder.setContentIntent(pendingIntent)
+        notificationManager.notify(notificationId, notificationBuilder.build())
+    }
+}

app/src/main/java/fr/free/nrw/commons/notification/NotificationWorkerFragment.java

@@ -1,31 +0,0 @@
-package fr.free.nrw.commons.notification;
-
-import android.app.Fragment;
-import android.os.Bundle;
-
-import androidx.annotation.Nullable;
-
-import fr.free.nrw.commons.notification.models.Notification;
-import java.util.List;
-
-/**
- * Created by knightshade on 25/2/18.
- */
-
-public class NotificationWorkerFragment extends Fragment {
-    private List<Notification> notificationList;
-
-    @Override
-    public void onCreate(@Nullable Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setRetainInstance(true);
-    }
-
-    public void setNotificationList(List<Notification> notificationList){
-        this.notificationList = notificationList;
-    }
-
-    public List<Notification> getNotificationList(){
-        return notificationList;
-    }
-}

app/src/main/java/fr/free/nrw/commons/notification/NotificationWorkerFragment.kt

@@ -0,0 +1,20 @@
+package fr.free.nrw.commons.notification
+
+import android.app.Fragment
+import android.os.Bundle
+
+import fr.free.nrw.commons.notification.models.Notification
+
+
+/**
+ * Created by knightshade on 25/2/18.
+ */
+class NotificationWorkerFragment : Fragment() {
+
+    var notificationList: List<Notification>? = null
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        retainInstance = true
+    }
+}

app/src/main/java/fr/free/nrw/commons/notification/models/NotificationType.java

@@ -1,28 +0,0 @@
-package fr.free.nrw.commons.notification.models;
-
-public enum NotificationType {
-    THANK_YOU_EDIT("thank-you-edit"),
-    EDIT_USER_TALK("edit-user-talk"),
-    MENTION("mention"),
-    EMAIL("email"),
-    WELCOME("welcome"),
-    UNKNOWN("unknown");
-    private String type;
-
-    NotificationType(String type) {
-        this.type = type;
-    }
-
-    public String getType() {
-        return type;
-    }
-
-    public static NotificationType handledValueOf(String name) {
-        for (NotificationType e : values()) {
-            if (e.getType().equals(name)) {
-                return e;
-            }
-        }
-        return UNKNOWN;
-    }
-}

app/src/main/java/fr/free/nrw/commons/notification/models/NotificationType.kt

@@ -0,0 +1,33 @@
+package fr.free.nrw.commons.notification.models
+
+enum class NotificationType(private val type: String) {
+    THANK_YOU_EDIT("thank-you-edit"),
+
+    EDIT_USER_TALK("edit-user-talk"),
+
+    MENTION("mention"),
+
+    EMAIL("email"),
+
+    WELCOME("welcome"),
+
+    UNKNOWN("unknown");
+
+    // Getter for the type property
+    fun getType(): String {
+        return type
+    }
+
+    companion object {
+        // Returns the corresponding NotificationType for a given name or UNKNOWN
+        // if no match is found
+        fun handledValueOf(name: String): NotificationType {
+            for (e in values()) {
+                if (e.type == name) {
+                    return e
+                }
+            }
+            return UNKNOWN
+        }
+    }
+}

app/src/main/java/fr/free/nrw/commons/profile/ProfileActivity.java

@@ -157,7 +157,7 @@ public class ProfileActivity extends BaseActivity {
     @Override
     public void onDestroy() {
         super.onDestroy();
-        compositeDisposable.clear();
+        getCompositeDisposable().clear();
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/profile/achievements/Achievements.kt

@@ -1,104 +1,45 @@
 package fr.free.nrw.commons.profile.achievements
 
 /**
- * Represents Achievements class and stores all the parameters
+ * Represents Achievements data class and stores all the parameters.
+ * Immutable version with default values for optional properties.
  */
-class Achievements {
+data class Achievements(
+    val uniqueUsedImages: Int = 0,
+    val articlesUsingImages: Int = 0,
+    val thanksReceived: Int = 0,
+    val featuredImages: Int = 0,
+    val qualityImages: Int = 0,
+    val imagesUploaded: Int = 0,
+    val revertCount: Int = 0
+) {
     /**
-     * The count of unique images used by the wiki.
+     * Used to calculate the percentages of images that haven't been reverted.
-     * @return The count of unique images used.
+     * Returns 100 if imagesUploaded is 0 to avoid division by zero.
-     * @param uniqueUsedImages The count to set for unique images used.
-     */
-    var uniqueUsedImages = 0
-    private var articlesUsingImages = 0
-
-    /**
-     * The count of thanks received.
-     * @return The count of thanks received.
-     * @param thanksReceived The count to set for thanks received.
-     */
-    var thanksReceived = 0
-
-    /**
-     * The count of featured images.
-     * @return The count of featured images.
-     * @param featuredImages The count to set for featured images.
-     */
-    var featuredImages = 0
-
-    /**
-     * The count of quality images.
-     * @return The count of quality images.
-     * @param qualityImages The count to set for quality images.
-     */
-    var qualityImages = 0
-
-    /**
-     * The count of images uploaded.
-     * @return The count of images uploaded.
-     * @param imagesUploaded The count to set for images uploaded.
-     */
-    var imagesUploaded = 0
-    private var revertCount = 0
-
-    constructor() {}
-
-    /**
-     * constructor for achievements class to set its data members
-     * @param uniqueUsedImages
-     * @param articlesUsingImages
-     * @param thanksReceived
-     * @param featuredImages
-     * @param imagesUploaded
-     * @param revertCount
-     */
-    constructor(
-        uniqueUsedImages: Int,
-        articlesUsingImages: Int,
-        thanksReceived: Int,
-        featuredImages: Int,
-        qualityImages: Int,
-        imagesUploaded: Int,
-        revertCount: Int,
-    ) {
-        this.uniqueUsedImages = uniqueUsedImages
-        this.articlesUsingImages = articlesUsingImages
-        this.thanksReceived = thanksReceived
-        this.featuredImages = featuredImages
-        this.qualityImages = qualityImages
-        this.imagesUploaded = imagesUploaded
-        this.revertCount = revertCount
-    }
-
-    /**
-     * used to calculate the percentages of images that haven't been reverted
-     * @return
      */
     val notRevertPercentage: Int
-        get() =
+        get() = if (imagesUploaded > 0) {
-            try {
+            (imagesUploaded - revertCount) * 100 / imagesUploaded
-                (imagesUploaded - revertCount) * 100 / imagesUploaded
+        } else {
-            } catch (divideByZero: ArithmeticException) {
+            100
-                100
+        }
-            }
 
     companion object {
         /**
-         * Get Achievements object from FeedbackResponse
+         * Get Achievements object from FeedbackResponse.
          *
-         * @param response
+         * @param response The feedback response to convert.
-         * @return
+         * @return An Achievements object with values from the response.
          */
         @JvmStatic
-        fun from(response: FeedbackResponse): Achievements =
+        fun from(response: FeedbackResponse): Achievements = Achievements(
-            Achievements(
+            uniqueUsedImages = response.uniqueUsedImages,
-                response.uniqueUsedImages,
+            articlesUsingImages = response.articlesUsingImages,
-                response.articlesUsingImages,
+            thanksReceived = response.thanksReceived,
-                response.thanksReceived,
+            featuredImages = response.featuredImages.featuredPicturesOnWikimediaCommons,
-                response.featuredImages.featuredPicturesOnWikimediaCommons,
+            qualityImages = response.featuredImages.qualityImages,
-                response.featuredImages.qualityImages,
+            imagesUploaded = 0,  // Assuming imagesUploaded should be 0
-                0,
+            revertCount = response.deletedUploads
-                response.deletedUploads,
+        )
-            )
     }
-}
+}

app/src/main/java/fr/free/nrw/commons/profile/achievements/AchievementsFragment.java

@@ -105,7 +105,7 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
 
         // Used for the setting the size of imageView at runtime
         ConstraintLayout.LayoutParams params = (ConstraintLayout.LayoutParams)
-                binding.achievementBadgeImage.getLayoutParams();
+            binding.achievementBadgeImage.getLayoutParams();
         params.height = (int) (height * BADGE_IMAGE_HEIGHT_RATIO);
         params.width = (int) (width * BADGE_IMAGE_WIDTH_RATIO);
         binding.achievementBadgeImage.requestLayout();
@@ -186,37 +186,37 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
             try{
 
                 compositeDisposable.add(okHttpJsonApiClient
-                        .getAchievements(Objects.requireNonNull(userName))
+                    .getAchievements(Objects.requireNonNull(userName))
-                        .subscribeOn(Schedulers.io())
+                    .subscribeOn(Schedulers.io())
-                        .observeOn(AndroidSchedulers.mainThread())
+                    .observeOn(AndroidSchedulers.mainThread())
-                        .subscribe(
+                    .subscribe(
-                                response -> {
+                        response -> {
-                                    if (response != null) {
+                            if (response != null) {
-                                        setUploadCount(Achievements.from(response));
+                                setUploadCount(Achievements.from(response));
-                                    } else {
+                            } else {
-                                        Timber.d("success");
+                                Timber.d("success");
-                                        binding.layoutImageReverts.setVisibility(View.INVISIBLE);
+                                binding.layoutImageReverts.setVisibility(View.INVISIBLE);
-                                        binding.achievementBadgeImage.setVisibility(View.INVISIBLE);
+                                binding.achievementBadgeImage.setVisibility(View.INVISIBLE);
-                                        // If the number of edits made by the user are more than 150,000
+                                // If the number of edits made by the user are more than 150,000
-                                        // in some cases such high number of wiki edit counts cause the
+                                // in some cases such high number of wiki edit counts cause the
-                                        // achievements calculator to fail in some cases, for more details
+                                // achievements calculator to fail in some cases, for more details
-                                        // refer Issue: #3295
+                                // refer Issue: #3295
-                                        if (numberOfEdits <= 150000) {
+                                if (numberOfEdits <= 150000) {
-                                            showSnackBarWithRetry(false);
+                                    showSnackBarWithRetry(false);
-                                        } else {
+                                } else {
-                                            showSnackBarWithRetry(true);
+                                    showSnackBarWithRetry(true);
-                                        }
-                                    }
-                                },
-                                t -> {
-                                    Timber.e(t, "Fetching achievements statistics failed");
-                                    if (numberOfEdits <= 150000) {
-                                        showSnackBarWithRetry(false);
-                                    } else {
-                                        showSnackBarWithRetry(true);
-                                    }
                                 }
-                        ));
+                            }
+                        },
+                        t -> {
+                            Timber.e(t, "Fetching achievements statistics failed");
+                            if (numberOfEdits <= 150000) {
+                                showSnackBarWithRetry(false);
+                            } else {
+                                showSnackBarWithRetry(true);
+                            }
+                        }
+                    ));
             }
             catch (Exception e){
                 Timber.d(e+"success");
@@ -233,15 +233,15 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
             return;
         }
         compositeDisposable.add(okHttpJsonApiClient
-                .getWikidataEdits(userName)
+            .getWikidataEdits(userName)
-                .subscribeOn(Schedulers.io())
+            .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
+            .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(edits -> {
+            .subscribe(edits -> {
-                    numberOfEdits = edits;
+                numberOfEdits = edits;
-                    binding.wikidataEdits.setText(String.valueOf(edits));
+                binding.wikidataEdits.setText(String.valueOf(edits));
-                }, e -> {
+            }, e -> {
-                    Timber.e("Error:" + e);
+                Timber.e("Error:" + e);
-                }));
+            }));
     }
 
     /**
@@ -255,11 +255,11 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
         if (tooManyAchievements) {
             binding.progressBar.setVisibility(View.GONE);
             ViewUtil.showDismissibleSnackBar(getActivity().findViewById(android.R.id.content),
-                    R.string.achievements_fetch_failed_ultimate_achievement, R.string.retry, view -> setAchievements());
+                R.string.achievements_fetch_failed_ultimate_achievement, R.string.retry, view -> setAchievements());
         } else {
             binding.progressBar.setVisibility(View.GONE);
             ViewUtil.showDismissibleSnackBar(getActivity().findViewById(android.R.id.content),
-                    R.string.achievements_fetch_failed, R.string.retry, view -> setAchievements());
+                R.string.achievements_fetch_failed, R.string.retry, view -> setAchievements());
         }
     }
 
@@ -277,16 +277,16 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
     private void setUploadCount(Achievements achievements) {
         if (checkAccount()) {
             compositeDisposable.add(okHttpJsonApiClient
-                    .getUploadCount(Objects.requireNonNull(userName))
+                .getUploadCount(Objects.requireNonNull(userName))
-                    .subscribeOn(Schedulers.io())
+                .subscribeOn(Schedulers.io())
-                    .observeOn(AndroidSchedulers.mainThread())
+                .observeOn(AndroidSchedulers.mainThread())
-                    .subscribe(
+                .subscribe(
-                            uploadCount -> setAchievementsUploadCount(achievements, uploadCount),
+                    uploadCount -> setAchievementsUploadCount(achievements, uploadCount),
-                            t -> {
+                    t -> {
-                                Timber.e(t, "Fetching upload count failed");
+                        Timber.e(t, "Fetching upload count failed");
-                                onError();
+                        onError();
-                            }
+                    }
-                    ));
+                ));
         }
     }
 
@@ -295,8 +295,18 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
      * @param uploadCount
      */
     private void setAchievementsUploadCount(Achievements achievements, int uploadCount) {
-        achievements.setImagesUploaded(uploadCount);
+        // Create a new instance of Achievements with updated imagesUploaded
-        hideProgressBar(achievements);
+        Achievements updatedAchievements = new Achievements(
+            achievements.getUniqueUsedImages(),
+            achievements.getArticlesUsingImages(),
+            achievements.getThanksReceived(),
+            achievements.getFeaturedImages(),
+            achievements.getQualityImages(),
+            uploadCount,  // Update imagesUploaded with new value
+            achievements.getRevertCount()
+        );
+
+        hideProgressBar(updatedAchievements);
     }
 
     /**
@@ -309,7 +319,7 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
         }else {
             binding.imagesUploadedProgressbar.setVisibility(View.VISIBLE);
             binding.imagesUploadedProgressbar.setProgress
-                    (100*uploadCount/levelInfo.getMaxUploadCount());
+                (100*uploadCount/levelInfo.getMaxUploadCount());
             binding.tvUploadedImages.setText
                 (uploadCount + "/" + levelInfo.getMaxUploadCount());
         }
@@ -318,8 +328,8 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
 
     private void setZeroAchievements() {
         String message = !Objects.equals(sessionManager.getUserName(), userName) ?
-                getString(R.string.no_achievements_yet, userName) :
+            getString(R.string.no_achievements_yet, userName) :
-                getString(R.string.you_have_no_achievements_yet);
+            getString(R.string.you_have_no_achievements_yet);
         DialogUtil.showAlertDialog(getActivity(),
             null,
             message,
@@ -357,7 +367,7 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
 //        binding.imagesUsedByWikiProgressBar.setVisibility(View.VISIBLE);
         binding.thanksReceived.setText(String.valueOf(achievements.getThanksReceived()));
         binding.imagesUsedByWikiProgressBar.setProgress
-                (100 * achievements.getUniqueUsedImages() / levelInfo.getMaxUniqueImages());
+            (100 * achievements.getUniqueUsedImages() / levelInfo.getMaxUniqueImages());
         binding.tvWikiPb.setText(achievements.getUniqueUsedImages() + "/"
             + levelInfo.getMaxUniqueImages());
         binding.imageFeatured.setText(String.valueOf(achievements.getFeaturedImages()));
@@ -366,7 +376,7 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
         levelUpInfoString += " " + levelInfo.getLevelNumber();
         binding.achievementLevel.setText(levelUpInfoString);
         binding.achievementBadgeImage.setImageDrawable(VectorDrawableCompat.create(getResources(), R.drawable.badge,
-                new ContextThemeWrapper(getActivity(), levelInfo.getLevelStyle()).getTheme()));
+            new ContextThemeWrapper(getActivity(), levelInfo.getLevelStyle()).getTheme()));
         binding.achievementBadgeText.setText(Integer.toString(levelInfo.getLevelNumber()));
         BasicKvStore store = new BasicKvStore(this.getContext(), userName);
         store.putString("userAchievementsLevel", Integer.toString(levelInfo.getLevelNumber()));
@@ -378,8 +388,8 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
     private void hideProgressBar(Achievements achievements) {
         if (binding.progressBar != null) {
             levelInfo = LevelController.LevelInfo.from(achievements.getImagesUploaded(),
-                    achievements.getUniqueUsedImages(),
+                achievements.getUniqueUsedImages(),
-                    achievements.getNotRevertPercentage());
+                achievements.getNotRevertPercentage());
             inflateAchievements(achievements);
             setUploadProgress(achievements.getImagesUploaded());
             setImageRevertPercentage(achievements.getNotRevertPercentage());
@@ -479,4 +489,4 @@ public class AchievementsFragment extends CommonsDaggerSupportFragment {
         }
         return true;
     }
-}
+}

app/src/main/java/fr/free/nrw/commons/profile/achievements/FeaturedImages.kt

@@ -6,7 +6,7 @@ import com.google.gson.annotations.SerializedName
  * Represents Featured Images on WikiMedia Commons platform
  * Used by Achievements and FeedbackResponse (objects) of the user
  */
-class FeaturedImages(
+data class FeaturedImages(
     @field:SerializedName("Quality_images") val qualityImages: Int,
     @field:SerializedName("Featured_pictures_on_Wikimedia_Commons") val featuredPicturesOnWikimediaCommons: Int,
 )

app/src/main/java/fr/free/nrw/commons/quiz/QuizActivity.java

@@ -1,146 +0,0 @@
-package fr.free.nrw.commons.quiz;
-
-import android.content.Intent;
-import android.os.Bundle;
-
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.vectordrawable.graphics.drawable.VectorDrawableCompat;
-
-import com.facebook.drawee.drawable.ProgressBarDrawable;
-import com.facebook.drawee.generic.GenericDraweeHierarchyBuilder;
-
-import fr.free.nrw.commons.databinding.ActivityQuizBinding;
-import java.util.ArrayList;
-
-import fr.free.nrw.commons.R;
-
-public class QuizActivity extends AppCompatActivity {
-
-    private ActivityQuizBinding binding;
-    private final QuizController quizController = new QuizController();
-    private ArrayList<QuizQuestion> quiz = new ArrayList<>();
-    private int questionIndex = 0;
-    private int score;
-    /**
-     * isPositiveAnswerChecked : represents yes click event
-     */
-    private boolean isPositiveAnswerChecked;
-    /**
-     * isNegativeAnswerChecked : represents no click event
-     */
-    private boolean isNegativeAnswerChecked;
-
-    @Override
-    protected void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        binding = ActivityQuizBinding.inflate(getLayoutInflater());
-        setContentView(binding.getRoot());
-
-        quizController.initialize(this);
-        setSupportActionBar(binding.toolbar.toolbar);
-        binding.nextButton.setOnClickListener(view -> notKnowAnswer());
-        displayQuestion();
-    }
-
-    /**
-     * to move to next question and check whether answer is selected or not
-     */
-    public void setNextQuestion(){
-        if ( questionIndex <= quiz.size() && (isPositiveAnswerChecked || isNegativeAnswerChecked)) {
-            evaluateScore();
-        }
-    }
-
-    public void notKnowAnswer(){
-        customAlert("Information", quiz.get(questionIndex).getAnswerMessage());
-    }
-
-    /**
-     * to give warning before ending quiz
-     */
-    @Override
-    public void onBackPressed() {
-        new AlertDialog.Builder(this)
-            .setTitle(getResources().getString(R.string.warning))
-            .setMessage(getResources().getString(R.string.quiz_back_button))
-            .setPositiveButton(R.string.continue_message, (dialog, which) -> {
-                final Intent intent = new Intent(this, QuizResultActivity.class);
-                dialog.dismiss();
-                intent.putExtra("QuizResult", score);
-                startActivity(intent);
-            })
-            .setNegativeButton("Cancel", (dialogInterface, i) -> dialogInterface.dismiss())
-            .create()
-            .show();
-    }
-
-    /**
-     * to display the question
-     */
-    public void displayQuestion() {
-        quiz = quizController.getQuiz();
-        binding.question.questionText.setText(quiz.get(questionIndex).getQuestion());
-        binding.questionTitle.setText(
-            getResources().getString(R.string.question) +
-                quiz.get(questionIndex).getQuestionNumber()
-        );
-        binding.question.questionImage.setHierarchy(GenericDraweeHierarchyBuilder
-                .newInstance(getResources())
-                .setFailureImage(VectorDrawableCompat.create(getResources(),
-                        R.drawable.ic_error_outline_black_24dp, getTheme()))
-                .setProgressBarImage(new ProgressBarDrawable())
-                .build());
-
-        binding.question.questionImage.setImageURI(quiz.get(questionIndex).getUrl());
-        isPositiveAnswerChecked = false;
-        isNegativeAnswerChecked = false;
-        binding.answer.quizPositiveAnswer.setOnClickListener(view -> {
-            isPositiveAnswerChecked = true;
-            setNextQuestion();
-        });
-        binding.answer.quizNegativeAnswer.setOnClickListener(view -> {
-            isNegativeAnswerChecked = true;
-            setNextQuestion();
-        });
-    }
-
-    /**
-     * to evaluate score and check whether answer is correct or wrong
-     */
-    public void evaluateScore() {
-        if ((quiz.get(questionIndex).isAnswer() && isPositiveAnswerChecked) ||
-                (!quiz.get(questionIndex).isAnswer() && isNegativeAnswerChecked) ){
-            customAlert(getResources().getString(R.string.correct),
-                quiz.get(questionIndex).getAnswerMessage());
-            score++;
-        } else {
-            customAlert(getResources().getString(R.string.wrong),
-                quiz.get(questionIndex).getAnswerMessage());
-        }
-    }
-
-    /**
-     * to display explanation after each answer, update questionIndex and move to next question
-     * @param title the alert title
-     * @param Message the alert message
-     */
-    public void customAlert(final String title, final String Message) {
-        new AlertDialog.Builder(this)
-            .setTitle(title)
-            .setMessage(Message)
-            .setPositiveButton(R.string.continue_message, (dialog, which) -> {
-                questionIndex++;
-                if (questionIndex == quiz.size()) {
-                    final Intent intent = new Intent(this, QuizResultActivity.class);
-                    dialog.dismiss();
-                    intent.putExtra("QuizResult", score);
-                    startActivity(intent);
-                } else {
-                    displayQuestion();
-                }
-            })
-            .create()
-            .show();
-    }
-}

app/src/main/java/fr/free/nrw/commons/quiz/QuizActivity.kt

@@ -0,0 +1,154 @@
+package fr.free.nrw.commons.quiz
+
+import android.annotation.SuppressLint
+import android.content.Intent
+import android.os.Bundle
+
+import androidx.appcompat.app.AlertDialog
+import androidx.appcompat.app.AppCompatActivity
+import androidx.vectordrawable.graphics.drawable.VectorDrawableCompat
+
+import com.facebook.drawee.drawable.ProgressBarDrawable
+import com.facebook.drawee.generic.GenericDraweeHierarchyBuilder
+
+import fr.free.nrw.commons.databinding.ActivityQuizBinding
+import java.util.ArrayList
+
+import fr.free.nrw.commons.R
+
+
+class QuizActivity : AppCompatActivity() {
+
+    private lateinit var binding: ActivityQuizBinding
+    private val quizController = QuizController()
+    private var quiz = ArrayList<QuizQuestion>()
+    private var questionIndex = 0
+    private var score = 0
+
+    /**
+     * isPositiveAnswerChecked : represents yes click event
+     */
+    private var isPositiveAnswerChecked = false
+
+    /**
+     * isNegativeAnswerChecked : represents no click event
+     */
+    private var isNegativeAnswerChecked = false
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = ActivityQuizBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+
+        quizController.initialize(this)
+        setSupportActionBar(binding.toolbar.toolbar)
+        binding.nextButton.setOnClickListener { notKnowAnswer() }
+        displayQuestion()
+    }
+
+    /**
+     * To move to next question and check whether answer is selected or not
+     */
+    fun setNextQuestion() {
+        if (questionIndex <= quiz.size && (isPositiveAnswerChecked || isNegativeAnswerChecked)) {
+            evaluateScore()
+        }
+    }
+
+    private fun notKnowAnswer() {
+        customAlert("Information", quiz[questionIndex].answerMessage)
+    }
+
+    /**
+     * To give warning before ending quiz
+     */
+    override fun onBackPressed() {
+        AlertDialog.Builder(this)
+            .setTitle(getString(R.string.warning))
+            .setMessage(getString(R.string.quiz_back_button))
+            .setPositiveButton(R.string.continue_message) { dialog, _ ->
+                val intent = Intent(this, QuizResultActivity::class.java)
+                dialog.dismiss()
+                intent.putExtra("QuizResult", score)
+                startActivity(intent)
+            }
+            .setNegativeButton("Cancel") { dialogInterface, _ -> dialogInterface.dismiss() }
+            .create()
+            .show()
+    }
+
+    /**
+     * To display the question
+     */
+    @SuppressLint("SetTextI18n")
+    private fun displayQuestion() {
+        quiz = quizController.getQuiz()
+        binding.question.questionText.text = quiz[questionIndex].question
+        binding.questionTitle.text = getString(R.string.question) + quiz[questionIndex].questionNumber
+
+        binding.question.questionImage.hierarchy = GenericDraweeHierarchyBuilder
+            .newInstance(resources)
+            .setFailureImage(VectorDrawableCompat.create(resources, R.drawable.ic_error_outline_black_24dp, theme))
+            .setProgressBarImage(ProgressBarDrawable())
+            .build()
+
+        binding.question.questionImage.setImageURI(quiz[questionIndex].getUrl())
+        isPositiveAnswerChecked = false
+        isNegativeAnswerChecked = false
+
+        binding.answer.quizPositiveAnswer.setOnClickListener {
+            isPositiveAnswerChecked = true
+            setNextQuestion()
+        }
+        binding.answer.quizNegativeAnswer.setOnClickListener {
+            isNegativeAnswerChecked = true
+            setNextQuestion()
+        }
+    }
+
+    /**
+     * To evaluate score and check whether answer is correct or wrong
+     */
+    fun evaluateScore() {
+        if (
+            (quiz[questionIndex].isAnswer && isPositiveAnswerChecked)
+                ||
+            (!quiz[questionIndex].isAnswer && isNegativeAnswerChecked)
+            ) {
+            customAlert(
+                getString(R.string.correct),
+                quiz[questionIndex].answerMessage
+            )
+            score++
+        } else {
+            customAlert(
+                getString(R.string.wrong),
+                quiz[questionIndex].answerMessage
+            )
+        }
+    }
+
+    /**
+     * To display explanation after each answer, update questionIndex and move to next question
+     * @param title The alert title
+     * @param message The alert message
+     */
+    fun customAlert(title: String, message: String) {
+        AlertDialog.Builder(this)
+            .setTitle(title)
+            .setMessage(message)
+            .setPositiveButton(R.string.continue_message) { dialog, _ ->
+                questionIndex++
+                if (questionIndex == quiz.size) {
+                    val intent = Intent(this, QuizResultActivity::class.java)
+                    dialog.dismiss()
+                    intent.putExtra("QuizResult", score)
+                    startActivity(intent)
+                } else {
+                    displayQuestion()
+                }
+            }
+            .create()
+            .show()
+    }
+}

app/src/main/java/fr/free/nrw/commons/quiz/QuizChecker.java

@@ -1,167 +0,0 @@
-package fr.free.nrw.commons.quiz;
-
-import android.annotation.SuppressLint;
-import android.app.Activity;
-import android.content.Intent;
-
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.WelcomeActivity;
-import fr.free.nrw.commons.auth.SessionManager;
-import fr.free.nrw.commons.kvstore.JsonKvStore;
-import fr.free.nrw.commons.mwapi.OkHttpJsonApiClient;
-import fr.free.nrw.commons.utils.DialogUtil;
-import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.disposables.CompositeDisposable;
-import io.reactivex.schedulers.Schedulers;
-import timber.log.Timber;
-
-/**
- * fetches the number of images uploaded and number of images reverted.
- * Then it calculates the percentage of the images reverted
- * if the percentage of images reverted after last quiz exceeds 50% and number of images uploaded is
- * greater than 50, then quiz is popped up
- */
-@Singleton
-public class QuizChecker {
-
-    private int revertCount ;
-    private int totalUploadCount ;
-    private boolean isRevertCountFetched;
-    private boolean isUploadCountFetched;
-
-    private CompositeDisposable compositeDisposable = new CompositeDisposable();
-
-    private final SessionManager sessionManager;
-    private final OkHttpJsonApiClient okHttpJsonApiClient;
-    private final JsonKvStore revertKvStore;
-
-    private static final int UPLOAD_COUNT_THRESHOLD = 5;
-    private static final String REVERT_PERCENTAGE_FOR_MESSAGE = "50%";
-    private final String REVERT_SHARED_PREFERENCE = "revertCount";
-    private final String UPLOAD_SHARED_PREFERENCE = "uploadCount";
-
-    /**
-     * constructor to set the parameters for quiz
-     * @param sessionManager
-     * @param okHttpJsonApiClient
-     */
-    @Inject
-    public QuizChecker(SessionManager sessionManager,
-                       OkHttpJsonApiClient okHttpJsonApiClient,
-                       @Named("default_preferences") JsonKvStore revertKvStore) {
-        this.sessionManager = sessionManager;
-        this.okHttpJsonApiClient = okHttpJsonApiClient;
-        this.revertKvStore = revertKvStore;
-    }
-
-    public void initQuizCheck(Activity activity) {
-        calculateRevertParameterAndShowQuiz(activity);
-    }
-
-    public void cleanup() {
-        compositeDisposable.clear();
-    }
-
-    /**
-     * to fet the total number of images uploaded
-     */
-    private void setUploadCount() {
-        compositeDisposable.add(okHttpJsonApiClient
-                .getUploadCount(sessionManager.getUserName())
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(this::setTotalUploadCount,
-                            t -> Timber.e(t, "Fetching upload count failed")
-                    ));
-    }
-
-    /**
-     * set the sub Title of Contibutions Activity and
-     * call function to check for quiz
-     * @param uploadCount user's upload count
-     */
-    private void setTotalUploadCount(int uploadCount) {
-        totalUploadCount = uploadCount - revertKvStore.getInt(UPLOAD_SHARED_PREFERENCE, 0);
-        if ( totalUploadCount < 0){
-            totalUploadCount = 0;
-            revertKvStore.putInt(UPLOAD_SHARED_PREFERENCE, 0);
-        }
-        isUploadCountFetched = true;
-    }
-
-    /**
-     * To call the API to get reverts count in form of JSONObject
-     */
-    private void setRevertCount() {
-        compositeDisposable.add(okHttpJsonApiClient
-                .getAchievements(sessionManager.getUserName())
-                    .subscribeOn(Schedulers.io())
-                    .observeOn(AndroidSchedulers.mainThread())
-                    .subscribe(
-                            response -> {
-                                if (response != null) {
-                                    setRevertParameter(response.getDeletedUploads());
-                                }
-                            }, throwable -> Timber.e(throwable, "Fetching feedback failed"))
-            );
-    }
-
-    /**
-     * to calculate the number of images reverted after previous quiz
-     * @param revertCountFetched count of deleted uploads
-     */
-    private void setRevertParameter(int revertCountFetched) {
-        revertCount = revertCountFetched - revertKvStore.getInt(REVERT_SHARED_PREFERENCE, 0);
-        if (revertCount < 0){
-            revertCount = 0;
-            revertKvStore.putInt(REVERT_SHARED_PREFERENCE, 0);
-        }
-        isRevertCountFetched = true;
-    }
-
-    /**
-     * to check whether the criterion to call quiz is satisfied
-     */
-    private void calculateRevertParameterAndShowQuiz(Activity activity) {
-        setUploadCount();
-        setRevertCount();
-        if ( revertCount < 0 || totalUploadCount < 0){
-            revertKvStore.putInt(REVERT_SHARED_PREFERENCE, 0);
-            revertKvStore.putInt(UPLOAD_SHARED_PREFERENCE, 0);
-            return;
-        }
-        if (isRevertCountFetched && isUploadCountFetched &&
-                totalUploadCount >= UPLOAD_COUNT_THRESHOLD &&
-                (revertCount * 100) / totalUploadCount >= 50) {
-            callQuiz(activity);
-        }
-    }
-
-    /**
-     * Alert which prompts to quiz
-     */
-    @SuppressLint("StringFormatInvalid")
-    private void callQuiz(Activity activity) {
-        DialogUtil.showAlertDialog(activity,
-                activity.getString(R.string.quiz),
-                activity.getString(R.string.quiz_alert_message, REVERT_PERCENTAGE_FOR_MESSAGE),
-                activity.getString(R.string.about_translate_proceed),
-                activity.getString(android.R.string.cancel),
-                () -> startQuizActivity(activity),
-                null);
-    }
-
-    private void startQuizActivity(Activity activity) {
-        int newRevetSharedPrefs = revertCount + revertKvStore.getInt(REVERT_SHARED_PREFERENCE, 0);
-        revertKvStore.putInt(REVERT_SHARED_PREFERENCE, newRevetSharedPrefs);
-        int newUploadCount = totalUploadCount + revertKvStore.getInt(UPLOAD_SHARED_PREFERENCE, 0);
-        revertKvStore.putInt(UPLOAD_SHARED_PREFERENCE, newUploadCount);
-        Intent i = new Intent(activity, WelcomeActivity.class);
-        i.putExtra("isQuiz", true);
-        activity.startActivity(i);
-    }
-}

app/src/main/java/fr/free/nrw/commons/quiz/QuizChecker.kt

@@ -0,0 +1,175 @@
+package fr.free.nrw.commons.quiz
+
+import android.annotation.SuppressLint
+import android.app.Activity
+import android.content.Intent
+
+import javax.inject.Inject
+import javax.inject.Named
+import javax.inject.Singleton
+
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.WelcomeActivity
+import fr.free.nrw.commons.auth.SessionManager
+import fr.free.nrw.commons.kvstore.JsonKvStore
+import fr.free.nrw.commons.mwapi.OkHttpJsonApiClient
+import fr.free.nrw.commons.utils.DialogUtil
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.disposables.CompositeDisposable
+import io.reactivex.schedulers.Schedulers
+import timber.log.Timber
+
+
+/**
+ * Fetches the number of images uploaded and number of images reverted.
+ * Then it calculates the percentage of the images reverted.
+ * If the percentage of images reverted after the last quiz exceeds 50% and number of images uploaded is
+ * greater than 50, then the quiz is popped up.
+ */
+@Singleton
+class QuizChecker @Inject constructor(
+    private val sessionManager: SessionManager,
+    private val okHttpJsonApiClient: OkHttpJsonApiClient,
+    @Named("default_preferences") private val revertKvStore: JsonKvStore
+) {
+
+    private var revertCount = 0
+    private var totalUploadCount = 0
+    private var isRevertCountFetched = false
+    private var isUploadCountFetched = false
+
+    private val compositeDisposable = CompositeDisposable()
+
+    private val UPLOAD_COUNT_THRESHOLD = 5
+    private val REVERT_PERCENTAGE_FOR_MESSAGE = "50%"
+    private val REVERT_SHARED_PREFERENCE = "revertCount"
+    private val UPLOAD_SHARED_PREFERENCE = "uploadCount"
+
+    /**
+     * Initializes quiz check by calculating revert parameters and showing quiz if necessary
+     */
+    fun initQuizCheck(activity: Activity) {
+        calculateRevertParameterAndShowQuiz(activity)
+    }
+
+    /**
+     * Clears disposables to avoid memory leaks
+     */
+    fun cleanup() {
+        compositeDisposable.clear()
+    }
+
+    /**
+     * Fetches the total number of images uploaded
+     */
+    private fun setUploadCount() {
+        compositeDisposable.add(
+            okHttpJsonApiClient.getUploadCount(sessionManager.userName)
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(
+                    { uploadCount -> setTotalUploadCount(uploadCount) },
+                    { t -> Timber.e(t, "Fetching upload count failed") }
+                )
+        )
+    }
+
+    /**
+     * Sets the total upload count after subtracting stored preference
+     * @param uploadCount User's upload count
+     */
+    private fun setTotalUploadCount(uploadCount: Int) {
+        totalUploadCount = uploadCount - revertKvStore.getInt(
+            UPLOAD_SHARED_PREFERENCE,
+            0
+        )
+        if (totalUploadCount < 0) {
+            totalUploadCount = 0
+            revertKvStore.putInt(UPLOAD_SHARED_PREFERENCE, 0)
+        }
+        isUploadCountFetched = true
+    }
+
+    /**
+     * Fetches the revert count using the API
+     */
+    private fun setRevertCount() {
+        compositeDisposable.add(
+            okHttpJsonApiClient.getAchievements(sessionManager.userName)
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(
+                    { response ->
+                        response?.let { setRevertParameter(it.deletedUploads) }
+                    },
+                    { throwable -> Timber.e(throwable, "Fetching feedback failed") }
+                )
+        )
+    }
+
+    /**
+     * Calculates the number of images reverted after the previous quiz
+     * @param revertCountFetched Count of deleted uploads
+     */
+    private fun setRevertParameter(revertCountFetched: Int) {
+        revertCount = revertCountFetched - revertKvStore.getInt(REVERT_SHARED_PREFERENCE, 0)
+        if (revertCount < 0) {
+            revertCount = 0
+            revertKvStore.putInt(REVERT_SHARED_PREFERENCE, 0)
+        }
+        isRevertCountFetched = true
+    }
+
+    /**
+     * Checks whether the criteria for calling the quiz are satisfied
+     */
+    private fun calculateRevertParameterAndShowQuiz(activity: Activity) {
+        setUploadCount()
+        setRevertCount()
+
+        if (revertCount < 0 || totalUploadCount < 0) {
+            revertKvStore.putInt(REVERT_SHARED_PREFERENCE, 0)
+            revertKvStore.putInt(UPLOAD_SHARED_PREFERENCE, 0)
+            return
+        }
+
+        if (isRevertCountFetched && isUploadCountFetched &&
+            totalUploadCount >= UPLOAD_COUNT_THRESHOLD &&
+            (revertCount * 100) / totalUploadCount >= 50
+        ) {
+            callQuiz(activity)
+        }
+    }
+
+    /**
+     * Displays an alert prompting the user to take the quiz
+     */
+    @SuppressLint("StringFormatInvalid")
+    private fun callQuiz(activity: Activity) {
+        DialogUtil.showAlertDialog(
+            activity,
+            activity.getString(R.string.quiz),
+            activity.getString(R.string.quiz_alert_message, REVERT_PERCENTAGE_FOR_MESSAGE),
+            activity.getString(R.string.about_translate_proceed),
+            activity.getString(android.R.string.cancel),
+            { startQuizActivity(activity) },
+            null
+        )
+    }
+
+    /**
+     * Starts the quiz activity and updates preferences for revert and upload counts
+     */
+    private fun startQuizActivity(activity: Activity) {
+        val newRevertSharedPrefs = revertCount + revertKvStore.getInt(REVERT_SHARED_PREFERENCE, 0)
+        revertKvStore.putInt(REVERT_SHARED_PREFERENCE, newRevertSharedPrefs)
+
+        val newUploadCount = totalUploadCount + revertKvStore.getInt(UPLOAD_SHARED_PREFERENCE, 0)
+        revertKvStore.putInt(UPLOAD_SHARED_PREFERENCE, newUploadCount)
+
+        val intent = Intent(activity, WelcomeActivity::class.java).apply {
+            putExtra("isQuiz", true)
+        }
+        activity.startActivity(intent)
+    }
+}

app/src/main/java/fr/free/nrw/commons/quiz/QuizController.java

@@ -1,63 +0,0 @@
-package fr.free.nrw.commons.quiz;
-
-import android.content.Context;
-
-import java.util.ArrayList;
-
-import fr.free.nrw.commons.R;
-
-/**
- * controls the quiz in the Activity
- */
-public class QuizController {
-
-    ArrayList<QuizQuestion> quiz = new ArrayList<>();
-
-    private final String URL_FOR_SELFIE = "https://i.imgur.com/0fMYcpM.jpg";
-    private final String URL_FOR_TAJ_MAHAL = "https://upload.wikimedia.org/wikipedia/commons/1/15/Taj_Mahal-03.jpg";
-    private final String URL_FOR_BLURRY_IMAGE = "https://i.imgur.com/Kepb5jR.jpg";
-    private final String URL_FOR_SCREENSHOT = "https://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Social_media_app_mockup_screenshot.svg/500px-Social_media_app_mockup_screenshot.svg.png";
-    private final String URL_FOR_EVENT = "https://upload.wikimedia.org/wikipedia/commons/5/51/HouseBuildingInNorthernVietnam.jpg";
-
-    public void initialize(Context context){
-        QuizQuestion q1 = new QuizQuestion(1,
-                context.getString(R.string.quiz_question_string),
-                URL_FOR_SELFIE,
-                false,
-                context.getString(R.string.selfie_answer));
-        quiz.add(q1);
-
-        QuizQuestion q2 = new QuizQuestion(2,
-                context.getString(R.string.quiz_question_string),
-                URL_FOR_TAJ_MAHAL,
-                true,
-                context.getString(R.string.taj_mahal_answer));
-        quiz.add(q2);
-
-        QuizQuestion q3 = new QuizQuestion(3,
-                context.getString(R.string.quiz_question_string),
-                URL_FOR_BLURRY_IMAGE,
-                false,
-                context.getString(R.string.blurry_image_answer));
-        quiz.add(q3);
-
-        QuizQuestion q4 = new QuizQuestion(4,
-                context.getString(R.string.quiz_screenshot_question),
-                URL_FOR_SCREENSHOT,
-                false,
-                context.getString(R.string.screenshot_answer));
-        quiz.add(q4);
-
-        QuizQuestion q5 = new QuizQuestion(5,
-                context.getString(R.string.quiz_question_string),
-                URL_FOR_EVENT,
-                true,
-                context.getString(R.string.construction_event_answer));
-        quiz.add(q5);
-
-    }
-
-    public ArrayList<QuizQuestion> getQuiz() {
-        return quiz;
-    }
-}

app/src/main/java/fr/free/nrw/commons/quiz/QuizController.kt

@@ -0,0 +1,76 @@
+package fr.free.nrw.commons.quiz
+
+import android.content.Context
+
+import java.util.ArrayList
+
+import fr.free.nrw.commons.R
+
+
+/**
+ * Controls the quiz in the Activity
+ */
+class QuizController {
+
+    private val quiz: ArrayList<QuizQuestion> = ArrayList()
+
+    private val URL_FOR_SELFIE = "https://i.imgur.com/0fMYcpM.jpg"
+    private val URL_FOR_TAJ_MAHAL = "https://upload.wikimedia.org/wikipedia/commons/1/15/Taj_Mahal-03.jpg"
+    private val URL_FOR_BLURRY_IMAGE = "https://i.imgur.com/Kepb5jR.jpg"
+    private val URL_FOR_SCREENSHOT = "https://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Social_media_app_mockup_screenshot.svg/500px-Social_media_app_mockup_screenshot.svg.png"
+    private val URL_FOR_EVENT = "https://upload.wikimedia.org/wikipedia/commons/5/51/HouseBuildingInNorthernVietnam.jpg"
+
+    fun initialize(context: Context) {
+        val q1 = QuizQuestion(
+            1,
+            context.getString(R.string.quiz_question_string),
+            URL_FOR_SELFIE,
+            false,
+            context.getString(R.string.selfie_answer)
+        )
+        quiz.add(q1)
+
+        val q2 = QuizQuestion(
+            2,
+            context.getString(R.string.quiz_question_string),
+            URL_FOR_TAJ_MAHAL,
+            true,
+            context.getString(R.string.taj_mahal_answer)
+        )
+        quiz.add(q2)
+
+        val q3 = QuizQuestion(
+            3,
+            context.getString(R.string.quiz_question_string),
+            URL_FOR_BLURRY_IMAGE,
+            false,
+            context.getString(R.string.blurry_image_answer)
+        )
+        quiz.add(q3)
+
+        val q4 = QuizQuestion(
+            4,
+            context.getString(R.string.quiz_screenshot_question),
+            URL_FOR_SCREENSHOT,
+            false,
+            context.getString(R.string.screenshot_answer)
+        )
+        quiz.add(q4)
+
+        val q5 = QuizQuestion(
+            5,
+            context.getString(R.string.quiz_question_string),
+            URL_FOR_EVENT,
+            true,
+            context.getString(R.string.construction_event_answer)
+        )
+        quiz.add(q5)
+    }
+
+    fun getQuiz(): ArrayList<QuizQuestion> {
+        return quiz
+    }
+}
+
+
+

app/src/main/java/fr/free/nrw/commons/quiz/QuizResultActivity.java

@@ -1,188 +0,0 @@
-package fr.free.nrw.commons.quiz;
-
-import android.content.Context;
-import android.content.Intent;
-import android.graphics.Bitmap;
-import android.net.Uri;
-import android.os.Bundle;
-import android.view.LayoutInflater;
-import android.view.Menu;
-import android.view.MenuItem;
-import android.view.View;
-import android.widget.ImageView;
-import android.widget.TextView;
-
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
-
-import fr.free.nrw.commons.databinding.ActivityQuizResultBinding;
-import java.io.File;
-import java.io.FileOutputStream;
-
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.contributions.MainActivity;
-
-
-/**
- *  Displays the final score of quiz and congratulates the user
- */
-public class QuizResultActivity extends AppCompatActivity {
-
-    private ActivityQuizResultBinding binding;
-    private final int NUMBER_OF_QUESTIONS = 5;
-    private final int MULTIPLIER_TO_GET_PERCENTAGE = 20;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        binding = ActivityQuizResultBinding.inflate(getLayoutInflater());
-        setContentView(binding.getRoot());
-
-        setSupportActionBar(binding.toolbar.toolbar);
-
-        binding.quizResultNext.setOnClickListener(view -> launchContributionActivity());
-
-        if ( getIntent() != null) {
-            Bundle extras = getIntent().getExtras();
-            int score = extras.getInt("QuizResult");
-            setScore(score);
-        }else{
-            startActivityWithFlags(
-                    this, MainActivity.class, Intent.FLAG_ACTIVITY_CLEAR_TOP,
-                    Intent.FLAG_ACTIVITY_SINGLE_TOP);
-            super.onBackPressed();
-        }
-    }
-
-    @Override
-    protected void onDestroy() {
-        binding = null;
-        super.onDestroy();
-    }
-
-    /**
-     * to calculate and display percentage and score
-     * @param score
-     */
-    public void setScore(int score) {
-        final int scorePercent = score * MULTIPLIER_TO_GET_PERCENTAGE;
-        binding.resultProgressBar.setProgress(scorePercent);
-        binding.tvResultProgress.setText(score +" / " + NUMBER_OF_QUESTIONS);
-        final String message = getResources().getString(R.string.congratulatory_message_quiz,scorePercent + "%");
-        binding.congratulatoryMessage.setText(message);
-    }
-
-    /**
-     * to go to Contibutions Activity
-     */
-    public void launchContributionActivity(){
-        startActivityWithFlags(
-                this, MainActivity.class, Intent.FLAG_ACTIVITY_CLEAR_TOP,
-                Intent.FLAG_ACTIVITY_SINGLE_TOP);
-    }
-
-    @Override
-    public void onBackPressed() {
-        startActivityWithFlags(
-                this, MainActivity.class, Intent.FLAG_ACTIVITY_CLEAR_TOP,
-                Intent.FLAG_ACTIVITY_SINGLE_TOP);
-        super.onBackPressed();
-    }
-
-    /**
-     * Function to call intent to an activity
-     * @param context
-     * @param cls
-     * @param flags
-     * @param <T>
-     */
-    public static <T> void startActivityWithFlags(Context context, Class<T> cls, int... flags) {
-        Intent intent = new Intent(context, cls);
-        for (int flag: flags) {
-            intent.addFlags(flag);
-        }
-        context.startActivity(intent);
-    }
-
-    /**
-     * to inflate menu
-     * @param menu
-     * @return
-     */
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        // Inflate the menu; this adds items to the action bar if it is present.
-        getMenuInflater().inflate(R.menu.menu_about, menu);
-        return true;
-    }
-
-    /**
-     * if share option selected then take screenshot and launch alert
-     * @param item
-     * @return
-     */
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        int id = item.getItemId();
-        if (id == R.id.share_app_icon) {
-            View rootView = getWindow().getDecorView().findViewById(android.R.id.content);
-            Bitmap screenShot = getScreenShot(rootView);
-            showAlert(screenShot);
-        }
-
-        return super.onOptionsItemSelected(item);
-    }
-
-    /**
-     * to store the screenshot of image in bitmap variable temporarily
-     * @param view
-     * @return
-     */
-    public static Bitmap getScreenShot(View view) {
-        View screenView = view.getRootView();
-        screenView.setDrawingCacheEnabled(true);
-        Bitmap bitmap = Bitmap.createBitmap(screenView.getDrawingCache());
-        screenView.setDrawingCacheEnabled(false);
-        return bitmap;
-    }
-
-    /**
-     * share the screenshot through social media
-     * @param bitmap
-     */
-    void shareScreen(Bitmap bitmap) {
-        try {
-            File file = new File(this.getExternalCacheDir(),"screen.png");
-            FileOutputStream fOut = new FileOutputStream(file);
-            bitmap.compress(Bitmap.CompressFormat.PNG, 100, fOut);
-            fOut.flush();
-            fOut.close();
-            file.setReadable(true, false);
-            final Intent intent = new Intent(android.content.Intent.ACTION_SEND);
-            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-            intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(file));
-            intent.setType("image/png");
-            startActivity(Intent.createChooser(intent, getString(R.string.share_image_via)));
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-
-    /**
-     * It display the alertDialog with Image of screenshot
-     * @param screenshot
-     */
-    public void showAlert(Bitmap screenshot) {
-        AlertDialog.Builder alertadd = new AlertDialog.Builder(QuizResultActivity.this);
-        LayoutInflater factory = LayoutInflater.from(QuizResultActivity.this);
-        final View view = factory.inflate(R.layout.image_alert_layout, null);
-        ImageView screenShotImage = view.findViewById(R.id.alert_image);
-        screenShotImage.setImageBitmap(screenshot);
-        TextView shareMessage = view.findViewById(R.id.alert_text);
-        shareMessage.setText(R.string.quiz_result_share_message);
-        alertadd.setView(view);
-        alertadd.setPositiveButton(R.string.about_translate_proceed, (dialog, which) -> shareScreen(screenshot));
-        alertadd.setNegativeButton(android.R.string.cancel, (dialog, which) -> dialog.cancel());
-        alertadd.show();
-    }
-}

app/src/main/java/fr/free/nrw/commons/quiz/QuizResultActivity.kt

@@ -0,0 +1,192 @@
+package fr.free.nrw.commons.quiz
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.Intent
+import android.graphics.Bitmap
+import android.net.Uri
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.Menu
+import android.view.MenuItem
+import android.view.View
+import android.widget.ImageView
+import android.widget.TextView
+
+import androidx.appcompat.app.AlertDialog
+import androidx.appcompat.app.AppCompatActivity
+
+import fr.free.nrw.commons.databinding.ActivityQuizResultBinding
+import java.io.File
+import java.io.FileOutputStream
+
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.contributions.MainActivity
+
+
+/**
+ * Displays the final score of quiz and congratulates the user
+ */
+class QuizResultActivity : AppCompatActivity() {
+
+    private var binding: ActivityQuizResultBinding? = null
+    private val NUMBER_OF_QUESTIONS = 5
+    private val MULTIPLIER_TO_GET_PERCENTAGE = 20
+
+    public override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = ActivityQuizResultBinding.inflate(layoutInflater)
+        setContentView(binding?.root)
+
+        setSupportActionBar(binding?.toolbar?.toolbar)
+
+        binding?.quizResultNext?.setOnClickListener {
+            launchContributionActivity()
+        }
+
+        intent?.extras?.let { extras ->
+            val score = extras.getInt("QuizResult", 0)
+            setScore(score)
+        } ?: run {
+            startActivityWithFlags(
+                this, MainActivity::class.java,
+                Intent.FLAG_ACTIVITY_CLEAR_TOP, Intent.FLAG_ACTIVITY_SINGLE_TOP
+            )
+            super.onBackPressed()
+        }
+    }
+
+    override fun onDestroy() {
+        binding = null
+        super.onDestroy()
+    }
+
+    /**
+     * To calculate and display percentage and score
+     * @param score
+     */
+    @SuppressLint("StringFormatInvalid", "SetTextI18n")
+    fun setScore(score: Int) {
+        val scorePercent = score * MULTIPLIER_TO_GET_PERCENTAGE
+        binding?.resultProgressBar?.progress = scorePercent
+        binding?.tvResultProgress?.text = "$score / $NUMBER_OF_QUESTIONS"
+        val message = resources.getString(R.string.congratulatory_message_quiz, "$scorePercent%")
+        binding?.congratulatoryMessage?.text = message
+    }
+
+    /**
+     * To go to Contributions Activity
+     */
+    fun launchContributionActivity() {
+        startActivityWithFlags(
+            this, MainActivity::class.java,
+            Intent.FLAG_ACTIVITY_CLEAR_TOP, Intent.FLAG_ACTIVITY_SINGLE_TOP
+        )
+    }
+
+    override fun onBackPressed() {
+        startActivityWithFlags(
+            this, MainActivity::class.java,
+            Intent.FLAG_ACTIVITY_CLEAR_TOP, Intent.FLAG_ACTIVITY_SINGLE_TOP
+        )
+        super.onBackPressed()
+    }
+
+    /**
+     * Function to call intent to an activity
+     * @param context
+     * @param cls
+     * @param flags
+     */
+    companion object {
+        fun <T> startActivityWithFlags(context: Context, cls: Class<T>, vararg flags: Int) {
+            val intent = Intent(context, cls)
+            flags.forEach { flag -> intent.addFlags(flag) }
+            context.startActivity(intent)
+        }
+    }
+
+    /**
+     * To inflate menu
+     * @param menu
+     * @return
+     */
+    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
+        // Inflate the menu; this adds items to the action bar if it is present.
+        menuInflater.inflate(R.menu.menu_about, menu)
+        return true
+    }
+
+    /**
+     * If share option selected then take screenshot and launch alert
+     * @param item
+     * @return
+     */
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        if (item.itemId == R.id.share_app_icon) {
+            val rootView = window.decorView.findViewById<View>(android.R.id.content)
+            val screenShot = getScreenShot(rootView)
+            showAlert(screenShot)
+        }
+        return super.onOptionsItemSelected(item)
+    }
+
+    /**
+     * To store the screenshot of image in bitmap variable temporarily
+     * @param view
+     * @return
+     */
+    fun getScreenShot(view: View): Bitmap {
+        val screenView = view.rootView
+        screenView.isDrawingCacheEnabled = true
+        val bitmap = Bitmap.createBitmap(screenView.drawingCache)
+        screenView.isDrawingCacheEnabled = false
+        return bitmap
+    }
+
+    /**
+     * Share the screenshot through social media
+     * @param bitmap
+     */
+    @SuppressLint("SetWorldReadable")
+    fun shareScreen(bitmap: Bitmap) {
+        try {
+            val file = File(this.externalCacheDir, "screen.png")
+            FileOutputStream(file).use { fOut ->
+                bitmap.compress(Bitmap.CompressFormat.PNG, 100, fOut)
+                fOut.flush()
+            }
+            file.setReadable(true, false)
+            val intent = Intent(Intent.ACTION_SEND).apply {
+                flags = Intent.FLAG_ACTIVITY_NEW_TASK
+                putExtra(Intent.EXTRA_STREAM, Uri.fromFile(file))
+                type = "image/png"
+            }
+            startActivity(Intent.createChooser(intent, getString(R.string.share_image_via)))
+        } catch (e: Exception) {
+            e.printStackTrace()
+        }
+    }
+
+    /**
+     * It displays the AlertDialog with Image of screenshot
+     * @param screenshot
+     */
+    fun showAlert(screenshot: Bitmap) {
+        val alertadd = AlertDialog.Builder(this)
+        val factory = LayoutInflater.from(this)
+        val view = factory.inflate(R.layout.image_alert_layout, null)
+        val screenShotImage = view.findViewById<ImageView>(R.id.alert_image)
+        screenShotImage.setImageBitmap(screenshot)
+        val shareMessage = view.findViewById<TextView>(R.id.alert_text)
+        shareMessage.setText(R.string.quiz_result_share_message)
+        alertadd.setView(view)
+        alertadd.setPositiveButton(R.string.about_translate_proceed) { dialog, _ ->
+            shareScreen(screenshot)
+        }
+        alertadd.setNegativeButton(android.R.string.cancel) { dialog, _ ->
+            dialog.cancel()
+        }
+        alertadd.show()
+    }
+}

app/src/main/java/fr/free/nrw/commons/quiz/RadioGroupHelper.java

@@ -1,64 +0,0 @@
-package fr.free.nrw.commons.quiz;
-
-import android.app.Activity;
-import android.view.View;
-import android.widget.CompoundButton;
-import android.widget.RadioButton;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Used to group to or more radio buttons to ensure
- * that at a particular time only one of them is selected
- */
-public class RadioGroupHelper {
-
-    public List<CompoundButton> radioButtons = new ArrayList<>();
-
-    /**
-     * Constructor to group radio buttons
-     * @param radios
-     */
-    public RadioGroupHelper(RadioButton... radios) {
-        super();
-        for (RadioButton rb : radios) {
-            add(rb);
-        }
-    }
-
-    /**
-     * Constructor to group radio buttons
-     * @param activity
-     * @param radiosIDs
-     */
-    public RadioGroupHelper(Activity activity, int... radiosIDs) {
-        this(activity.findViewById(android.R.id.content),radiosIDs);
-    }
-
-    /**
-     * Constructor to group radio buttons
-     * @param rootView
-     * @param radiosIDs
-     */
-    public RadioGroupHelper(View rootView, int... radiosIDs) {
-        super();
-        for (int radioButtonID : radiosIDs) {
-            add(rootView.findViewById(radioButtonID));
-        }
-    }
-
-    private void add(CompoundButton button){
-        this.radioButtons.add(button);
-        button.setOnClickListener(onClickListener);
-    }
-
-    /**
-     * listener to ensure only one of the radio button is selected
-     */
-    View.OnClickListener onClickListener = v -> {
-        for (CompoundButton rb : radioButtons) {
-            if (rb != v) rb.setChecked(false);
-        }
-    };
-}

app/src/main/java/fr/free/nrw/commons/quiz/RadioGroupHelper.kt

@@ -0,0 +1,61 @@
+package fr.free.nrw.commons.quiz
+
+import android.app.Activity
+import android.view.View
+import android.widget.CompoundButton
+import android.widget.RadioButton
+
+import java.util.ArrayList
+
+/**
+ * Used to group to or more radio buttons to ensure
+ * that at a particular time only one of them is selected
+ */
+class RadioGroupHelper {
+
+    val radioButtons: MutableList<CompoundButton> = ArrayList()
+
+    /**
+     * Constructor to group radio buttons
+     * @param radios
+     */
+    constructor(vararg radios: RadioButton) {
+        for (rb in radios) {
+            add(rb)
+        }
+    }
+
+    /**
+     * Constructor to group radio buttons
+     * @param activity
+     * @param radiosIDs
+     */
+    constructor(activity: Activity, vararg radiosIDs: Int) : this(
+        *radiosIDs.map { id -> activity.findViewById<RadioButton>(id) }.toTypedArray()
+    )
+
+    /**
+     * Constructor to group radio buttons
+     * @param rootView
+     * @param radiosIDs
+     */
+    constructor(rootView: View, vararg radiosIDs: Int) {
+        for (radioButtonID in radiosIDs) {
+            add(rootView.findViewById(radioButtonID))
+        }
+    }
+
+    private fun add(button: CompoundButton) {
+        radioButtons.add(button)
+        button.setOnClickListener(onClickListener)
+    }
+
+    /**
+     * listener to ensure only one of the radio button is selected
+     */
+    private val onClickListener = View.OnClickListener { v ->
+        for (rb in radioButtons) {
+            if (rb != v) rb.isChecked = false
+        }
+    }
+}

app/src/main/java/fr/free/nrw/commons/recentlanguages/RecentLanguagesContentProvider.java

@@ -1,122 +0,0 @@
-package fr.free.nrw.commons.recentlanguages;
-
-import static fr.free.nrw.commons.recentlanguages.RecentLanguagesDao.Table.COLUMN_NAME;
-import static fr.free.nrw.commons.recentlanguages.RecentLanguagesDao.Table.TABLE_NAME;
-
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteQueryBuilder;
-import android.net.Uri;
-import android.text.TextUtils;
-import androidx.annotation.NonNull;
-import fr.free.nrw.commons.BuildConfig;
-import fr.free.nrw.commons.data.DBOpenHelper;
-import fr.free.nrw.commons.di.CommonsDaggerContentProvider;
-import javax.inject.Inject;
-import timber.log.Timber;
-
-/**
- * Content provider of recently used languages
- */
-public class RecentLanguagesContentProvider extends CommonsDaggerContentProvider {
-
-    private static final String BASE_PATH = "recent_languages";
-    public static final Uri BASE_URI =
-        Uri.parse("content://" + BuildConfig.RECENT_LANGUAGE_AUTHORITY + "/" + BASE_PATH);
-
-
-    /**
-     * Append language code to the base uri
-     * @param languageCode Code of a language
-     */
-    public static Uri uriForCode(final String languageCode) {
-        return Uri.parse(BASE_URI + "/" + languageCode);
-    }
-
-    @Inject
-    DBOpenHelper dbOpenHelper;
-
-    @Override
-    public String getType(@NonNull final Uri uri) {
-        return null;
-    }
-
-    /**
-     * Queries the SQLite database for the recently used languages
-     * @param uri : contains the uri for recently used languages
-     * @param projection : contains the all fields of the table
-     * @param selection : handles Where
-     * @param selectionArgs : the condition of Where clause
-     * @param sortOrder : ascending or descending
-     */
-    @Override
-    public Cursor query(@NonNull final Uri uri, final String[] projection, final String selection,
-        final String[] selectionArgs, final String sortOrder) {
-        final SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
-        queryBuilder.setTables(TABLE_NAME);
-        final SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
-        final Cursor cursor = queryBuilder.query(db, projection, selection,
-            selectionArgs, null, null, sortOrder);
-        cursor.setNotificationUri(getContext().getContentResolver(), uri);
-        return cursor;
-    }
-
-    /**
-     * Handles the update query of local SQLite Database
-     * @param uri : contains the uri for recently used languages
-     * @param contentValues : new values to be entered to db
-     * @param selection : handles Where
-     * @param selectionArgs : the condition of Where clause
-     */
-    @Override
-    public int update(@NonNull final Uri uri, final ContentValues contentValues,
-        final String selection, final String[] selectionArgs) {
-        final SQLiteDatabase sqlDB = dbOpenHelper.getWritableDatabase();
-        final int rowsUpdated;
-        if (TextUtils.isEmpty(selection)) {
-            final int id = Integer.parseInt(uri.getLastPathSegment());
-            rowsUpdated = sqlDB.update(TABLE_NAME,
-                contentValues,
-                COLUMN_NAME + " = ?",
-                new String[]{String.valueOf(id)});
-        } else {
-            throw new IllegalArgumentException(
-                "Parameter `selection` should be empty when updating an ID");
-        }
-
-        getContext().getContentResolver().notifyChange(uri, null);
-        return rowsUpdated;
-    }
-
-    /**
-     * Handles the insertion of new recently used languages record to local SQLite Database
-     * @param uri : contains the uri for recently used languages
-     * @param contentValues : new values to be entered to db
-     */
-    @Override
-    public Uri insert(@NonNull final Uri uri, final ContentValues contentValues) {
-        final SQLiteDatabase sqlDB = dbOpenHelper.getWritableDatabase();
-        final long id = sqlDB.insert(TABLE_NAME, null, contentValues);
-        getContext().getContentResolver().notifyChange(uri, null);
-        return Uri.parse(BASE_URI + "/" + id);
-    }
-
-    /**
-     * Handles the deletion of new recently used languages record to local SQLite Database
-     * @param uri : contains the uri for recently used languages
-     */
-    @Override
-    public int delete(@NonNull final Uri uri, final String s, final String[] strings) {
-        final int rows;
-        final SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
-        Timber.d("Deleting recently used language %s", uri.getLastPathSegment());
-        rows = db.delete(
-            TABLE_NAME,
-            "language_code = ?",
-            new String[]{uri.getLastPathSegment()}
-        );
-        getContext().getContentResolver().notifyChange(uri, null);
-        return rows;
-    }
-}

app/src/main/java/fr/free/nrw/commons/recentlanguages/RecentLanguagesContentProvider.kt

@@ -0,0 +1,142 @@
+package fr.free.nrw.commons.recentlanguages
+
+
+import android.content.ContentValues
+import android.database.Cursor
+import android.database.sqlite.SQLiteDatabase
+import android.database.sqlite.SQLiteQueryBuilder
+import android.net.Uri
+import android.text.TextUtils
+import fr.free.nrw.commons.BuildConfig
+import fr.free.nrw.commons.data.DBOpenHelper
+import fr.free.nrw.commons.di.CommonsDaggerContentProvider
+import fr.free.nrw.commons.recentlanguages.RecentLanguagesDao.Table.COLUMN_NAME
+import fr.free.nrw.commons.recentlanguages.RecentLanguagesDao.Table.TABLE_NAME
+import javax.inject.Inject
+import timber.log.Timber
+
+
+/**
+ * Content provider of recently used languages
+ */
+class RecentLanguagesContentProvider : CommonsDaggerContentProvider() {
+
+    companion object {
+        private const val BASE_PATH = "recent_languages"
+        val BASE_URI: Uri =
+            Uri.parse(
+                "content://${BuildConfig.RECENT_LANGUAGE_AUTHORITY}/$BASE_PATH"
+            )
+
+        /**
+         * Append language code to the base URI
+         * @param languageCode Code of a language
+         */
+        @JvmStatic
+        fun uriForCode(languageCode: String): Uri {
+            return Uri.parse("$BASE_URI/$languageCode")
+        }
+    }
+
+    @Inject
+    lateinit var dbOpenHelper: DBOpenHelper
+
+    override fun getType(uri: Uri): String? {
+        return null
+    }
+
+    /**
+     * Queries the SQLite database for the recently used languages
+     * @param uri : contains the URI for recently used languages
+     * @param projection : contains all fields of the table
+     * @param selection : handles WHERE
+     * @param selectionArgs : the condition of WHERE clause
+     * @param sortOrder : ascending or descending
+     */
+    override fun query(
+        uri: Uri,
+        projection: Array<String>?,
+        selection: String?,
+        selectionArgs: Array<String>?,
+        sortOrder: String?
+    ): Cursor? {
+        val queryBuilder = SQLiteQueryBuilder()
+        queryBuilder.tables = TABLE_NAME
+        val db = dbOpenHelper.readableDatabase
+        val cursor = queryBuilder.query(
+            db,
+            projection,
+            selection,
+            selectionArgs,
+            null,
+            null,
+            sortOrder
+        )
+        cursor.setNotificationUri(context?.contentResolver, uri)
+        return cursor
+    }
+
+    /**
+     * Handles the update query of local SQLite Database
+     * @param uri : contains the URI for recently used languages
+     * @param contentValues : new values to be entered to the database
+     * @param selection : handles WHERE
+     * @param selectionArgs : the condition of WHERE clause
+     */
+    override fun update(
+        uri: Uri,
+        contentValues: ContentValues?,
+        selection: String?,
+        selectionArgs: Array<String>?
+    ): Int {
+        val sqlDB = dbOpenHelper.writableDatabase
+        val rowsUpdated: Int
+        if (selection.isNullOrEmpty()) {
+            val id = uri.lastPathSegment?.toInt()
+                ?: throw IllegalArgumentException("Invalid URI: $uri")
+            rowsUpdated = sqlDB.update(
+                TABLE_NAME,
+                contentValues,
+                "$COLUMN_NAME = ?",
+                arrayOf(id.toString())
+            )
+        } else {
+            throw IllegalArgumentException("Parameter `selection` should be empty when updating an ID")
+        }
+
+        context?.contentResolver?.notifyChange(uri, null)
+        return rowsUpdated
+    }
+
+    /**
+     * Handles the insertion of new recently used languages record to local SQLite Database
+     * @param uri : contains the URI for recently used languages
+     * @param contentValues : new values to be entered to the database
+     */
+    override fun insert(uri: Uri, contentValues: ContentValues?): Uri? {
+        val sqlDB = dbOpenHelper.writableDatabase
+        val id = sqlDB.insert(
+            TABLE_NAME,
+            null,
+            contentValues
+        )
+        context?.contentResolver?.notifyChange(uri, null)
+        return Uri.parse("$BASE_URI/$id")
+    }
+
+    /**
+     * Handles the deletion of a recently used languages record from local SQLite Database
+     * @param uri : contains the URI for recently used languages
+     */
+    override fun delete(uri: Uri, s: String?, strings: Array<String>?): Int {
+        val db = dbOpenHelper.readableDatabase
+        Timber.d("Deleting recently used language %s", uri.lastPathSegment)
+        val rows = db.delete(
+            TABLE_NAME,
+            "language_code = ?",
+            arrayOf(uri.lastPathSegment)
+        )
+        context?.contentResolver?.notifyChange(uri, null)
+        return rows
+    }
+}

app/src/main/java/fr/free/nrw/commons/recentlanguages/RecentLanguagesDao.java

@@ -1,204 +0,0 @@
-package fr.free.nrw.commons.recentlanguages;
-
-import android.annotation.SuppressLint;
-import android.content.ContentProviderClient;
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.database.sqlite.SQLiteDatabase;
-import android.os.RemoteException;
-import androidx.annotation.NonNull;
-import java.util.ArrayList;
-import java.util.List;
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Provider;
-import javax.inject.Singleton;
-
-/**
- * Handles database operations for recently used languages
- */
-@Singleton
-public class RecentLanguagesDao {
-
-    private final Provider<ContentProviderClient> clientProvider;
-
-    @Inject
-    public RecentLanguagesDao
-        (@Named("recent_languages") final Provider<ContentProviderClient> clientProvider) {
-        this.clientProvider = clientProvider;
-    }
-
-    /**
-     * Find all persisted recently used languages on database
-     * @return list of recently used languages
-     */
-    public List<Language> getRecentLanguages() {
-        final List<Language> languages = new ArrayList<>();
-        final ContentProviderClient db = clientProvider.get();
-        try (final Cursor cursor = db.query(
-            RecentLanguagesContentProvider.BASE_URI,
-            RecentLanguagesDao.Table.ALL_FIELDS,
-            null,
-            new String[]{},
-            null)) {
-            if(cursor != null && cursor.moveToLast()) {
-                do {
-                    languages.add(fromCursor(cursor));
-                } while (cursor.moveToPrevious());
-            }
-        } catch (final RemoteException e) {
-            throw new RuntimeException(e);
-        } finally {
-            db.release();
-        }
-        return languages;
-    }
-
-    /**
-     * Add a Language to database
-     * @param language : Language to add
-     */
-    public void addRecentLanguage(final Language language) {
-        final ContentProviderClient db = clientProvider.get();
-        try {
-            db.insert(RecentLanguagesContentProvider.BASE_URI, toContentValues(language));
-        } catch (final RemoteException e) {
-            throw new RuntimeException(e);
-        } finally {
-            db.release();
-        }
-    }
-
-    /**
-     * Delete a language from database
-     * @param languageCode : code of the Language to delete
-     */
-    public void deleteRecentLanguage(final String languageCode) {
-        final ContentProviderClient db = clientProvider.get();
-        try {
-            db.delete(RecentLanguagesContentProvider.uriForCode(languageCode), null, null);
-        } catch (final RemoteException e) {
-            throw new RuntimeException(e);
-        } finally {
-            db.release();
-        }
-    }
-
-    /**
-     * Find a language from database based on its name
-     * @param languageCode : code of the Language to find
-     * @return boolean : is language in database ?
-     */
-    public boolean findRecentLanguage(final String languageCode) {
-        if (languageCode == null) { //Avoiding NPE's
-            return false;
-        }
-        final ContentProviderClient db = clientProvider.get();
-        try (final Cursor cursor = db.query(
-            RecentLanguagesContentProvider.BASE_URI,
-            RecentLanguagesDao.Table.ALL_FIELDS,
-            Table.COLUMN_CODE + "=?",
-            new String[]{languageCode},
-            null
-        )) {
-            if (cursor != null && cursor.moveToFirst()) {
-                return true;
-            }
-        } catch (final RemoteException e) {
-            throw new RuntimeException(e);
-        } finally {
-            db.release();
-        }
-        return false;
-    }
-
-    /**
-     * It creates an Recent Language object from data stored in the SQLite DB by using cursor
-     * @param cursor cursor
-     * @return Language object
-     */
-    @NonNull
-    @SuppressLint("Range")
-    Language fromCursor(final Cursor cursor) {
-        // Hardcoding column positions!
-        final String languageName = cursor.getString(cursor.getColumnIndex(Table.COLUMN_NAME));
-        final String languageCode = cursor.getString(cursor.getColumnIndex(Table.COLUMN_CODE));
-        return new Language(languageName, languageCode);
-    }
-
-    /**
-     * Takes data from Language and create a content value object
-     * @param recentLanguage recently used language
-     * @return ContentValues
-     */
-    private ContentValues toContentValues(final Language recentLanguage) {
-        final ContentValues cv = new ContentValues();
-        cv.put(Table.COLUMN_NAME, recentLanguage.getLanguageName());
-        cv.put(Table.COLUMN_CODE, recentLanguage.getLanguageCode());
-        return cv;
-    }
-
-    /**
-     * This class contains the database table architecture for recently used languages,
-     * It also contains queries and logic necessary to the create, update, delete this table.
-     */
-    public static final class Table {
-        public static final String TABLE_NAME = "recent_languages";
-        static final String COLUMN_NAME = "language_name";
-        static final String COLUMN_CODE = "language_code";
-
-        // NOTE! KEEP IN SAME ORDER AS THEY ARE DEFINED UP THERE. HELPS HARD CODE COLUMN INDICES.
-        public static final String[] ALL_FIELDS = {
-            COLUMN_NAME,
-            COLUMN_CODE
-        };
-
-        static final String DROP_TABLE_STATEMENT = "DROP TABLE IF EXISTS " + TABLE_NAME;
-
-        static final String CREATE_TABLE_STATEMENT = "CREATE TABLE " + TABLE_NAME + " ("
-            + COLUMN_NAME + " STRING,"
-            + COLUMN_CODE + " STRING PRIMARY KEY"
-            + ");";
-
-        /**
-         * This method creates a LanguagesTable in SQLiteDatabase
-         * @param db SQLiteDatabase
-         */
-        public static void onCreate(final SQLiteDatabase db) {
-            db.execSQL(CREATE_TABLE_STATEMENT);
-        }
-
-        /**
-         * This method deletes LanguagesTable from SQLiteDatabase
-         * @param db SQLiteDatabase
-         */
-        public static void onDelete(final SQLiteDatabase db) {
-            db.execSQL(DROP_TABLE_STATEMENT);
-            onCreate(db);
-        }
-
-        /**
-         * This method is called on migrating from a older version to a newer version
-         * @param db SQLiteDatabase
-         * @param from Version from which we are migrating
-         * @param to Version to which we are migrating
-         */
-        public static void onUpdate(final SQLiteDatabase db, int from, final int to) {
-            if (from == to) {
-                return;
-            }
-            if (from < 19) {
-                // doesn't exist yet
-                from++;
-                onUpdate(db, from, to);
-                return;
-            }
-            if (from == 19) {
-                // table added in version 20
-                onCreate(db);
-                from++;
-                onUpdate(db, from, to);
-            }
-        }
-    }
-}

app/src/main/java/fr/free/nrw/commons/recentlanguages/RecentLanguagesDao.kt

@@ -0,0 +1,215 @@
+package fr.free.nrw.commons.recentlanguages
+
+import android.annotation.SuppressLint
+import android.content.ContentProviderClient
+import android.content.ContentValues
+import android.database.Cursor
+import android.database.sqlite.SQLiteDatabase
+import android.os.RemoteException
+import javax.inject.Inject
+import javax.inject.Named
+import javax.inject.Provider
+import javax.inject.Singleton
+
+
+/**
+ * Handles database operations for recently used languages
+ */
+@Singleton
+class RecentLanguagesDao @Inject constructor(
+    @Named("recent_languages")
+    private val clientProvider: Provider<ContentProviderClient>
+) {
+
+    /**
+     * Find all persisted recently used languages on database
+     * @return list of recently used languages
+     */
+    fun getRecentLanguages(): List<Language> {
+        val languages = mutableListOf<Language>()
+        val db = clientProvider.get()
+        try {
+            db.query(
+                RecentLanguagesContentProvider.BASE_URI,
+                Table.ALL_FIELDS,
+                null,
+                arrayOf(),
+                null
+            )?.use { cursor ->
+                if (cursor.moveToLast()) {
+                    do {
+                        languages.add(fromCursor(cursor))
+                    } while (cursor.moveToPrevious())
+                }
+            }
+        } catch (e: RemoteException) {
+            throw RuntimeException(e)
+        } finally {
+            db.release()
+        }
+        return languages
+    }
+
+    /**
+     * Add a Language to database
+     * @param language : Language to add
+     */
+    fun addRecentLanguage(language: Language) {
+        val db = clientProvider.get()
+        try {
+            db.insert(
+                RecentLanguagesContentProvider.BASE_URI,
+                toContentValues(language)
+            )
+        } catch (e: RemoteException) {
+            throw RuntimeException(e)
+        } finally {
+            db.release()
+        }
+    }
+
+    /**
+     * Delete a language from database
+     * @param languageCode : code of the Language to delete
+     */
+    fun deleteRecentLanguage(languageCode: String) {
+        val db = clientProvider.get()
+        try {
+            db.delete(
+                RecentLanguagesContentProvider.uriForCode(languageCode),
+                null,
+                null
+            )
+        } catch (e: RemoteException) {
+            throw RuntimeException(e)
+        } finally {
+            db.release()
+        }
+    }
+
+    /**
+     * Find a language from database based on its name
+     * @param languageCode : code of the Language to find
+     * @return boolean : is language in database ?
+     */
+    fun findRecentLanguage(languageCode: String?): Boolean {
+        if (languageCode == null) { // Avoiding NPEs
+            return false
+        }
+        val db = clientProvider.get()
+        try {
+            db.query(
+                RecentLanguagesContentProvider.BASE_URI,
+                Table.ALL_FIELDS,
+                "${Table.COLUMN_CODE}=?",
+                arrayOf(languageCode),
+                null
+            )?.use { cursor ->
+                if (cursor.moveToFirst()) {
+                    return true
+                }
+            }
+        } catch (e: RemoteException) {
+            throw RuntimeException(e)
+        } finally {
+            db.release()
+        }
+        return false
+    }
+
+    /**
+     * It creates an Recent Language object from data stored in the SQLite DB by using cursor
+     * @param cursor cursor
+     * @return Language object
+     */
+    @SuppressLint("Range")
+    fun fromCursor(cursor: Cursor): Language {
+        // Hardcoding column positions!
+        val languageName = cursor.getString(
+            cursor.getColumnIndex(Table.COLUMN_NAME)
+        )
+        val languageCode = cursor.getString(
+            cursor.getColumnIndex(Table.COLUMN_CODE)
+        )
+        return Language(languageName, languageCode)
+    }
+
+    /**
+     * Takes data from Language and create a content value object
+     * @param recentLanguage recently used language
+     * @return ContentValues
+     */
+    private fun toContentValues(recentLanguage: Language): ContentValues {
+        return ContentValues().apply {
+            put(Table.COLUMN_NAME, recentLanguage.languageName)
+            put(Table.COLUMN_CODE, recentLanguage.languageCode)
+        }
+    }
+
+    /**
+     * This class contains the database table architecture for recently used languages,
+     * It also contains queries and logic necessary to the create, update, delete this table.
+     */
+    object Table {
+        const val TABLE_NAME = "recent_languages"
+        const val COLUMN_NAME = "language_name"
+        const val COLUMN_CODE = "language_code"
+
+        // NOTE! KEEP IN SAME ORDER AS THEY ARE DEFINED UP THERE. HELPS HARD CODE COLUMN INDICES.
+        @JvmStatic
+        val ALL_FIELDS = arrayOf(
+            COLUMN_NAME,
+            COLUMN_CODE
+        )
+
+        const val DROP_TABLE_STATEMENT = "DROP TABLE IF EXISTS $TABLE_NAME"
+
+        const val CREATE_TABLE_STATEMENT = "CREATE TABLE $TABLE_NAME (" +
+                "$COLUMN_NAME STRING," +
+                "$COLUMN_CODE STRING PRIMARY KEY" +
+                ");"
+
+        /**
+         * This method creates a LanguagesTable in SQLiteDatabase
+         * @param db SQLiteDatabase
+         */
+        @SuppressLint("SQLiteString")
+        @JvmStatic
+        fun onCreate(db: SQLiteDatabase) {
+            db.execSQL(CREATE_TABLE_STATEMENT)
+        }
+
+        /**
+         * This method deletes LanguagesTable from SQLiteDatabase
+         * @param db SQLiteDatabase
+         */
+        @JvmStatic
+        fun onDelete(db: SQLiteDatabase) {
+            db.execSQL(DROP_TABLE_STATEMENT)
+            onCreate(db)
+        }
+
+        /**
+         * This method is called on migrating from a older version to a newer version
+         * @param db SQLiteDatabase
+         * @param from Version from which we are migrating
+         * @param to Version to which we are migrating
+         */
+        @JvmStatic
+        fun onUpdate(db: SQLiteDatabase, from: Int, to: Int) {
+            if (from == to) {
+                return
+            }
+            if (from < 19) {
+                // doesn't exist yet
+                onUpdate(db, from + 1, to)
+                return
+            }
+            if (from == 19) {
+                // table added in version 20
+                onCreate(db)
+                onUpdate(db, from + 1, to)
+            }
+        }
+    }
+}

app/src/main/java/fr/free/nrw/commons/repository/UploadRepository.java

@@ -1,423 +0,0 @@
-package fr.free.nrw.commons.repository;
-
-import androidx.annotation.Nullable;
-import fr.free.nrw.commons.Media;
-import fr.free.nrw.commons.category.CategoriesModel;
-import fr.free.nrw.commons.category.CategoryItem;
-import fr.free.nrw.commons.contributions.Contribution;
-import fr.free.nrw.commons.contributions.ContributionDao;
-import fr.free.nrw.commons.filepicker.UploadableFile;
-import fr.free.nrw.commons.location.LatLng;
-import fr.free.nrw.commons.nearby.NearbyPlaces;
-import fr.free.nrw.commons.nearby.Place;
-import fr.free.nrw.commons.upload.ImageCoordinates;
-import fr.free.nrw.commons.upload.SimilarImageInterface;
-import fr.free.nrw.commons.upload.UploadController;
-import fr.free.nrw.commons.upload.UploadItem;
-import fr.free.nrw.commons.upload.UploadModel;
-import fr.free.nrw.commons.upload.structure.depictions.DepictModel;
-import fr.free.nrw.commons.upload.structure.depictions.DepictedItem;
-import io.reactivex.Flowable;
-import io.reactivex.Observable;
-import io.reactivex.Single;
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Locale;
-import java.util.Set;
-import javax.inject.Inject;
-import javax.inject.Singleton;
-import timber.log.Timber;
-
-/**
- * The repository class for UploadActivity
- */
-@Singleton
-public class UploadRepository {
-
-    private final UploadModel uploadModel;
-    private final UploadController uploadController;
-    private final CategoriesModel categoriesModel;
-    private final NearbyPlaces nearbyPlaces;
-    private final DepictModel depictModel;
-
-    private static final double NEARBY_RADIUS_IN_KILO_METERS = 0.1; //100 meters
-    private final ContributionDao contributionDao;
-
-    @Inject
-    public UploadRepository(UploadModel uploadModel,
-        UploadController uploadController,
-        CategoriesModel categoriesModel,
-        NearbyPlaces nearbyPlaces,
-        DepictModel depictModel,
-        ContributionDao contributionDao) {
-        this.uploadModel = uploadModel;
-        this.uploadController = uploadController;
-        this.categoriesModel = categoriesModel;
-        this.nearbyPlaces = nearbyPlaces;
-        this.depictModel = depictModel;
-        this.contributionDao=contributionDao;
-    }
-
-    /**
-     * asks the RemoteDataSource to build contributions
-     *
-     * @return
-     */
-    public Observable<Contribution> buildContributions() {
-        return uploadModel.buildContributions();
-    }
-
-    /**
-     * asks the RemoteDataSource to start upload for the contribution
-     *
-     * @param contribution
-     */
-
-    public void prepareMedia(Contribution contribution) {
-        uploadController.prepareMedia(contribution);
-    }
-
-
-    public void saveContribution(Contribution contribution) {
-        contributionDao.save(contribution).blockingAwait();
-    }
-
-    /**
-     * Fetches and returns all the Upload Items
-     *
-     * @return
-     */
-    public List<UploadItem> getUploads() {
-        return uploadModel.getUploads();
-    }
-
-    /**
-     *Prepare for a fresh upload
-     */
-    public void cleanup() {
-        uploadModel.cleanUp();
-        //This needs further refactoring, this should not be here, right now the structure wont suppoort rhis
-        categoriesModel.cleanUp();
-        depictModel.cleanUp();
-    }
-
-    /**
-     * Fetches and returns the selected categories for the current upload
-     *
-     * @return
-     */
-    public List<CategoryItem> getSelectedCategories() {
-        return categoriesModel.getSelectedCategories();
-    }
-
-    /**
-     * all categories from MWApi
-     *
-     * @param query
-     * @param imageTitleList
-     * @param selectedDepictions
-     * @return
-     */
-    public Observable<List<CategoryItem>> searchAll(String query, List<String> imageTitleList,
-        List<DepictedItem> selectedDepictions) {
-        return categoriesModel.searchAll(query, imageTitleList, selectedDepictions);
-    }
-
-    /**
-     * sets the list of selected categories for the current upload
-     *
-     * @param categoryStringList
-     */
-    public void setSelectedCategories(List<String> categoryStringList) {
-        uploadModel.setSelectedCategories(categoryStringList);
-    }
-
-    /**
-     * handles the category selection/deselection
-     *
-     * @param categoryItem
-     */
-    public void onCategoryClicked(CategoryItem categoryItem, final Media media) {
-        categoriesModel.onCategoryItemClicked(categoryItem, media);
-    }
-
-    /**
-     * prunes the category list for irrelevant categories see #750
-     *
-     * @param name
-     * @return
-     */
-    public boolean isSpammyCategory(String name) {
-        return categoriesModel.isSpammyCategory(name);
-    }
-
-    /**
-     * retursn the string list of available license from the LocalDataSource
-     *
-     * @return
-     */
-    public List<String> getLicenses() {
-        return uploadModel.getLicenses();
-    }
-
-    /**
-     * returns the selected license for the current upload
-     *
-     * @return
-     */
-    public String getSelectedLicense() {
-        return uploadModel.getSelectedLicense();
-    }
-
-    /**
-     * returns the number of Upload Items
-     *
-     * @return
-     */
-    public int getCount() {
-        return uploadModel.getCount();
-    }
-
-    /**
-     * ask the RemoteDataSource to pre process the image
-     *
-     * @param uploadableFile
-     * @param place
-     * @param similarImageInterface
-     * @return
-     */
-    public Observable<UploadItem> preProcessImage(UploadableFile uploadableFile, Place place,
-        SimilarImageInterface similarImageInterface, LatLng inAppPictureLocation) {
-        return uploadModel.preProcessImage(uploadableFile, place,
-            similarImageInterface, inAppPictureLocation);
-    }
-
-    /**
-     * query the RemoteDataSource for image quality
-     *
-     * @param uploadItem UploadItem whose caption is to be checked
-     * @return Quality of UploadItem
-     */
-    public Single<Integer> getImageQuality(UploadItem uploadItem, LatLng location) {
-        return uploadModel.getImageQuality(uploadItem, location);
-    }
-
-    /**
-     * query the RemoteDataSource for image duplicity check
-     *
-     * @param filePath file to be checked
-     * @return IMAGE_DUPLICATE or IMAGE_OK
-     */
-    public Single<Integer> checkDuplicateImage(String filePath) {
-        return uploadModel.checkDuplicateImage(filePath);
-    }
-
-    /**
-     * query the RemoteDataSource for caption quality
-     *
-     * @param uploadItem UploadItem whose caption is to be checked
-     * @return Quality of caption of the UploadItem
-     */
-    public Single<Integer> getCaptionQuality(UploadItem uploadItem) {
-        return uploadModel.getCaptionQuality(uploadItem);
-    }
-
-    /**
-     * asks the LocalDataSource to delete the file with the given file path
-     *
-     * @param filePath
-     */
-    public void deletePicture(String filePath) {
-        uploadModel.deletePicture(filePath);
-    }
-
-    /**
-     * fetches and returns the upload item
-     *
-     * @param index
-     * @return
-     */
-    public UploadItem getUploadItem(int index) {
-        if (index >= 0) {
-            return uploadModel.getItems().get(index);
-        }
-        return null; //There is no item to copy details
-    }
-
-    /**
-     * set selected license for the current upload
-     *
-     * @param licenseName
-     */
-    public void setSelectedLicense(String licenseName) {
-        uploadModel.setSelectedLicense(licenseName);
-    }
-
-    public void onDepictItemClicked(DepictedItem depictedItem, final Media media) {
-        uploadModel.onDepictItemClicked(depictedItem, media);
-    }
-
-    /**
-     * Fetches and returns the selected depictions for the current upload
-     *
-     * @return
-     */
-
-    public List<DepictedItem> getSelectedDepictions() {
-        return uploadModel.getSelectedDepictions();
-    }
-
-    /**
-     * Provides selected existing depicts
-     *
-     * @return selected existing depicts
-     */
-    public List<String> getSelectedExistingDepictions() {
-        return uploadModel.getSelectedExistingDepictions();
-    }
-
-    /**
-     * Initialize existing depicts
-     *
-     * @param selectedExistingDepictions existing depicts
-     */
-    public void setSelectedExistingDepictions(final List<String> selectedExistingDepictions) {
-        uploadModel.setSelectedExistingDepictions(selectedExistingDepictions);
-    }
-    /**
-     * Search all depictions from
-     *
-     * @param query
-     * @return
-     */
-
-    public Flowable<List<DepictedItem>> searchAllEntities(String query) {
-        return depictModel.searchAllEntities(query, this);
-    }
-
-    /**
-     * Gets the depiction for each unique {@link Place} associated with an {@link UploadItem}
-     * from {@link #getUploads()}
-     *
-     * @return a single that provides the depictions
-     */
-    public Single<List<DepictedItem>> getPlaceDepictions() {
-        final Set<String> qids = new HashSet<>();
-        for (final UploadItem item : getUploads()) {
-            final Place place = item.getPlace();
-            if (place != null) {
-                qids.add(place.getWikiDataEntityId());
-            }
-        }
-        return depictModel.getPlaceDepictions(new ArrayList<>(qids));
-    }
-
-    /**
-     * Gets the category for each unique {@link Place} associated with an {@link UploadItem}
-     * from {@link #getUploads()}
-     *
-     * @return a single that provides the categories
-     */
-    public Single<List<CategoryItem>> getPlaceCategories() {
-        final Set<String> qids = new HashSet<>();
-        for (final UploadItem item : getUploads()) {
-            final Place place = item.getPlace();
-            if (place != null) {
-                qids.add(place.getCategory());
-            }
-        }
-        return Single.fromObservable(categoriesModel.getCategoriesByName(new ArrayList<>(qids)));
-    }
-
-    /**
-     * Takes depict IDs as a parameter, converts into a slash separated String and Gets DepictItem
-     * from the server
-     *
-     * @param depictionsQIDs IDs of Depiction
-     * @return Flowable<List<DepictedItem>>
-     */
-    public Flowable<List<DepictedItem>> getDepictions(final List<String> depictionsQIDs){
-        final String ids = joinQIDs(depictionsQIDs);
-        return depictModel.getDepictions(ids).toFlowable();
-    }
-
-    /**
-     * Builds a string by joining all IDs divided by "|"
-     *
-     * @param depictionsQIDs IDs of depiction ex. ["Q11023","Q1356"]
-     * @return string ex. "Q11023|Q1356"
-     */
-    private String joinQIDs(final List<String> depictionsQIDs) {
-        if (depictionsQIDs != null && !depictionsQIDs.isEmpty()) {
-            final StringBuilder buffer = new StringBuilder(depictionsQIDs.get(0));
-
-            if (depictionsQIDs.size() > 1) {
-                for (int i = 1; i < depictionsQIDs.size(); i++) {
-                    buffer.append("|");
-                    buffer.append(depictionsQIDs.get(i));
-                }
-            }
-            return buffer.toString();
-        }
-        return null;
-    }
-
-    /**
-     * Returns nearest place matching the passed latitude and longitude
-     *
-     * @param decLatitude
-     * @param decLongitude
-     * @return
-     */
-    @Nullable
-    public Place checkNearbyPlaces(final double decLatitude, final double decLongitude) {
-        try {
-            final List<Place> fromWikidataQuery = nearbyPlaces.getFromWikidataQuery(new LatLng(
-                    decLatitude, decLongitude, 0.0f),
-                Locale.getDefault().getLanguage(),
-                NEARBY_RADIUS_IN_KILO_METERS, null);
-            return (fromWikidataQuery != null && fromWikidataQuery.size() > 0) ? fromWikidataQuery
-                .get(0) : null;
-        } catch (final Exception e) {
-            Timber.e("Error fetching nearby places: %s", e.getMessage());
-            return null;
-        }
-    }
-
-    public void useSimilarPictureCoordinates(ImageCoordinates imageCoordinates, int uploadItemIndex) {
-        uploadModel.useSimilarPictureCoordinates(imageCoordinates, uploadItemIndex);
-    }
-
-    public boolean isWMLSupportedForThisPlace() {
-        return uploadModel.getItems().get(0).isWLMUpload();
-    }
-
-    /**
-     * Provides selected existing categories
-     *
-     * @return selected existing categories
-     */
-    public List<String> getSelectedExistingCategories() {
-        return categoriesModel.getSelectedExistingCategories();
-    }
-
-    /**
-     * Initialize existing categories
-     *
-     * @param selectedExistingCategories existing categories
-     */
-    public void setSelectedExistingCategories(final List<String> selectedExistingCategories) {
-        categoriesModel.setSelectedExistingCategories(selectedExistingCategories);
-    }
-
-    /**
-     * Takes category names and Gets CategoryItem from the server
-     *
-     * @param categories names of Category
-     * @return Observable<List<CategoryItem>>
-     */
-    public Observable<List<CategoryItem>> getCategories(final List<String> categories){
-        return categoriesModel.getCategoriesByName(categories);
-    }
-}

app/src/main/java/fr/free/nrw/commons/repository/UploadRepository.kt

@@ -0,0 +1,410 @@
+package fr.free.nrw.commons.repository
+
+import fr.free.nrw.commons.Media
+import fr.free.nrw.commons.category.CategoriesModel
+import fr.free.nrw.commons.category.CategoryItem
+import fr.free.nrw.commons.contributions.Contribution
+import fr.free.nrw.commons.contributions.ContributionDao
+import fr.free.nrw.commons.filepicker.UploadableFile
+import fr.free.nrw.commons.location.LatLng
+import fr.free.nrw.commons.nearby.NearbyPlaces
+import fr.free.nrw.commons.nearby.Place
+import fr.free.nrw.commons.upload.ImageCoordinates
+import fr.free.nrw.commons.upload.SimilarImageInterface
+import fr.free.nrw.commons.upload.UploadController
+import fr.free.nrw.commons.upload.UploadItem
+import fr.free.nrw.commons.upload.UploadModel
+import fr.free.nrw.commons.upload.structure.depictions.DepictModel
+import fr.free.nrw.commons.upload.structure.depictions.DepictedItem
+import io.reactivex.Flowable
+import io.reactivex.Observable
+import io.reactivex.Single
+import timber.log.Timber
+import java.util.Locale
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * The repository class for UploadActivity
+ */
+@Singleton
+class UploadRepository @Inject constructor(
+    private val uploadModel: UploadModel,
+    private val uploadController: UploadController,
+    private val categoriesModel: CategoriesModel,
+    private val nearbyPlaces: NearbyPlaces,
+    private val depictModel: DepictModel,
+    private val contributionDao: ContributionDao
+) {
+
+    companion object {
+        private const val NEARBY_RADIUS_IN_KILO_METERS = 0.1 // 100 meters
+    }
+
+    /**
+     * Asks the RemoteDataSource to build contributions
+     *
+     * @return
+     */
+    fun buildContributions(): Observable<Contribution>? {
+        return uploadModel.buildContributions()
+    }
+
+    /**
+     * Asks the RemoteDataSource to start upload for the contribution
+     *
+     * @param contribution
+     */
+    fun prepareMedia(contribution: Contribution) {
+        uploadController.prepareMedia(contribution)
+    }
+
+    fun saveContribution(contribution: Contribution) {
+        contributionDao.save(contribution).blockingAwait()
+    }
+
+    /**
+     * Fetches and returns all the Upload Items
+     *
+     * @return
+     */
+    fun getUploads(): List<UploadItem> {
+        return uploadModel.getUploads()
+    }
+
+    /**
+     * Prepare for a fresh upload
+     */
+    fun cleanup() {
+        uploadModel.cleanUp()
+        // This needs further refactoring, this should not be here, right now the structure
+        // won't support this
+        categoriesModel.cleanUp()
+        depictModel.cleanUp()
+    }
+
+    /**
+     * Fetches and returns the selected categories for the current upload
+     *
+     * @return
+     */
+    fun getSelectedCategories(): List<CategoryItem> {
+        return categoriesModel.getSelectedCategories()
+    }
+
+    /**
+     * All categories from MWApi
+     *
+     * @param query
+     * @param imageTitleList
+     * @param selectedDepictions
+     * @return
+     */
+    fun searchAll(
+        query: String,
+        imageTitleList: List<String>,
+        selectedDepictions: List<DepictedItem>
+    ): Observable<List<CategoryItem>> {
+        return categoriesModel.searchAll(query, imageTitleList, selectedDepictions)
+    }
+
+    /**
+     * Sets the list of selected categories for the current upload
+     *
+     * @param categoryStringList
+     */
+    fun setSelectedCategories(categoryStringList: List<String>) {
+        uploadModel.setSelectedCategories(categoryStringList)
+    }
+
+    /**
+     * Handles the category selection/deselection
+     *
+     * @param categoryItem
+     */
+    fun onCategoryClicked(categoryItem: CategoryItem, media: Media?) {
+        categoriesModel.onCategoryItemClicked(categoryItem, media)
+    }
+
+    /**
+     * Prunes the category list for irrelevant categories see #750
+     *
+     * @param name
+     * @return
+     */
+    fun isSpammyCategory(name: String): Boolean {
+        return categoriesModel.isSpammyCategory(name)
+    }
+
+    /**
+     * Returns the string list of available licenses from the LocalDataSource
+     *
+     * @return
+     */
+    fun getLicenses(): List<String> {
+        return uploadModel.licenses
+    }
+
+    /**
+     * Returns the selected license for the current upload
+     *
+     * @return
+     */
+    fun getSelectedLicense(): String? {
+        return uploadModel.selectedLicense
+    }
+
+    /**
+     * Returns the number of Upload Items
+     *
+     * @return
+     */
+    fun getCount(): Int {
+        return uploadModel.count
+    }
+
+    /**
+     * Ask the RemoteDataSource to preprocess the image
+     *
+     * @param uploadableFile
+     * @param place
+     * @param similarImageInterface
+     * @param inAppPictureLocation
+     * @return
+     */
+    fun preProcessImage(
+        uploadableFile: UploadableFile?,
+        place: Place?,
+        similarImageInterface: SimilarImageInterface?,
+        inAppPictureLocation: LatLng?
+    ): Observable<UploadItem>? {
+        return uploadModel.preProcessImage(
+            uploadableFile,
+            place,
+            similarImageInterface,
+            inAppPictureLocation
+        )
+    }
+
+    /**
+     * Query the RemoteDataSource for image quality
+     *
+     * @param uploadItem UploadItem whose caption is to be checked
+     * @param location Location of the image
+     * @return Quality of UploadItem
+     */
+    fun getImageQuality(uploadItem: UploadItem, location: LatLng?): Single<Int>? {
+        return uploadModel.getImageQuality(uploadItem, location)
+    }
+
+    /**
+     * Query the RemoteDataSource for image duplicity check
+     *
+     * @param filePath file to be checked
+     * @return IMAGE_DUPLICATE or IMAGE_OK
+     */
+    fun checkDuplicateImage(filePath: String): Single<Int> {
+        return uploadModel.checkDuplicateImage(filePath)
+    }
+
+    /**
+     * query the RemoteDataSource for caption quality
+     *
+     * @param uploadItem UploadItem whose caption is to be checked
+     * @return Quality of caption of the UploadItem
+     */
+    fun getCaptionQuality(uploadItem: UploadItem): Single<Int>? {
+        return uploadModel.getCaptionQuality(uploadItem)
+    }
+
+    /**
+     * asks the LocalDataSource to delete the file with the given file path
+     *
+     * @param filePath
+     */
+    fun deletePicture(filePath: String) {
+        uploadModel.deletePicture(filePath)
+    }
+
+    /**
+     * fetches and returns the upload item
+     *
+     * @param index
+     * @return
+     */
+    fun getUploadItem(index: Int): UploadItem? {
+        return if (index >= 0) {
+            uploadModel.items.getOrNull(index)
+        } else null //There is no item to copy details
+    }
+
+    /**
+     * set selected license for the current upload
+     *
+     * @param licenseName
+     */
+    fun setSelectedLicense(licenseName: String) {
+        uploadModel.selectedLicense = licenseName
+    }
+
+    fun onDepictItemClicked(depictedItem: DepictedItem, media: Media?) {
+        uploadModel.onDepictItemClicked(depictedItem, media)
+    }
+
+    /**
+     * Fetches and returns the selected depictions for the current upload
+     *
+     * @return
+     */
+    fun getSelectedDepictions(): List<DepictedItem> {
+        return uploadModel.selectedDepictions
+    }
+
+    /**
+     * Provides selected existing depicts
+     *
+     * @return selected existing depicts
+     */
+    fun getSelectedExistingDepictions(): List<String> {
+        return uploadModel.selectedExistingDepictions
+    }
+
+    /**
+     * Initialize existing depicts
+     *
+     * @param selectedExistingDepictions existing depicts
+     */
+    fun setSelectedExistingDepictions(selectedExistingDepictions: List<String>) {
+        uploadModel.selectedExistingDepictions = selectedExistingDepictions
+    }
+
+    /**
+     * Search all depictions from
+     *
+     * @param query
+     * @return
+     */
+    fun searchAllEntities(query: String): Flowable<List<DepictedItem>> {
+        return depictModel.searchAllEntities(query, this)
+    }
+
+    /**
+     * Gets the depiction for each unique {@link Place} associated with an {@link UploadItem}
+     * from {@link #getUploads()}
+     *
+     * @return a single that provides the depictions
+     */
+    fun getPlaceDepictions(): Single<List<DepictedItem>> {
+        val qids = mutableSetOf<String>()
+        getUploads().forEach { item ->
+            item.place?.let {
+                it.wikiDataEntityId?.let { it1 ->
+                    qids.add(it1)
+                }
+            }
+        }
+        return depictModel.getPlaceDepictions(qids.toList())
+    }
+
+    /**
+     * Gets the category for each unique {@link Place} associated with an {@link UploadItem}
+     * from {@link #getUploads()}
+     *
+     * @return a single that provides the categories
+     */
+    fun getPlaceCategories(): Single<List<CategoryItem>> {
+        val qids = mutableSetOf<String>()
+        getUploads().forEach { item ->
+            item.place?.category?.let { qids.add(it) }
+        }
+        return Single.fromObservable(categoriesModel.getCategoriesByName(qids.toList()))
+    }
+
+    /**
+     * Takes depict IDs as a parameter, converts into a slash separated String and Gets DepictItem
+     * from the server
+     *
+     * @param depictionsQIDs IDs of Depiction
+     * @return Flowable<List<DepictedItem>>
+     */
+    fun getDepictions(depictionsQIDs: List<String>): Flowable<List<DepictedItem>> {
+        val ids = joinQIDs(depictionsQIDs) ?: ""
+        return depictModel.getDepictions(ids).toFlowable()
+    }
+
+    /**
+     * Builds a string by joining all IDs divided by "|"
+     *
+     * @param depictionsQIDs IDs of depiction ex. ["Q11023","Q1356"]
+     * @return string ex. "Q11023|Q1356"
+     */
+    private fun joinQIDs(depictionsQIDs: List<String>?): String? {
+        return depictionsQIDs?.takeIf {
+            it.isNotEmpty()
+        }?.joinToString("|")
+    }
+
+    /**
+     * Returns nearest place matching the passed latitude and longitude
+     *
+     * @param decLatitude
+     * @param decLongitude
+     * @return
+     */
+    fun checkNearbyPlaces(decLatitude: Double, decLongitude: Double): Place? {
+        return try {
+            val fromWikidataQuery = nearbyPlaces.getFromWikidataQuery(
+                LatLng(decLatitude, decLongitude, 0.0f),
+                Locale.getDefault().language,
+                NEARBY_RADIUS_IN_KILO_METERS,
+                null
+            )
+            fromWikidataQuery?.firstOrNull()
+        } catch (e: Exception) {
+            Timber.e("Error fetching nearby places: %s", e.message)
+            null
+        }
+    }
+
+    fun useSimilarPictureCoordinates(imageCoordinates: ImageCoordinates, uploadItemIndex: Int) {
+        uploadModel.useSimilarPictureCoordinates(
+            imageCoordinates,
+            uploadItemIndex
+        )
+    }
+
+    fun isWMLSupportedForThisPlace(): Boolean {
+        return uploadModel.items.firstOrNull()?.isWLMUpload == true
+    }
+
+    /**
+     * Provides selected existing categories
+     *
+     * @return selected existing categories
+     */
+    fun getSelectedExistingCategories(): List<String> {
+        return categoriesModel.getSelectedExistingCategories()
+    }
+
+    /**
+     * Initialize existing categories
+     *
+     * @param selectedExistingCategories existing categories
+     */
+    fun setSelectedExistingCategories(selectedExistingCategories: List<String>) {
+        categoriesModel.setSelectedExistingCategories(
+            selectedExistingCategories.toMutableList()
+        )
+    }
+
+    /**
+     * Takes category names and Gets CategoryItem from the server
+     *
+     * @param categories names of Category
+     * @return Observable<List<CategoryItem>>
+     */
+    fun getCategories(categories: List<String>): Observable<List<CategoryItem>> {
+        return categoriesModel.getCategoriesByName(categories)
+            ?.map { it.toList() } ?: Observable.empty()
+    }
+}

app/src/main/java/fr/free/nrw/commons/review/ReviewActivity.java

@@ -1,334 +0,0 @@
-package fr.free.nrw.commons.review;
-
-import android.annotation.SuppressLint;
-import android.content.Context;
-import android.content.Intent;
-import android.graphics.PorterDuff;
-import android.graphics.drawable.Drawable;
-import android.os.Bundle;
-import android.view.Menu;
-import android.view.MenuInflater;
-import android.view.MenuItem;
-import android.view.MotionEvent;
-import android.view.View;
-import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentManager;
-import fr.free.nrw.commons.Media;
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.auth.AccountUtil;
-import fr.free.nrw.commons.databinding.ActivityReviewBinding;
-import fr.free.nrw.commons.delete.DeleteHelper;
-import fr.free.nrw.commons.media.MediaDetailFragment;
-import fr.free.nrw.commons.theme.BaseActivity;
-import fr.free.nrw.commons.utils.DialogUtil;
-import fr.free.nrw.commons.utils.ViewUtil;
-import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.disposables.CompositeDisposable;
-import io.reactivex.schedulers.Schedulers;
-import java.util.Locale;
-import javax.inject.Inject;
-
-public class ReviewActivity extends BaseActivity {
-
-
-    private ActivityReviewBinding binding;
-
-    MediaDetailFragment mediaDetailFragment;
-    public ReviewPagerAdapter reviewPagerAdapter;
-    public ReviewController reviewController;
-    @Inject
-    ReviewHelper reviewHelper;
-    @Inject
-    DeleteHelper deleteHelper;
-    /**
-     * Represent fragment for ReviewImage
-     * Use to call some methods of ReviewImage fragment
-     */
-     private ReviewImageFragment reviewImageFragment;
-
-    /**
-     * Flag to check whether there are any non-hidden categories in the File
-     */
-    private boolean hasNonHiddenCategories = false;
-
-    final String SAVED_MEDIA = "saved_media";
-    private Media media;
-
-    @Override
-    protected void onSaveInstanceState(Bundle outState) {
-        super.onSaveInstanceState(outState);
-        if (media != null) {
-            outState.putParcelable(SAVED_MEDIA, media);
-        }
-    }
-
-    /**
-     * Consumers should be simply using this method to use this activity.
-     *
-     * @param context
-     * @param title   Page title
-     */
-    public static void startYourself(Context context, String title) {
-        Intent reviewActivity = new Intent(context, ReviewActivity.class);
-        reviewActivity.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
-        reviewActivity.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
-        context.startActivity(reviewActivity);
-    }
-
-    private CompositeDisposable compositeDisposable = new CompositeDisposable();
-
-    public Media getMedia() {
-        return media;
-    }
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        binding = ActivityReviewBinding.inflate(getLayoutInflater());
-        setContentView(binding.getRoot());
-
-        setSupportActionBar(binding.toolbarBinding.toolbar);
-        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-        
-        reviewController = new ReviewController(deleteHelper, this);
-
-        reviewPagerAdapter = new ReviewPagerAdapter(getSupportFragmentManager());
-        binding.viewPagerReview.setAdapter(reviewPagerAdapter);
-        binding.pagerIndicatorReview.setViewPager(binding.viewPagerReview);
-        binding.pbReviewImage.setVisibility(View.VISIBLE);
-
-        Drawable d[]=binding.skipImage.getCompoundDrawablesRelative();
-        d[2].setColorFilter(getApplicationContext().getResources().getColor(R.color.button_blue), PorterDuff.Mode.SRC_IN);
-
-        if (savedInstanceState != null && savedInstanceState.getParcelable(SAVED_MEDIA) != null) {
-            updateImage(savedInstanceState.getParcelable(SAVED_MEDIA)); // Use existing media if we have one
-            setUpMediaDetailOnOrientation();
-        } else {
-            runRandomizer(); //Run randomizer whenever everything is ready so that a first random image will be added
-        }
-
-        binding.skipImage.setOnClickListener(view -> {
-            reviewImageFragment = getInstanceOfReviewImageFragment();
-            reviewImageFragment.disableButtons();
-            runRandomizer();
-        });
-
-        binding.reviewImageView.setOnClickListener(view ->setUpMediaDetailFragment());
-
-        binding.skipImage.setOnTouchListener((view, event) -> {
-            if (event.getAction() == MotionEvent.ACTION_UP && event.getRawX() >= (
-                    binding.skipImage.getRight() - binding.skipImage
-                            .getCompoundDrawables()[2].getBounds().width())) {
-                showSkipImageInfo();
-                return true;
-            }
-            return false;
-        });
-    }
-
-    @Override
-    public boolean onSupportNavigateUp() {
-        onBackPressed();
-        return true;
-    }
-
-    @SuppressLint("CheckResult")
-    public boolean runRandomizer() {
-        hasNonHiddenCategories = false;
-        binding.pbReviewImage.setVisibility(View.VISIBLE);
-        binding.viewPagerReview.setCurrentItem(0);
-        // Finds non-hidden categories from Media instance
-        compositeDisposable.add(reviewHelper.getRandomMedia()
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(this::checkWhetherFileIsUsedInWikis));
-        return true;
-    }
-
-    /**
-     * Check whether media is used or not in any Wiki Page
-     */
-    @SuppressLint("CheckResult")
-    private void checkWhetherFileIsUsedInWikis(final Media media) {
-        compositeDisposable.add(reviewHelper.checkFileUsage(media.getFilename())
-            .subscribeOn(Schedulers.io())
-            .observeOn(AndroidSchedulers.mainThread())
-            .subscribe(result -> {
-                // result false indicates media is not used in any wiki
-                if (!result) {
-                    // Finds non-hidden categories from Media instance
-                    findNonHiddenCategories(media);
-                } else {
-                    runRandomizer();
-                }
-            }));
-    }
-
-    /**
-     * Finds non-hidden categories and updates current image
-     */
-    private void findNonHiddenCategories(Media media) {
-        for(String key : media.getCategoriesHiddenStatus().keySet()) {
-            Boolean value = media.getCategoriesHiddenStatus().get(key);
-            // If non-hidden category is found then set hasNonHiddenCategories to true
-            // so that category review cannot be skipped
-            if(!value) {
-                hasNonHiddenCategories = true;
-                break;
-            }
-        }
-        reviewImageFragment = getInstanceOfReviewImageFragment();
-        reviewImageFragment.disableButtons();
-        updateImage(media);
-    }
-
-    @SuppressLint("CheckResult")
-    private void updateImage(Media media) {
-        reviewHelper.addViewedImagesToDB(media.getPageId());
-        this.media = media;
-        String fileName = media.getFilename();
-        if (fileName.length() == 0) {
-            ViewUtil.showShortSnackbar(binding.drawerLayout, R.string.error_review);
-            return;
-        }
-
-        //If The Media User and Current Session Username is same then Skip the Image
-        if (media.getUser() != null && media.getUser().equals(AccountUtil.getUserName(getApplicationContext()))) {
-            runRandomizer();
-            return;
-        }
-
-        binding.reviewImageView.setImageURI(media.getImageUrl());
-
-        reviewController.onImageRefreshed(media); //file name is updated
-        compositeDisposable.add(reviewHelper.getFirstRevisionOfFile(fileName)
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
-                .subscribe(revision -> {
-                    reviewController.firstRevision = revision;
-                    reviewPagerAdapter.updateFileInformation();
-                    @SuppressLint({"StringFormatInvalid", "LocalSuppress"}) String caption = String.format(getString(R.string.review_is_uploaded_by), fileName, revision.getUser());
-                    binding.tvImageCaption.setText(caption);
-                    binding.pbReviewImage.setVisibility(View.GONE);
-                    reviewImageFragment = getInstanceOfReviewImageFragment();
-                    reviewImageFragment.enableButtons();
-                }));
-        binding.viewPagerReview.setCurrentItem(0);
-    }
-
-    public void swipeToNext() {
-        int nextPos = binding.viewPagerReview.getCurrentItem() + 1;
-        // If currently at category fragment, then check whether the media has any non-hidden category
-        if (nextPos <= 3) {
-            binding.viewPagerReview.setCurrentItem(nextPos);
-            if (nextPos == 2) {
-                // The media has no non-hidden category. Such media are already flagged by server-side bots, so no need to review manually.
-                if (!hasNonHiddenCategories) {
-                    swipeToNext();
-                    return;
-                }
-            }
-        } else {
-            runRandomizer();
-        }
-    }
-
-    @Override
-    public void onDestroy() {
-        super.onDestroy();
-        compositeDisposable.clear();
-        binding = null;
-    }
-
-    public void showSkipImageInfo(){
-        DialogUtil.showAlertDialog(ReviewActivity.this,
-                getString(R.string.skip_image).toUpperCase(Locale.ROOT),
-                getString(R.string.skip_image_explanation),
-                getString(android.R.string.ok),
-                "",
-                null,
-                null);
-    }
-
-    public void showReviewImageInfo() {
-        DialogUtil.showAlertDialog(ReviewActivity.this,
-                getString(R.string.title_activity_review),
-                getString(R.string.review_image_explanation),
-                getString(android.R.string.ok),
-                "",
-                null,
-                null);
-    }
-
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        MenuInflater inflater = getMenuInflater();
-        inflater.inflate(R.menu.menu_review_activty, menu);
-        return super.onCreateOptionsMenu(menu);
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.menu_image_info:
-                showReviewImageInfo();
-                return true;
-        }
-        return super.onOptionsItemSelected(item);
-    }
-
-    /**
-     * this function return the instance of  reviewImageFragment
-     */
-    public ReviewImageFragment getInstanceOfReviewImageFragment(){
-        int currentItemOfReviewPager = binding.viewPagerReview.getCurrentItem();
-        reviewImageFragment = (ReviewImageFragment) reviewPagerAdapter.instantiateItem(binding.viewPagerReview, currentItemOfReviewPager);
-        return reviewImageFragment;
-    }
-
-    /**
-     * set up the media detail fragment when click on the review image
-     */
-    private void setUpMediaDetailFragment() {
-        if (binding.mediaDetailContainer.getVisibility() == View.GONE && media != null) {
-            binding.mediaDetailContainer.setVisibility(View.VISIBLE);
-            binding.reviewActivityContainer.setVisibility(View.INVISIBLE);
-            FragmentManager fragmentManager = getSupportFragmentManager();
-            mediaDetailFragment = new MediaDetailFragment();
-            Bundle bundle = new Bundle();
-            bundle.putParcelable("media", media);
-            mediaDetailFragment.setArguments(bundle);
-            fragmentManager.beginTransaction().add(R.id.mediaDetailContainer, mediaDetailFragment).
-                addToBackStack("MediaDetail").commit();
-        }
-    }
-
-    /**
-     * handle the back pressed event of this activity
-     * this function call every time when back button is pressed
-     */
-    @Override
-    public void onBackPressed() {
-        if (binding.mediaDetailContainer.getVisibility() == View.VISIBLE) {
-            binding.mediaDetailContainer.setVisibility(View.GONE);
-            binding.reviewActivityContainer.setVisibility(View.VISIBLE);
-        }
-        super.onBackPressed();
-    }
-
-    /**
-     * set up media detail fragment after orientation change
-     */
-    private void setUpMediaDetailOnOrientation() {
-        Fragment mediaDetailFragment = getSupportFragmentManager()
-            .findFragmentById(R.id.mediaDetailContainer);
-        if (mediaDetailFragment != null) {
-            binding.mediaDetailContainer.setVisibility(View.VISIBLE);
-            binding.reviewActivityContainer.setVisibility(View.INVISIBLE);
-            getSupportFragmentManager().beginTransaction()
-                .replace(R.id.mediaDetailContainer, mediaDetailFragment).commit();
-        }
-    }
-
-}

app/src/main/java/fr/free/nrw/commons/review/ReviewActivity.kt

@@ -0,0 +1,336 @@
+package fr.free.nrw.commons.review
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.Intent
+import android.graphics.PorterDuff
+import android.os.Bundle
+import android.view.Menu
+import android.view.MenuItem
+import android.view.MotionEvent
+import android.view.View
+import fr.free.nrw.commons.Media
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.auth.AccountUtil
+import fr.free.nrw.commons.databinding.ActivityReviewBinding
+import fr.free.nrw.commons.delete.DeleteHelper
+import fr.free.nrw.commons.media.MediaDetailFragment
+import fr.free.nrw.commons.theme.BaseActivity
+import fr.free.nrw.commons.utils.DialogUtil
+import fr.free.nrw.commons.utils.ViewUtil
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.schedulers.Schedulers
+import java.util.Locale
+import javax.inject.Inject
+
+class ReviewActivity : BaseActivity() {
+
+    private lateinit var binding: ActivityReviewBinding
+
+    private var mediaDetailFragment: MediaDetailFragment? = null
+    lateinit var reviewPagerAdapter: ReviewPagerAdapter
+    lateinit var reviewController: ReviewController
+
+    @Inject
+    lateinit var reviewHelper: ReviewHelper
+
+    @Inject
+    lateinit var deleteHelper: DeleteHelper
+
+    /**
+     * Represent fragment for ReviewImage
+     * Use to call some methods of ReviewImage fragment
+     */
+    private var reviewImageFragment: ReviewImageFragment? = null
+    private var hasNonHiddenCategories = false
+    var media: Media? = null
+
+    private val SAVED_MEDIA = "saved_media"
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        media?.let {
+            outState.putParcelable(SAVED_MEDIA, it)
+        }
+    }
+
+    /**
+     * Consumers should be simply using this method to use this activity.
+     *
+     * @param context
+     * @param title Page title
+     */
+    companion object {
+        fun startYourself(context: Context, title: String) {
+            val reviewActivity = Intent(context, ReviewActivity::class.java)
+            reviewActivity.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT)
+            reviewActivity.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
+            context.startActivity(reviewActivity)
+        }
+    }
+
+    @SuppressLint("ClickableViewAccessibility")
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = ActivityReviewBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+
+        setSupportActionBar(binding.toolbarBinding?.toolbar)
+        supportActionBar?.setDisplayHomeAsUpEnabled(true)
+
+        reviewController = ReviewController(deleteHelper, this)
+
+        reviewPagerAdapter = ReviewPagerAdapter(supportFragmentManager)
+        binding.viewPagerReview.adapter = reviewPagerAdapter
+        binding.pagerIndicatorReview.setViewPager(binding.viewPagerReview)
+        binding.pbReviewImage.visibility = View.VISIBLE
+
+        binding.skipImage.compoundDrawablesRelative[2]?.setColorFilter(
+            resources.getColor(R.color.button_blue),
+            PorterDuff.Mode.SRC_IN
+        )
+
+        if (savedInstanceState?.getParcelable<Media>(SAVED_MEDIA) != null) {
+            updateImage(savedInstanceState.getParcelable(SAVED_MEDIA)!!)
+            setUpMediaDetailOnOrientation()
+        } else {
+            runRandomizer()
+        }
+
+        binding.skipImage.setOnClickListener {
+            reviewImageFragment = getInstanceOfReviewImageFragment()
+            reviewImageFragment?.disableButtons()
+            runRandomizer()
+        }
+
+        binding.reviewImageView.setOnClickListener {
+            setUpMediaDetailFragment()
+        }
+
+        binding.skipImage.setOnTouchListener { _, event ->
+            if (event.action == MotionEvent.ACTION_UP &&
+                event.rawX >= (binding.skipImage.right - binding.skipImage.compoundDrawables[2].bounds.width())
+            ) {
+                showSkipImageInfo()
+                true
+            } else {
+                false
+            }
+        }
+    }
+
+    override fun onSupportNavigateUp(): Boolean {
+        onBackPressed()
+        return true
+    }
+
+    @SuppressLint("CheckResult")
+    fun runRandomizer(): Boolean {
+        hasNonHiddenCategories = false
+        binding.pbReviewImage.visibility = View.VISIBLE
+        binding.viewPagerReview.currentItem = 0
+
+        compositeDisposable.add(
+            reviewHelper.getRandomMedia()
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(::checkWhetherFileIsUsedInWikis)
+        )
+        return true
+    }
+
+    /**
+     * Check whether media is used or not in any Wiki Page
+     */
+    @SuppressLint("CheckResult")
+    private fun checkWhetherFileIsUsedInWikis(media: Media) {
+        compositeDisposable.add(
+            reviewHelper.checkFileUsage(media.filename)
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe { result ->
+                    if (!result) {
+                        findNonHiddenCategories(media)
+                    } else {
+                        runRandomizer()
+                    }
+                }
+        )
+    }
+
+    /**
+     * Finds non-hidden categories and updates current image
+     */
+    private fun findNonHiddenCategories(media: Media) {
+        this.media = media
+        // If non-hidden category is found then set hasNonHiddenCategories to true
+        // so that category review cannot be skipped
+        hasNonHiddenCategories = media.categoriesHiddenStatus.values.any { !it }
+        reviewImageFragment = getInstanceOfReviewImageFragment()
+        reviewImageFragment?.disableButtons()
+        updateImage(media)
+    }
+
+    @SuppressLint("CheckResult")
+    private fun updateImage(media: Media) {
+        reviewHelper.addViewedImagesToDB(media.pageId)
+        this.media = media
+        val fileName = media.filename
+
+        if (fileName.isNullOrEmpty()) {
+            ViewUtil.showShortSnackbar(binding.drawerLayout, R.string.error_review)
+            return
+        }
+
+        //If The Media User and Current Session Username is same then Skip the Image
+        if (media.user == AccountUtil.getUserName(applicationContext)) {
+            runRandomizer()
+            return
+        }
+
+        binding.reviewImageView.setImageURI(media.imageUrl)
+
+        reviewController.onImageRefreshed(media)    // filename is updated
+        compositeDisposable.add(
+            reviewHelper.getFirstRevisionOfFile(fileName)
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe { revision ->
+                    reviewController.firstRevision = revision
+                    reviewPagerAdapter.updateFileInformation()
+                    val caption = getString(
+                        R.string.review_is_uploaded_by,
+                        fileName,
+                        revision.user
+                    )
+                    binding.tvImageCaption.text = caption
+                    binding.pbReviewImage.visibility = View.GONE
+                    reviewImageFragment = getInstanceOfReviewImageFragment()
+                    reviewImageFragment?.enableButtons()
+                }
+        )
+        binding.viewPagerReview.currentItem = 0
+    }
+
+    fun swipeToNext() {
+        val nextPos = binding.viewPagerReview.currentItem + 1
+
+        // If currently at category fragment, then check whether the media has any non-hidden category
+        if (nextPos <= 3) {
+            binding.viewPagerReview.currentItem = nextPos
+            if (nextPos == 2 && !hasNonHiddenCategories)
+            {
+                // The media has no non-hidden category. Such media are already flagged by server-side bots, so no need to review manually.
+                swipeToNext()
+            }
+        } else {
+            runRandomizer()
+        }
+    }
+
+    public override fun onDestroy() {
+        super.onDestroy()
+        compositeDisposable.clear()
+    }
+
+    fun showSkipImageInfo() {
+        DialogUtil.showAlertDialog(
+            this,
+            getString(R.string.skip_image).uppercase(Locale.ROOT),
+            getString(R.string.skip_image_explanation),
+            getString(android.R.string.ok),
+            null,
+            null,
+            null
+        )
+    }
+
+    fun showReviewImageInfo() {
+        DialogUtil.showAlertDialog(
+            this,
+            getString(R.string.title_activity_review),
+            getString(R.string.review_image_explanation),
+            getString(android.R.string.ok),
+            null,
+            null,
+            null
+        )
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        menuInflater.inflate(R.menu.menu_review_activty, menu)
+        return super.onCreateOptionsMenu(menu)
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        return when (item.itemId) {
+            R.id.menu_image_info -> {
+                showReviewImageInfo()
+                true
+            }
+            else -> super.onOptionsItemSelected(item)
+        }
+    }
+
+    /**
+     * this function return the instance of  reviewImageFragment
+     */
+    private fun getInstanceOfReviewImageFragment(): ReviewImageFragment? {
+        val currentItemOfReviewPager = binding.viewPagerReview.currentItem
+        return reviewPagerAdapter.instantiateItem(
+            binding.viewPagerReview,
+            currentItemOfReviewPager
+        ) as? ReviewImageFragment
+    }
+
+    /**
+     * set up the media detail fragment when click on the review image
+     */
+    private fun setUpMediaDetailFragment() {
+        if (binding.mediaDetailContainer.visibility == View.GONE && media != null) {
+            binding.mediaDetailContainer.visibility = View.VISIBLE
+            binding.reviewActivityContainer.visibility = View.INVISIBLE
+            val fragmentManager = supportFragmentManager
+            mediaDetailFragment = MediaDetailFragment().apply {
+                arguments = Bundle().apply {
+                    putParcelable("media", media)
+                }
+            }
+            fragmentManager.beginTransaction()
+                .add(R.id.mediaDetailContainer, mediaDetailFragment!!)
+                .addToBackStack("MediaDetail")
+                .commit()
+        }
+    }
+
+    /**
+     * handle the back pressed event of this activity
+     * this function call every time when back button is pressed
+     */
+    @Deprecated("This method has been deprecated in favor of using the" +
+            "{@link OnBackPressedDispatcher} via {@link #getOnBackPressedDispatcher()}." +
+            "The OnBackPressedDispatcher controls how back button events are dispatched" +
+            "to one or more {@link OnBackPressedCallback} objects.")
+    override fun onBackPressed() {
+        if (binding.mediaDetailContainer.visibility == View.VISIBLE) {
+            binding.mediaDetailContainer.visibility = View.GONE
+            binding.reviewActivityContainer.visibility = View.VISIBLE
+        }
+        super.onBackPressed()
+    }
+
+    /**
+     * set up media detail fragment after orientation change
+     */
+    private fun setUpMediaDetailOnOrientation() {
+        val fragment = supportFragmentManager.findFragmentById(R.id.mediaDetailContainer)
+        fragment?.let {
+            binding.mediaDetailContainer.visibility = View.VISIBLE
+            binding.reviewActivityContainer.visibility = View.INVISIBLE
+            supportFragmentManager.beginTransaction()
+                .replace(R.id.mediaDetailContainer, it)
+                .commit()
+        }
+    }
+}
+

app/src/main/java/fr/free/nrw/commons/review/ReviewController.java

@@ -1,220 +0,0 @@
-package fr.free.nrw.commons.review;
-
-import android.annotation.SuppressLint;
-import android.app.Activity;
-import android.app.NotificationManager;
-import android.content.Context;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.core.app.NotificationCompat;
-
-import fr.free.nrw.commons.auth.SessionManager;
-import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException;
-import fr.free.nrw.commons.wikidata.mwapi.MwQueryPage;
-
-import java.util.ArrayList;
-import java.util.concurrent.Callable;
-
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-
-import fr.free.nrw.commons.CommonsApplication;
-import fr.free.nrw.commons.Media;
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.actions.PageEditClient;
-import fr.free.nrw.commons.actions.ThanksClient;
-import fr.free.nrw.commons.delete.DeleteHelper;
-import fr.free.nrw.commons.di.ApplicationlessInjection;
-import fr.free.nrw.commons.utils.ViewUtil;
-import io.reactivex.Observable;
-import io.reactivex.ObservableSource;
-import io.reactivex.android.schedulers.AndroidSchedulers;
-import io.reactivex.schedulers.Schedulers;
-import timber.log.Timber;
-
-@Singleton
-public class ReviewController {
-    private static final int NOTIFICATION_SEND_THANK = 0x102;
-    private static final int NOTIFICATION_CHECK_CATEGORY = 0x101;
-    protected static ArrayList<String> categories;
-    @Inject
-    ThanksClient thanksClient;
-
-    @Inject
-    SessionManager sessionManager;
-    private final DeleteHelper deleteHelper;
-    @Nullable
-    MwQueryPage.Revision firstRevision; // TODO: maybe we can expand this class to include fileName
-    @Inject
-    @Named("commons-page-edit")
-    PageEditClient pageEditClient;
-    private NotificationManager notificationManager;
-    private NotificationCompat.Builder notificationBuilder;
-    private Media media;
-
-    ReviewController(DeleteHelper deleteHelper, Context context) {
-        this.deleteHelper = deleteHelper;
-        CommonsApplication.createNotificationChannel(context.getApplicationContext());
-        notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
-        notificationBuilder = new NotificationCompat.Builder(context, CommonsApplication.NOTIFICATION_CHANNEL_ID_ALL);
-    }
-
-    void onImageRefreshed(Media media) {
-        this.media = media;
-    }
-
-    public Media getMedia() {
-        return media;
-    }
-
-    public enum DeleteReason {
-        SPAM,
-        COPYRIGHT_VIOLATION
-    }
-
-    void reportSpam(@NonNull Activity activity, ReviewCallback reviewCallback) {
-        Timber.d("Report spam for %s", media.getFilename());
-        deleteHelper.askReasonAndExecute(media,
-                activity,
-                activity.getResources().getString(R.string.review_spam_report_question),
-                DeleteReason.SPAM,
-                reviewCallback);
-    }
-
-    void reportPossibleCopyRightViolation(@NonNull Activity activity, ReviewCallback reviewCallback) {
-        Timber.d("Report spam for %s", media.getFilename());
-        deleteHelper.askReasonAndExecute(media,
-                activity,
-                activity.getResources().getString(R.string.review_c_violation_report_question),
-                DeleteReason.COPYRIGHT_VIOLATION,
-                reviewCallback);
-    }
-
-    @SuppressLint("CheckResult")
-    void reportWrongCategory(@NonNull Activity activity, ReviewCallback reviewCallback) {
-        Context context = activity.getApplicationContext();
-        ApplicationlessInjection
-                .getInstance(context)
-                .getCommonsApplicationComponent()
-                .inject(this);
-
-        ViewUtil.showShortToast(context, context.getString(R.string.check_category_toast, media.getDisplayTitle()));
-
-        publishProgress(context, 0);
-        String summary = context.getString(R.string.check_category_edit_summary);
-        Observable.defer((Callable<ObservableSource<Boolean>>) () ->
-                pageEditClient.appendEdit(media.getFilename(), "\n{{subst:chc}}\n", summary))
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
-                .subscribe((result) -> {
-                    publishProgress(context, 2);
-                    String message;
-                    String title;
-
-                    if (result) {
-                        title = context.getString(R.string.check_category_success_title);
-                        message = context.getString(R.string.check_category_success_message, media.getDisplayTitle());
-                        reviewCallback.onSuccess();
-                    } else {
-                        title = context.getString(R.string.check_category_failure_title);
-                        message = context.getString(R.string.check_category_failure_message, media.getDisplayTitle());
-                        reviewCallback.onFailure();
-                    }
-
-                    showNotification(title, message);
-
-                }, Timber::e);
-    }
-
-    private void publishProgress(@NonNull Context context, int i) {
-        int[] messages = new int[]{R.string.getting_edit_token, R.string.check_category_adding_template};
-        String message = "";
-        if (0 < i && i < messages.length) {
-            message = context.getString(messages[i]);
-        }
-
-        notificationBuilder.setContentTitle(context.getString(R.string.check_category_notification_title, media.getDisplayTitle()))
-                .setStyle(new NotificationCompat.BigTextStyle()
-                        .bigText(message))
-                .setSmallIcon(R.drawable.ic_launcher)
-                .setProgress(messages.length, i, false)
-                .setOngoing(true);
-        notificationManager.notify(NOTIFICATION_CHECK_CATEGORY, notificationBuilder.build());
-    }
-
-    @SuppressLint({"CheckResult", "StringFormatInvalid"})
-    void sendThanks(@NonNull Activity activity) {
-        Context context = activity.getApplicationContext();
-        ApplicationlessInjection
-                .getInstance(context)
-                .getCommonsApplicationComponent()
-                .inject(this);
-        ViewUtil.showShortToast(context, context.getString(R.string.send_thank_toast, media.getDisplayTitle()));
-
-        if (firstRevision == null) {
-            return;
-        }
-
-        Observable.defer((Callable<ObservableSource<Boolean>>) () -> thanksClient.thank(firstRevision.getRevisionId()))
-                .subscribeOn(Schedulers.io())
-                .observeOn(AndroidSchedulers.mainThread())
-            .subscribe(result -> {
-                displayThanksToast(context, result);
-            }, throwable -> {
-                if (throwable instanceof InvalidLoginTokenException) {
-                    final String username = sessionManager.getUserName();
-                    final CommonsApplication.BaseLogoutListener logoutListener = new CommonsApplication.BaseLogoutListener(
-                        activity,
-                       activity.getString(R.string.invalid_login_message),
-                        username
-                    );
-
-                    CommonsApplication.getInstance().clearApplicationData(
-                       activity, logoutListener);
-                } else {
-                    Timber.e(throwable);
-                }
-            });
-    }
-
-    @SuppressLint("StringFormatInvalid")
-    private void displayThanksToast(final Context context, final boolean result){
-        final String message;
-        final String title;
-        if (result) {
-            title = context.getString(R.string.send_thank_success_title);
-            message = context.getString(R.string.send_thank_success_message, media.getDisplayTitle());
-        } else {
-            title = context.getString(R.string.send_thank_failure_title);
-            message = context.getString(R.string.send_thank_failure_message, media.getDisplayTitle());
-        }
-
-        ViewUtil.showShortToast(context,message);
-    }
-
-    private void showNotification(String title, String message) {
-        notificationBuilder.setDefaults(NotificationCompat.DEFAULT_ALL)
-                .setContentTitle(title)
-                .setStyle(new NotificationCompat.BigTextStyle()
-                        .bigText(message))
-                .setSmallIcon(R.drawable.ic_launcher)
-                .setProgress(0, 0, false)
-                .setOngoing(false)
-                .setPriority(NotificationCompat.PRIORITY_HIGH);
-        notificationManager.notify(NOTIFICATION_SEND_THANK, notificationBuilder.build());
-    }
-
-    public interface ReviewCallback {
-        void onSuccess();
-
-        void onFailure();
-
-        void onTokenException(Exception e);
-
-        void disableButtons();
-
-        void enableButtons();
-    }
-}

app/src/main/java/fr/free/nrw/commons/review/ReviewController.kt

@@ -0,0 +1,231 @@
+package fr.free.nrw.commons.review
+
+import android.annotation.SuppressLint
+import android.app.Activity
+import android.app.NotificationManager
+import android.content.Context
+
+import androidx.core.app.NotificationCompat
+
+import fr.free.nrw.commons.auth.SessionManager
+import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException
+import fr.free.nrw.commons.wikidata.mwapi.MwQueryPage
+
+import java.util.ArrayList
+import java.util.concurrent.Callable
+
+import javax.inject.Inject
+import javax.inject.Named
+import javax.inject.Singleton
+
+import fr.free.nrw.commons.CommonsApplication
+import fr.free.nrw.commons.Media
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.actions.PageEditClient
+import fr.free.nrw.commons.actions.ThanksClient
+import fr.free.nrw.commons.delete.DeleteHelper
+import fr.free.nrw.commons.di.ApplicationlessInjection
+import fr.free.nrw.commons.utils.ViewUtil
+import io.reactivex.Observable
+import io.reactivex.ObservableSource
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.schedulers.Schedulers
+import timber.log.Timber
+
+
+@Singleton
+class ReviewController @Inject constructor(
+    private val deleteHelper: DeleteHelper,
+    context: Context
+) {
+
+    companion object {
+        private const val NOTIFICATION_SEND_THANK = 0x102
+        private const val NOTIFICATION_CHECK_CATEGORY = 0x101
+        protected var categories: ArrayList<String> = ArrayList()
+    }
+
+    @Inject
+    lateinit var thanksClient: ThanksClient
+
+    @Inject
+    lateinit var sessionManager: SessionManager
+
+    @Inject
+    @field: Named("commons-page-edit")
+    lateinit var pageEditClient: PageEditClient
+
+    var firstRevision: MwQueryPage.Revision? = null // TODO: maybe we can expand this class to include fileName
+
+    private val notificationManager: NotificationManager =
+        context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+    private val notificationBuilder: NotificationCompat.Builder =
+        NotificationCompat.Builder(context, CommonsApplication.NOTIFICATION_CHANNEL_ID_ALL)
+
+    var media: Media? = null
+
+    init {
+        CommonsApplication.createNotificationChannel(context.applicationContext)
+    }
+
+    fun onImageRefreshed(media: Media) {
+        this.media = media
+    }
+
+    enum class DeleteReason {
+        SPAM,
+        COPYRIGHT_VIOLATION
+    }
+
+    fun reportSpam(activity: Activity, reviewCallback: ReviewCallback) {
+        Timber.d("Report spam for %s", media?.filename)
+        deleteHelper.askReasonAndExecute(
+            media,
+            activity,
+            activity.resources.getString(R.string.review_spam_report_question),
+            DeleteReason.SPAM,
+            reviewCallback
+        )
+    }
+
+    fun reportPossibleCopyRightViolation(activity: Activity, reviewCallback: ReviewCallback) {
+        Timber.d("Report copyright violation for %s", media?.filename)
+        deleteHelper.askReasonAndExecute(
+            media,
+            activity,
+            activity.resources.getString(R.string.review_c_violation_report_question),
+            DeleteReason.COPYRIGHT_VIOLATION,
+            reviewCallback
+        )
+    }
+
+    @SuppressLint("CheckResult")
+    fun reportWrongCategory(activity: Activity, reviewCallback: ReviewCallback) {
+        val context = activity.applicationContext
+        ApplicationlessInjection
+            .getInstance(context)
+            .commonsApplicationComponent
+            .inject(this)
+
+        ViewUtil.showShortToast(
+            context,
+            context.getString(R.string.check_category_toast, media?.displayTitle)
+        )
+
+        publishProgress(context, 0)
+        val summary = context.getString(R.string.check_category_edit_summary)
+
+        Observable.defer {
+            pageEditClient.appendEdit(media?.filename ?: "", "\n{{subst:chc}}\n", summary)
+        }
+            .subscribeOn(Schedulers.io())
+            .observeOn(AndroidSchedulers.mainThread())
+            .subscribe({ result ->
+                publishProgress(context, 2)
+                val (title, message) = if (result) {
+                    reviewCallback.onSuccess()
+                    context.getString(R.string.check_category_success_title) to
+                            context.getString(R.string.check_category_success_message, media?.displayTitle)
+                } else {
+                    reviewCallback.onFailure()
+                    context.getString(R.string.check_category_failure_title) to
+                            context.getString(R.string.check_category_failure_message, media?.displayTitle)
+                }
+                showNotification(title, message)
+            }, Timber::e)
+    }
+
+    private fun publishProgress(context: Context, progress: Int) {
+        val messages = arrayOf(
+            R.string.getting_edit_token,
+            R.string.check_category_adding_template
+        )
+
+        val message = if (progress in 1 until messages.size) {
+            context.getString(messages[progress])
+        } else ""
+
+        notificationBuilder.setContentTitle(
+            context.getString(
+                R.string.check_category_notification_title,
+                media?.displayTitle
+            )
+        )
+            .setStyle(NotificationCompat.BigTextStyle().bigText(message))
+            .setSmallIcon(R.drawable.ic_launcher)
+            .setProgress(messages.size, progress, false)
+            .setOngoing(true)
+
+        notificationManager.notify(NOTIFICATION_CHECK_CATEGORY, notificationBuilder.build())
+    }
+
+    @SuppressLint("CheckResult")
+    fun sendThanks(activity: Activity) {
+        val context = activity.applicationContext
+        ApplicationlessInjection
+            .getInstance(context)
+            .commonsApplicationComponent
+            .inject(this)
+
+        ViewUtil.showShortToast(
+            context,
+            context.getString(R.string.send_thank_toast, media?.displayTitle)
+        )
+
+        if (firstRevision == null) return
+
+        Observable.defer {
+            thanksClient.thank(firstRevision!!.revisionId)
+        }
+            .subscribeOn(Schedulers.io())
+            .observeOn(AndroidSchedulers.mainThread())
+            .subscribe({ result ->
+                displayThanksToast(context, result)
+            }, { throwable ->
+                if (throwable is InvalidLoginTokenException) {
+                    val username = sessionManager.userName
+                    val logoutListener = CommonsApplication.BaseLogoutListener(
+                        activity,
+                        activity.getString(R.string.invalid_login_message),
+                        username
+                    )
+                    CommonsApplication.instance.clearApplicationData(activity, logoutListener)
+                } else {
+                    Timber.e(throwable)
+                }
+            })
+    }
+
+    @SuppressLint("StringFormatInvalid")
+    private fun displayThanksToast(context: Context, result: Boolean) {
+        val (title, message) = if (result) {
+            context.getString(R.string.send_thank_success_title) to
+                    context.getString(R.string.send_thank_success_message, media?.displayTitle)
+        } else {
+            context.getString(R.string.send_thank_failure_title) to
+                    context.getString(R.string.send_thank_failure_message, media?.displayTitle)
+        }
+
+        ViewUtil.showShortToast(context, message)
+    }
+
+    private fun showNotification(title: String, message: String) {
+        notificationBuilder.setDefaults(NotificationCompat.DEFAULT_ALL)
+            .setContentTitle(title)
+            .setStyle(NotificationCompat.BigTextStyle().bigText(message))
+            .setSmallIcon(R.drawable.ic_launcher)
+            .setProgress(0, 0, false)
+            .setOngoing(false)
+            .setPriority(NotificationCompat.PRIORITY_HIGH)
+
+        notificationManager.notify(NOTIFICATION_SEND_THANK, notificationBuilder.build())
+    }
+
+    interface ReviewCallback {
+        fun onSuccess()
+        fun onFailure()
+        fun onTokenException(e: Exception)
+        fun disableButtons()
+        fun enableButtons()
+    }
+}

app/src/main/java/fr/free/nrw/commons/review/ReviewDao.kt

@@ -1,15 +1,15 @@
-package fr.free.nrw.commons.review;
+package fr.free.nrw.commons.review
 
-import androidx.room.Dao;
+import androidx.room.Dao
-import androidx.room.Insert;
+import androidx.room.Insert
-import androidx.room.OnConflictStrategy;
+import androidx.room.OnConflictStrategy
-import androidx.room.Query;
+import androidx.room.Query
 
 /**
  * Dao interface for reviewed images database
  */
 @Dao
-public interface ReviewDao {
+interface ReviewDao {
 
     /**
      * Inserts reviewed/skipped image identifier into the database
@@ -17,7 +17,7 @@ public interface ReviewDao {
      * @param reviewEntity
      */
     @Insert(onConflict = OnConflictStrategy.IGNORE)
-    void insert(ReviewEntity reviewEntity);
+    fun insert(reviewEntity: ReviewEntity)
 
     /**
      * Checks if the image has already been reviewed/skipped by the user
@@ -26,7 +26,6 @@ public interface ReviewDao {
      * @param imageId
      * @return
      */
-    @Query( "SELECT EXISTS (SELECT * from `reviewed-images` where imageId = (:imageId))")
+    @Query("SELECT EXISTS (SELECT * from `reviewed-images` where imageId = (:imageId))")
-    Boolean isReviewedAlready(String imageId);
+    fun isReviewedAlready(imageId: String): Boolean
-
+}
-}

app/src/main/java/fr/free/nrw/commons/review/ReviewEntity.java

@@ -1,19 +0,0 @@
-package fr.free.nrw.commons.review;
-
-import androidx.annotation.NonNull;
-import androidx.room.Entity;
-import androidx.room.PrimaryKey;
-
-/**
- * Entity to store reviewed/skipped images identifier
- */
-@Entity(tableName = "reviewed-images")
-public class ReviewEntity {
-    @PrimaryKey
-    @NonNull
-    String imageId;
-
-    public ReviewEntity(String imageId) {
-        this.imageId = imageId;
-    }
-}

app/src/main/java/fr/free/nrw/commons/review/ReviewEntity.kt

@@ -0,0 +1,13 @@
+package fr.free.nrw.commons.review
+
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+/**
+ * Entity to store reviewed/skipped images identifier
+ */
+@Entity(tableName = "reviewed-images")
+data class ReviewEntity(
+    @PrimaryKey
+    val imageId: String
+)

app/src/main/java/fr/free/nrw/commons/review/ReviewHelper.kt

@@ -77,7 +77,7 @@ class ReviewHelper
          * @param image
          * @return
          */
-        fun getReviewStatus(image: String?): Boolean = dao?.isReviewedAlready(image) ?: false
+        fun getReviewStatus(image: String?): Boolean = image?.let { dao?.isReviewedAlready(it) } ?: false
 
         /**
          * Gets the first revision of the file from filename
@@ -132,7 +132,7 @@ class ReviewHelper
          */
         fun addViewedImagesToDB(imageId: String?) {
             Completable
-                .fromAction { dao!!.insert(ReviewEntity(imageId)) }
+                .fromAction { imageId?.let { ReviewEntity(it) }?.let { dao!!.insert(it) } }
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(

app/src/main/java/fr/free/nrw/commons/review/ReviewImageFragment.java

@@ -1,262 +0,0 @@
-package fr.free.nrw.commons.review;
-
-import android.graphics.Color;
-import android.os.Bundle;
-import android.text.Html;
-import android.text.TextUtils;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import androidx.annotation.NonNull;
-import fr.free.nrw.commons.CommonsApplication;
-import fr.free.nrw.commons.Media;
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.auth.SessionManager;
-import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException;
-import fr.free.nrw.commons.databinding.FragmentReviewImageBinding;
-import fr.free.nrw.commons.di.CommonsDaggerSupportFragment;
-import java.util.ArrayList;
-import java.util.List;
-import javax.inject.Inject;
-
-public class ReviewImageFragment extends CommonsDaggerSupportFragment {
-
-    static final int CATEGORY = 2;
-    private static final int SPAM = 0;
-    private static final int COPYRIGHT = 1;
-    private static final int THANKS = 3;
-
-    private int position;
-
-    private FragmentReviewImageBinding binding;
-
-    @Inject
-    SessionManager sessionManager;
-
-
-    // Constant variable used to store user's key name for onSaveInstanceState method
-    private final String SAVED_USER = "saved_user";
-
-    // Variable that stores the value of user
-    private String user;
-
-    public void update(final int position) {
-        this.position = position;
-    }
-
-    private String updateCategoriesQuestion() {
-        final Media media = getReviewActivity().getMedia();
-        if (media != null && media.getCategoriesHiddenStatus() != null && isAdded()) {
-            // Filter category name attribute from all categories
-            final List<String> categories = new ArrayList<>();
-            for(final String key : media.getCategoriesHiddenStatus().keySet()) {
-                String value = String.valueOf(key);
-                // Each category returned has a format like "Category:<some-category-name>"
-                // so remove the prefix "Category:"
-                final int index = key.indexOf("Category:");
-                if(index == 0) {
-                    value = key.substring(9);
-                }
-                categories.add(value);
-            }
-            String catString = TextUtils.join(", ", categories);
-            if (catString != null && !catString.equals("") && binding.tvReviewQuestionContext != null) {
-                catString = "<b>" + catString + "</b>";
-                final String stringToConvertHtml = String.format(getResources().getString(R.string.review_category_explanation), catString);
-                return Html.fromHtml(stringToConvertHtml).toString();
-            }
-        }
-        return getResources().getString(R.string.review_no_category);
-    }
-
-    @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-    }
-
-    @Override
-    public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
-                             final Bundle savedInstanceState) {
-        position = getArguments().getInt("position");
-        binding = FragmentReviewImageBinding.inflate(inflater, container, false);
-
-        final String question;
-        String explanation=null;
-        String yesButtonText;
-        final String noButtonText;
-
-        binding.buttonYes.setOnClickListener(view -> onYesButtonClicked());
-
-        switch (position) {
-            case SPAM:
-                question = getString(R.string.review_spam);
-                explanation = getString(R.string.review_spam_explanation);
-                yesButtonText = getString(R.string.yes);
-                noButtonText = getString(R.string.no);
-                binding.buttonNo.setOnClickListener(view -> getReviewActivity()
-                        .reviewController.reportSpam(requireActivity(), getReviewCallback()));
-                break;
-            case COPYRIGHT:
-                enableButtons();
-                question = getString(R.string.review_copyright);
-                explanation = getString(R.string.review_copyright_explanation);
-                yesButtonText = getString(R.string.yes);
-                noButtonText = getString(R.string.no);
-                binding.buttonNo.setOnClickListener(view -> getReviewActivity()
-                        .reviewController
-                        .reportPossibleCopyRightViolation(requireActivity(), getReviewCallback()));
-                break;
-            case CATEGORY:
-                enableButtons();
-                question = getString(R.string.review_category);
-                explanation = updateCategoriesQuestion();
-                yesButtonText = getString(R.string.yes);
-                noButtonText = getString(R.string.no);
-                binding.buttonNo.setOnClickListener(view -> {
-                    getReviewActivity()
-                            .reviewController
-                            .reportWrongCategory(requireActivity(), getReviewCallback());
-                    getReviewActivity().swipeToNext();
-                });
-                break;
-            case THANKS:
-                enableButtons();
-                question = getString(R.string.review_thanks);
-
-                if (getReviewActivity().reviewController.firstRevision != null) {
-                    user = getReviewActivity().reviewController.firstRevision.getUser();
-                } else {
-                    if(savedInstanceState != null) {
-                        user = savedInstanceState.getString(SAVED_USER);
-                    }
-                }
-
-                //if the user is null because of whatsoever reason, review will not be sent anyways
-                if (!TextUtils.isEmpty(user)) {
-                    explanation = getString(R.string.review_thanks_explanation, user);
-                }
-
-                // Note that the yes and no buttons are swapped in this section
-                yesButtonText = getString(R.string.review_thanks_yes_button_text);
-                noButtonText = getString(R.string.review_thanks_no_button_text);
-                binding.buttonYes.setTextColor(Color.parseColor("#116aaa"));
-                binding.buttonNo.setTextColor(Color.parseColor("#228b22"));
-                binding.buttonNo.setOnClickListener(view -> {
-                    getReviewActivity().reviewController.sendThanks(getReviewActivity());
-                    getReviewActivity().swipeToNext();
-                });
-                break;
-            default:
-                enableButtons();
-                question = "How did we get here?";
-                explanation = "No idea.";
-                yesButtonText = "yes";
-                noButtonText = "no";
-        }
-
-        binding.tvReviewQuestion.setText(question);
-        binding.tvReviewQuestionContext.setText(explanation);
-        binding.buttonYes.setText(yesButtonText);
-        binding.buttonNo.setText(noButtonText);
-        return binding.getRoot();
-    }
-
-
-    /**
-     * This method will be called when configuration changes happen
-     *
-     * @param outState
-     */
-    @Override
-    public void onSaveInstanceState(@NonNull Bundle outState) {
-        super.onSaveInstanceState(outState);
-
-        //Save user name when configuration changes happen
-        outState.putString(SAVED_USER, user);
-    }
-
-    private ReviewController.ReviewCallback getReviewCallback() {
-        return new ReviewController
-                .ReviewCallback() {
-            @Override
-            public void onSuccess() {
-                getReviewActivity().runRandomizer();
-            }
-
-            @Override
-            public void onFailure() {
-                //do nothing
-            }
-
-            @Override
-            public void onTokenException(final Exception e) {
-                if (e instanceof InvalidLoginTokenException){
-                    final String username = sessionManager.getUserName();
-                    final CommonsApplication.BaseLogoutListener logoutListener = new CommonsApplication.BaseLogoutListener(
-                        getActivity(),
-                        requireActivity().getString(R.string.invalid_login_message),
-                        username
-                    );
-
-                    CommonsApplication.getInstance().clearApplicationData(
-                        requireActivity(), logoutListener);
-
-                }
-            }
-
-            /**
-             * This function is called when an image is being loaded
-             * to disable the review buttons
-             */
-            @Override
-            public void disableButtons() {
-                ReviewImageFragment.this.disableButtons();
-            }
-
-            /**
-             * This function is called when an image has
-             * been loaded to enable the review buttons.
-             */
-            @Override
-            public void enableButtons() {
-                ReviewImageFragment.this.enableButtons();
-            }
-        };
-    }
-
-    /**
-     * This function is called when an image has
-     * been loaded to enable the review buttons.
-     */
-    public void enableButtons() {
-        binding.buttonYes.setEnabled(true);
-        binding.buttonYes.setAlpha(1);
-        binding.buttonNo.setEnabled(true);
-        binding.buttonNo.setAlpha(1);
-    }
-
-    /**
-     * This function is called when an image is being loaded
-     * to disable the review buttons
-     */
-    public void disableButtons() {
-        binding.buttonYes.setEnabled(false);
-        binding.buttonYes.setAlpha(0.5f);
-        binding.buttonNo.setEnabled(false);
-        binding.buttonNo.setAlpha(0.5f);
-    }
-
-    void onYesButtonClicked() {
-        getReviewActivity().swipeToNext();
-    }
-
-    private ReviewActivity getReviewActivity() {
-        return (ReviewActivity) requireActivity();
-    }
-
-    @Override
-    public void onDestroy() {
-        super.onDestroy();
-        binding = null;
-    }
-}

app/src/main/java/fr/free/nrw/commons/review/ReviewImageFragment.kt

@@ -0,0 +1,251 @@
+package fr.free.nrw.commons.review
+
+import android.graphics.Color
+import android.os.Bundle
+import android.text.Html
+import android.text.TextUtils
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import fr.free.nrw.commons.CommonsApplication
+import fr.free.nrw.commons.Media
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.auth.SessionManager
+import fr.free.nrw.commons.auth.csrf.InvalidLoginTokenException
+import fr.free.nrw.commons.databinding.FragmentReviewImageBinding
+import fr.free.nrw.commons.di.CommonsDaggerSupportFragment
+import java.util.ArrayList
+import javax.inject.Inject
+
+
+class ReviewImageFragment : CommonsDaggerSupportFragment() {
+
+    companion object {
+        const val CATEGORY = 2
+        private const val SPAM = 0
+        private const val COPYRIGHT = 1
+        private const val THANKS = 3
+    }
+
+    private var position: Int = 0
+    private var binding: FragmentReviewImageBinding? = null
+
+    @Inject
+    lateinit var sessionManager: SessionManager
+
+    // Constant variable used to store user's key name for onSaveInstanceState method
+    private val SAVED_USER = "saved_user"
+
+    // Variable that stores the value of user
+    private var user: String? = null
+
+    fun update(position: Int) {
+        this.position = position
+    }
+
+    private fun updateCategoriesQuestion(): String {
+        val media = reviewActivity.media
+        if (media?.categoriesHiddenStatus != null && isAdded) {
+            // Filter category name attribute from all categories
+            val categories = media.categoriesHiddenStatus.keys.map { key ->
+                var value = key
+                // Each category returned has a format like "Category:<some-category-name>"
+                // so remove the prefix "Category:"
+                if (key.startsWith("Category:")) {
+                    value = key.substring(9)
+                }
+                value
+            }
+
+            val catString = categories.joinToString(", ")
+            if (catString.isNotEmpty() && binding?.tvReviewQuestionContext != null) {
+                val formattedCatString = "<b>$catString</b>"
+                val stringToConvertHtml = getString(
+                    R.string.review_category_explanation,
+                    formattedCatString
+                )
+                return Html.fromHtml(stringToConvertHtml).toString()
+            }
+        }
+        return getString(R.string.review_no_category)
+    }
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
+        position = requireArguments().getInt("position")
+        binding = FragmentReviewImageBinding.inflate(inflater, container, false)
+
+        val question: String
+        var explanation: String? = null
+        val yesButtonText: String
+        val noButtonText: String
+
+        binding?.buttonYes?.setOnClickListener { onYesButtonClicked() }
+
+        when (position) {
+            SPAM -> {
+                question = getString(R.string.review_spam)
+                explanation = getString(R.string.review_spam_explanation)
+                yesButtonText = getString(R.string.yes)
+                noButtonText = getString(R.string.no)
+                binding?.buttonNo?.setOnClickListener {
+                    reviewActivity.reviewController.reportSpam(requireActivity(), reviewCallback)
+                }
+            }
+            COPYRIGHT -> {
+                enableButtons()
+                question = getString(R.string.review_copyright)
+                explanation = getString(R.string.review_copyright_explanation)
+                yesButtonText = getString(R.string.yes)
+                noButtonText = getString(R.string.no)
+                binding?.buttonNo?.setOnClickListener {
+                    reviewActivity.reviewController.reportPossibleCopyRightViolation(
+                        requireActivity(),
+                        reviewCallback
+                    )
+                }
+            }
+            CATEGORY -> {
+                enableButtons()
+                question = getString(R.string.review_category)
+                explanation = updateCategoriesQuestion()
+                yesButtonText = getString(R.string.yes)
+                noButtonText = getString(R.string.no)
+                binding?.buttonNo?.setOnClickListener {
+                    reviewActivity.reviewController.reportWrongCategory(
+                        requireActivity(),
+                        reviewCallback
+                    )
+                    reviewActivity.swipeToNext()
+                }
+            }
+            THANKS -> {
+                enableButtons()
+                question = getString(R.string.review_thanks)
+
+                user = reviewActivity.reviewController.firstRevision?.user
+                    ?: savedInstanceState?.getString(SAVED_USER)
+
+                //if the user is null because of whatsoever reason, review will not be sent anyways
+                if (!user.isNullOrEmpty()) {
+                    explanation = getString(R.string.review_thanks_explanation, user)
+                }
+
+                // Note that the yes and no buttons are swapped in this section
+                yesButtonText = getString(R.string.review_thanks_yes_button_text)
+                noButtonText = getString(R.string.review_thanks_no_button_text)
+                binding?.buttonYes?.setTextColor(Color.parseColor("#116aaa"))
+                binding?.buttonNo?.setTextColor(Color.parseColor("#228b22"))
+                binding?.buttonNo?.setOnClickListener {
+                    reviewActivity.reviewController.sendThanks(requireActivity())
+                    reviewActivity.swipeToNext()
+                }
+            }
+            else -> {
+                enableButtons()
+                question = "How did we get here?"
+                explanation = "No idea."
+                yesButtonText = "yes"
+                noButtonText = "no"
+            }
+        }
+
+        binding?.apply {
+            tvReviewQuestion.text = question
+            tvReviewQuestionContext.text = explanation
+            buttonYes.text = yesButtonText
+            buttonNo.text = noButtonText
+        }
+        return binding?.root
+    }
+
+    /**
+     * This method will be called when configuration changes happen
+     *
+     * @param outState
+     */
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        //Save user name when configuration changes happen
+        outState.putString(SAVED_USER, user)
+    }
+
+    private val reviewCallback: ReviewController.ReviewCallback
+        get() = object : ReviewController.ReviewCallback {
+            override fun onSuccess() {
+                reviewActivity.runRandomizer()
+            }
+
+            override fun onFailure() {
+                //do nothing
+            }
+
+            override fun onTokenException(e: Exception) {
+                if (e is InvalidLoginTokenException) {
+                    val username = sessionManager.userName
+                    val logoutListener = activity?.let {
+                        CommonsApplication.BaseLogoutListener(
+                            it,
+                            getString(R.string.invalid_login_message),
+                            username
+                        )
+                    }
+
+                    if (logoutListener != null) {
+                        CommonsApplication.instance.clearApplicationData(
+                            requireActivity(), logoutListener
+                        )
+                    }
+                }
+            }
+
+            override fun disableButtons() {
+                this@ReviewImageFragment.disableButtons()
+            }
+
+            override fun enableButtons() {
+                this@ReviewImageFragment.enableButtons()
+            }
+        }
+
+    /**
+     * This function is called when an image has
+     * been loaded to enable the review buttons.
+     */
+    fun enableButtons() {
+        binding?.apply {
+            buttonYes.isEnabled = true
+            buttonYes.alpha = 1f
+            buttonNo.isEnabled = true
+            buttonNo.alpha = 1f
+        }
+    }
+
+    /**
+     * This function is called when an image is being loaded
+     * to disable the review buttons
+     */
+    fun disableButtons() {
+        binding?.apply {
+            buttonYes.isEnabled = false
+            buttonYes.alpha = 0.5f
+            buttonNo.isEnabled = false
+            buttonNo.alpha = 0.5f
+        }
+    }
+
+    fun onYesButtonClicked() {
+        reviewActivity.swipeToNext()
+    }
+
+    private val reviewActivity: ReviewActivity
+        get() = requireActivity() as ReviewActivity
+
+    override fun onDestroy() {
+        super.onDestroy()
+        binding = null
+    }
+}

app/src/main/java/fr/free/nrw/commons/review/ReviewPagerAdapter.java

@@ -1,53 +0,0 @@
-package fr.free.nrw.commons.review;
-
-import android.os.Bundle;
-
-import android.view.ViewGroup;
-import androidx.annotation.NonNull;
-import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentManager;
-import androidx.fragment.app.FragmentStatePagerAdapter;
-
-public class ReviewPagerAdapter extends FragmentStatePagerAdapter {
-    private ReviewImageFragment[] reviewImageFragments;
-
-    /**
-     * this function return the instance of ReviewviewPage current item
-     */
-    @Override
-    public Object instantiateItem(@NonNull ViewGroup container, int position) {
-        return super.instantiateItem(container, position);
-    }
-
-    ReviewPagerAdapter(FragmentManager fm) {
-        super(fm);
-        reviewImageFragments = new ReviewImageFragment[]{
-                new ReviewImageFragment(),
-                new ReviewImageFragment(),
-                new ReviewImageFragment(),
-                new ReviewImageFragment()
-        };
-    }
-
-    @Override
-    public int getCount() {
-        return reviewImageFragments.length;
-    }
-
-    void updateFileInformation() {
-        for (int i = 0; i < getCount(); i++) {
-            ReviewImageFragment fragment = reviewImageFragments[i];
-            fragment.update(i);
-        }
-    }
-
-
-    @Override
-    public Fragment getItem(int position) {
-        Bundle bundle = new Bundle();
-        bundle.putInt("position", position);
-        reviewImageFragments[position].setArguments(bundle);
-        return reviewImageFragments[position];
-    }
-
-}

app/src/main/java/fr/free/nrw/commons/review/ReviewPagerAdapter.kt

@@ -0,0 +1,37 @@
+package fr.free.nrw.commons.review
+
+import android.os.Bundle
+
+import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentManager
+import androidx.fragment.app.FragmentStatePagerAdapter
+
+
+class ReviewPagerAdapter(fm: FragmentManager) : FragmentStatePagerAdapter(fm) {
+    private val reviewImageFragments: Array<ReviewImageFragment> = arrayOf(
+        ReviewImageFragment(),
+        ReviewImageFragment(),
+        ReviewImageFragment(),
+        ReviewImageFragment()
+    )
+
+    override fun getCount(): Int {
+        return reviewImageFragments.size
+    }
+
+    fun updateFileInformation() {
+        for (i in 0 until count) {
+            val fragment = reviewImageFragments[i]
+            fragment.update(i)
+        }
+    }
+
+    override fun getItem(position: Int): Fragment {
+        val bundle = Bundle().apply {
+            putInt("position", position)
+        }
+        reviewImageFragments[position].arguments = bundle
+        return reviewImageFragments[position]
+    }
+}

app/src/main/java/fr/free/nrw/commons/review/ReviewViewPager.java

@@ -1,30 +0,0 @@
-package fr.free.nrw.commons.review;
-
-import android.content.Context;
-import android.util.AttributeSet;
-import android.view.MotionEvent;
-
-import androidx.viewpager.widget.ViewPager;
-
-public class ReviewViewPager extends ViewPager {
-
-    public ReviewViewPager(Context context) {
-        super(context);
-    }
-
-    public ReviewViewPager(Context context, AttributeSet attrs) {
-        super(context, attrs);
-    }
-
-    @Override
-    public boolean onInterceptTouchEvent(MotionEvent event) {
-        // Never allow swiping to switch between pages
-        return false;
-    }
-
-    @Override
-    public boolean onTouchEvent(MotionEvent event) {
-        // Never allow swiping to switch between pages
-        return false;
-    }
-}

app/src/main/java/fr/free/nrw/commons/review/ReviewViewPager.kt

@@ -0,0 +1,25 @@
+package fr.free.nrw.commons.review
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.util.AttributeSet
+import android.view.MotionEvent
+
+import androidx.viewpager.widget.ViewPager
+
+class ReviewViewPager @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null
+) : ViewPager(context, attrs) {
+
+    override fun onInterceptTouchEvent(event: MotionEvent): Boolean {
+        // Never allow swiping to switch between pages
+        return false
+    }
+
+    @SuppressLint("ClickableViewAccessibility")
+    override fun onTouchEvent(event: MotionEvent): Boolean {
+        // Never allow swiping to switch between pages
+        return false
+    }
+}

app/src/main/java/fr/free/nrw/commons/settings/Prefs.java

@@ -1,21 +0,0 @@
-package fr.free.nrw.commons.settings;
-
-public class Prefs {
-    public static String GLOBAL_PREFS = "fr.free.nrw.commons.preferences";
-
-    public static String TRACKING_ENABLED = "eventLogging";
-    public static final String DEFAULT_LICENSE = "defaultLicense";
-    public static final String UPLOADS_SHOWING = "uploadsshowing";
-    public static final String MANAGED_EXIF_TAGS = "managed_exif_tags";
-    public static final String DESCRIPTION_LANGUAGE = "languageDescription";
-    public static final String APP_UI_LANGUAGE = "appUiLanguage";
-    public static final String KEY_THEME_VALUE = "appThemePref";
-
-    public static class Licenses {
-        public static final String CC_BY_SA_3 = "CC BY-SA 3.0";
-        public static final String CC_BY_3 = "CC BY 3.0";
-        public static final String CC_BY_SA_4 = "CC BY-SA 4.0";
-        public static final String CC_BY_4 = "CC BY 4.0";
-        public static final String CC0 = "CC0";
-    }
-}

app/src/main/java/fr/free/nrw/commons/settings/Prefs.kt

@@ -0,0 +1,21 @@
+package fr.free.nrw.commons.settings
+
+object Prefs {
+    const val GLOBAL_PREFS = "fr.free.nrw.commons.preferences"
+
+    const val TRACKING_ENABLED = "eventLogging"
+    const val DEFAULT_LICENSE = "defaultLicense"
+    const val UPLOADS_SHOWING = "uploadsShowing"
+    const val MANAGED_EXIF_TAGS = "managed_exif_tags"
+    const val DESCRIPTION_LANGUAGE = "languageDescription"
+    const val APP_UI_LANGUAGE = "appUiLanguage"
+    const val KEY_THEME_VALUE = "appThemePref"
+
+    object Licenses {
+        const val CC_BY_SA_3 = "CC BY-SA 3.0"
+        const val CC_BY_3 = "CC BY 3.0"
+        const val CC_BY_SA_4 = "CC BY-SA 4.0"
+        const val CC_BY_4 = "CC BY 4.0"
+        const val CC0 = "CC0"
+    }
+}

app/src/main/java/fr/free/nrw/commons/settings/SettingsActivity.java

@@ -1,69 +0,0 @@
-package fr.free.nrw.commons.settings;
-
-import android.os.Bundle;
-import android.view.MenuItem;
-
-import android.view.View;
-import androidx.appcompat.app.AppCompatDelegate;
-
-import fr.free.nrw.commons.databinding.ActivitySettingsBinding;
-import fr.free.nrw.commons.theme.BaseActivity;
-
-/**
- * allows the user to change the settings
- */
-public class SettingsActivity extends BaseActivity {
-
-    private ActivitySettingsBinding binding;
-//    private AppCompatDelegate settingsDelegate;
-    /**
-     * to be called when the activity starts
-     * @param savedInstanceState the previously saved state
-     */
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        binding = ActivitySettingsBinding.inflate(getLayoutInflater());
-        final View view = binding.getRoot();
-        setContentView(view);
-
-        setSupportActionBar(binding.toolbarBinding.toolbar);
-        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-    }
-
-    // Get an action bar
-    /**
-     * takes care of actions taken after the creation has happened
-     * @param savedInstanceState the saved state
-     */
-    @Override
-    protected void onPostCreate(Bundle savedInstanceState) {
-        super.onPostCreate(savedInstanceState);
-//        if (settingsDelegate == null) {
-//            settingsDelegate = AppCompatDelegate.create(this, null);
-//        }
-//        settingsDelegate.onPostCreate(savedInstanceState);
-    }
-
-    @Override
-    public boolean onSupportNavigateUp() {
-        onBackPressed();
-        return true;
-    }
-
-    /**
-     * Handle action-bar clicks
-     * @param item the selected item
-     * @return true on success, false on failure
-     */
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case android.R.id.home:
-                finish();
-                return true;
-            default:
-                return super.onOptionsItemSelected(item);
-        }
-    }
-}

app/src/main/java/fr/free/nrw/commons/settings/SettingsActivity.kt

@@ -0,0 +1,63 @@
+package fr.free.nrw.commons.settings
+
+import android.os.Bundle
+import android.view.MenuItem
+import fr.free.nrw.commons.databinding.ActivitySettingsBinding
+import fr.free.nrw.commons.theme.BaseActivity
+
+
+/**
+ * allows the user to change the settings
+ */
+class SettingsActivity : BaseActivity() {
+
+    private lateinit var binding: ActivitySettingsBinding
+//    private var settingsDelegate: AppCompatDelegate? = null
+
+    /**
+     * to be called when the activity starts
+     * @param savedInstanceState the previously saved state
+     */
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = ActivitySettingsBinding.inflate(layoutInflater)
+        val view = binding.root
+        setContentView(view)
+
+        setSupportActionBar(binding.toolbarBinding.toolbar)
+        supportActionBar?.setDisplayHomeAsUpEnabled(true)
+    }
+
+    // Get an action bar
+    /**
+     * takes care of actions taken after the creation has happened
+     * @param savedInstanceState the saved state
+     */
+    override fun onPostCreate(savedInstanceState: Bundle?) {
+        super.onPostCreate(savedInstanceState)
+//        if (settingsDelegate == null) {
+//            settingsDelegate = AppCompatDelegate.create(this, null)
+//        }
+//        settingsDelegate?.onPostCreate(savedInstanceState)
+    }
+
+    override fun onSupportNavigateUp(): Boolean {
+        onBackPressed()
+        return true
+    }
+
+    /**
+     * Handle action-bar clicks
+     * @param item the selected item
+     * @return true on success, false on failure
+     */
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        return when (item.itemId) {
+            android.R.id.home -> {
+                finish()
+                true
+            }
+            else -> super.onOptionsItemSelected(item)
+        }
+    }
+}

app/src/main/java/fr/free/nrw/commons/settings/SettingsFragment.java

@@ -1,561 +0,0 @@
-package fr.free.nrw.commons.settings;
-
-import static android.content.Context.MODE_PRIVATE;
-
-import android.Manifest.permission;
-import android.app.Activity;
-import android.app.Dialog;
-import android.content.Intent;
-import android.content.SharedPreferences;
-import android.content.res.Configuration;
-import android.net.Uri;
-import android.os.Bundle;
-import android.text.Editable;
-import android.text.TextWatcher;
-import android.view.View;
-import android.widget.AdapterView;
-import android.widget.AdapterView.OnItemClickListener;
-import android.widget.EditText;
-import android.widget.ListView;
-import android.widget.TextView;
-import androidx.activity.result.ActivityResultCallback;
-import androidx.activity.result.ActivityResultLauncher;
-import androidx.activity.result.contract.ActivityResultContracts;
-import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult;
-import androidx.preference.ListPreference;
-import androidx.preference.MultiSelectListPreference;
-import androidx.preference.Preference;
-import androidx.preference.Preference.OnPreferenceClickListener;
-import androidx.preference.PreferenceFragmentCompat;
-import androidx.preference.PreferenceGroupAdapter;
-import androidx.preference.PreferenceScreen;
-import androidx.preference.PreferenceViewHolder;
-import androidx.recyclerview.widget.RecyclerView.Adapter;
-import com.karumi.dexter.Dexter;
-import com.karumi.dexter.MultiplePermissionsReport;
-import com.karumi.dexter.PermissionToken;
-import com.karumi.dexter.listener.PermissionRequest;
-import com.karumi.dexter.listener.multi.MultiplePermissionsListener;
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.Utils;
-import fr.free.nrw.commons.campaigns.CampaignView;
-import fr.free.nrw.commons.contributions.ContributionController;
-import fr.free.nrw.commons.contributions.MainActivity;
-import fr.free.nrw.commons.di.ApplicationlessInjection;
-import fr.free.nrw.commons.kvstore.JsonKvStore;
-import fr.free.nrw.commons.location.LocationServiceManager;
-import fr.free.nrw.commons.logging.CommonsLogSender;
-import fr.free.nrw.commons.recentlanguages.Language;
-import fr.free.nrw.commons.recentlanguages.RecentLanguagesAdapter;
-import fr.free.nrw.commons.recentlanguages.RecentLanguagesDao;
-import fr.free.nrw.commons.upload.LanguagesAdapter;
-import fr.free.nrw.commons.utils.DialogUtil;
-import fr.free.nrw.commons.utils.PermissionUtils;
-import fr.free.nrw.commons.utils.ViewUtil;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
-import javax.inject.Inject;
-import javax.inject.Named;
-
-public class SettingsFragment extends PreferenceFragmentCompat {
-
-    @Inject
-    @Named("default_preferences")
-    JsonKvStore defaultKvStore;
-
-    @Inject
-    CommonsLogSender commonsLogSender;
-
-    @Inject
-    RecentLanguagesDao recentLanguagesDao;
-
-    @Inject
-    ContributionController contributionController;
-
-    @Inject
-    LocationServiceManager locationManager;
-
-    private ListPreference themeListPreference;
-    private Preference descriptionLanguageListPreference;
-    private Preference appUiLanguageListPreference;
-    private String keyLanguageListPreference;
-    private TextView recentLanguagesTextView;
-    private View separator;
-    private ListView languageHistoryListView;
-    private static final String GET_CONTENT_PICKER_HELP_URL = "https://commons-app.github.io/docs.html#get-content";
-
-    private final ActivityResultLauncher<Intent> cameraPickLauncherForResult =
-        registerForActivityResult(new StartActivityForResult(),
-        result -> {
-            contributionController.handleActivityResultWithCallback(requireActivity(), callbacks -> {
-                contributionController.onPictureReturnedFromCamera(result, requireActivity(), callbacks);
-            });
-        });
-
-    private ActivityResultLauncher<String[]> inAppCameraLocationPermissionLauncher = registerForActivityResult(new ActivityResultContracts.RequestMultiplePermissions(), new ActivityResultCallback<Map<String, Boolean>>() {
-        @Override
-        public void onActivityResult(Map<String, Boolean> result) {
-            boolean areAllGranted = true;
-            for (final boolean b : result.values()) {
-                areAllGranted = areAllGranted && b;
-            }
-            if (!areAllGranted && shouldShowRequestPermissionRationale(permission.ACCESS_FINE_LOCATION)) {
-                contributionController.handleShowRationaleFlowCameraLocation(getActivity(), inAppCameraLocationPermissionLauncher, cameraPickLauncherForResult);
-            }
-        }
-    });
-
-    @Override
-    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
-        ApplicationlessInjection
-            .getInstance(getActivity().getApplicationContext())
-            .getCommonsApplicationComponent()
-            .inject(this);
-
-        // Set the preferences from an XML resource
-        setPreferencesFromResource(R.xml.preferences, rootKey);
-
-        themeListPreference = findPreference(Prefs.KEY_THEME_VALUE);
-        prepareTheme();
-
-        MultiSelectListPreference multiSelectListPref = findPreference(Prefs.MANAGED_EXIF_TAGS);
-        if (multiSelectListPref != null) {
-            multiSelectListPref.setOnPreferenceChangeListener((preference, newValue) -> {
-                if (newValue instanceof HashSet && !((HashSet) newValue).contains(getString(R.string.exif_tag_location))) {
-                    defaultKvStore.putBoolean("has_user_manually_removed_location", true);
-                }
-                return true;
-            });
-        }
-
-        Preference inAppCameraLocationPref = findPreference("inAppCameraLocationPref");
-
-        inAppCameraLocationPref.setOnPreferenceChangeListener(
-            (preference, newValue) -> {
-                boolean isInAppCameraLocationTurnedOn = (boolean) newValue;
-                if (isInAppCameraLocationTurnedOn) {
-                    createDialogsAndHandleLocationPermissions(getActivity());
-                }
-                return true;
-            }
-        );
-
-        // Gets current language code from shared preferences
-        String languageCode;
-
-        appUiLanguageListPreference = findPreference("appUiDefaultLanguagePref");
-        assert appUiLanguageListPreference != null;
-        keyLanguageListPreference = appUiLanguageListPreference.getKey();
-        languageCode = getCurrentLanguageCode(keyLanguageListPreference);
-        assert languageCode != null;
-        if (languageCode.equals("")) {
-            // If current language code is empty, means none selected by user yet so use phone local
-            appUiLanguageListPreference.setSummary(Locale.getDefault().getDisplayLanguage());
-        } else {
-            // If any language is selected by user previously, use it
-            Locale defLocale = createLocale(languageCode);
-            appUiLanguageListPreference.setSummary((defLocale).getDisplayLanguage(defLocale));
-        }
-        appUiLanguageListPreference.setOnPreferenceClickListener(new OnPreferenceClickListener() {
-            @Override
-            public boolean onPreferenceClick(Preference preference) {
-                prepareAppLanguages(appUiLanguageListPreference.getKey());
-                return true;
-            }
-        });
-
-        descriptionLanguageListPreference = findPreference("descriptionDefaultLanguagePref");
-        assert descriptionLanguageListPreference != null;
-        keyLanguageListPreference = descriptionLanguageListPreference.getKey();
-        languageCode = getCurrentLanguageCode(keyLanguageListPreference);
-        assert languageCode != null;
-        if (languageCode.equals("")) {
-            // If current language code is empty, means none selected by user yet so use phone local
-            descriptionLanguageListPreference.setSummary(Locale.getDefault().getDisplayLanguage());
-        } else {
-            // If any language is selected by user previously, use it
-            Locale defLocale = createLocale(languageCode);
-            descriptionLanguageListPreference.setSummary(defLocale.getDisplayLanguage(defLocale));
-        }
-        descriptionLanguageListPreference.setOnPreferenceClickListener(new OnPreferenceClickListener() {
-            @Override
-            public boolean onPreferenceClick(Preference preference) {
-                prepareAppLanguages(descriptionLanguageListPreference.getKey());
-                return true;
-            }
-        });
-
-        Preference betaTesterPreference = findPreference("becomeBetaTester");
-        betaTesterPreference.setOnPreferenceClickListener(preference -> {
-            Utils.handleWebUrl(getActivity(), Uri.parse(getResources().getString(R.string.beta_opt_in_link)));
-            return true;
-        });
-        Preference sendLogsPreference = findPreference("sendLogFile");
-        sendLogsPreference.setOnPreferenceClickListener(preference -> {
-            checkPermissionsAndSendLogs();
-            return true;
-        });
-
-        Preference documentBasedPickerPreference = findPreference("openDocumentPhotoPickerPref");
-        documentBasedPickerPreference.setOnPreferenceChangeListener(
-            (preference, newValue) -> {
-                boolean isGetContentPickerTurnedOn = !(boolean) newValue;
-                if (isGetContentPickerTurnedOn) {
-                    showLocationLossWarning();
-                }
-                return true;
-            }
-        );
-        // Disable some settings when not logged in.
-        if (defaultKvStore.getBoolean("login_skipped", false)) {
-            findPreference("useExternalStorage").setEnabled(false);
-            findPreference("useAuthorName").setEnabled(false);
-            findPreference("displayNearbyCardView").setEnabled(false);
-            findPreference("descriptionDefaultLanguagePref").setEnabled(false);
-            findPreference("displayLocationPermissionForCardView").setEnabled(false);
-            findPreference(CampaignView.CAMPAIGNS_DEFAULT_PREFERENCE).setEnabled(false);
-            findPreference("managed_exif_tags").setEnabled(false);
-            findPreference("openDocumentPhotoPickerPref").setEnabled(false);
-            findPreference("inAppCameraLocationPref").setEnabled(false);
-        }
-    }
-
-    /**
-     * Asks users to provide location access
-     *
-     * @param activity
-     */
-    private void createDialogsAndHandleLocationPermissions(Activity activity) {
-        inAppCameraLocationPermissionLauncher.launch(new String[]{permission.ACCESS_FINE_LOCATION});
-    }
-
-    /**
-     * On some devices, the new Photo Picker with GET_CONTENT takeover
-     * redacts location tags from EXIF metadata
-     *
-     * Show warning to the user when ACTION_GET_CONTENT intent is enabled
-     */
-    private void showLocationLossWarning() {
-        DialogUtil.showAlertDialog(
-            getActivity(),
-            null,
-            getString(R.string.location_loss_warning),
-            getString(R.string.ok),
-            getString(R.string.read_help_link),
-            () -> {},
-            () -> Utils.handleWebUrl(requireContext(), Uri.parse(GET_CONTENT_PICKER_HELP_URL)),
-            null,
-            true
-        );
-    }
-
-    @Override
-    protected Adapter onCreateAdapter(final PreferenceScreen preferenceScreen) {
-        return new PreferenceGroupAdapter(preferenceScreen) {
-            @Override
-            public void onBindViewHolder(PreferenceViewHolder holder, int position) {
-                super.onBindViewHolder(holder, position);
-                Preference preference = getItem(position);
-                View iconFrame = holder.itemView.findViewById(R.id.icon_frame);
-                if (iconFrame != null) {
-                    iconFrame.setVisibility(View.GONE);
-                }
-            }
-        };
-    }
-
-    /**
-     * Sets the theme pref
-     */
-    private void prepareTheme() {
-        themeListPreference.setOnPreferenceChangeListener((preference, newValue) -> {
-            getActivity().recreate();
-            return true;
-        });
-    }
-
-    /**
-     * Prepare and Show language selection dialog box
-     * Uses previously saved language if there is any, if not uses phone locale as initial language.
-     * Disable default/already selected language from dialog box
-     * Get ListPreference key and act accordingly for each ListPreference.
-     * saves value chosen by user to shared preferences
-     * to remember later and recall MainActivity to reflect language changes
-     * @param keyListPreference
-     */
-    private void prepareAppLanguages(final String keyListPreference) {
-
-        // Gets current language code from shared preferences
-        final String languageCode = getCurrentLanguageCode(keyListPreference);
-        final List<Language> recentLanguages = recentLanguagesDao.getRecentLanguages();
-        HashMap<Integer, String> selectedLanguages = new HashMap<>();
-
-        if (keyListPreference.equals("appUiDefaultLanguagePref")) {
-
-            assert languageCode != null;
-            if (languageCode.equals("")) {
-                selectedLanguages.put(0, Locale.getDefault().getLanguage());
-            } else {
-                selectedLanguages.put(0, languageCode);
-            }
-        } else if (keyListPreference.equals("descriptionDefaultLanguagePref")) {
-
-            assert languageCode != null;
-            if (languageCode.equals("")) {
-                selectedLanguages.put(0, Locale.getDefault().getLanguage());
-
-            } else {
-                selectedLanguages.put(0, languageCode);
-            }
-        }
-
-        LanguagesAdapter languagesAdapter = new LanguagesAdapter(
-            getActivity(),
-            selectedLanguages
-        );
-
-        Dialog dialog = new Dialog(getActivity());
-        dialog.setContentView(R.layout.dialog_select_language);
-        dialog.setCanceledOnTouchOutside(true);
-        dialog.getWindow().setLayout((int)(getActivity().getResources().getDisplayMetrics().widthPixels*0.90),
-            (int)(getActivity().getResources().getDisplayMetrics().heightPixels*0.90));
-        dialog.show();
-
-        EditText editText = dialog.findViewById(R.id.search_language);
-        ListView listView = dialog.findViewById(R.id.language_list);
-        languageHistoryListView = dialog.findViewById(R.id.language_history_list);
-        recentLanguagesTextView = dialog.findViewById(R.id.recent_searches);
-        separator = dialog.findViewById(R.id.separator);
-
-        setUpRecentLanguagesSection(recentLanguages, selectedLanguages);
-
-        listView.setAdapter(languagesAdapter);
-
-        editText.addTextChangedListener(new TextWatcher() {
-            @Override
-            public void beforeTextChanged(CharSequence charSequence, int i, int i1,
-                int i2) {
-                hideRecentLanguagesSection();
-            }
-
-            @Override
-            public void onTextChanged(CharSequence charSequence, int i, int i1,
-                int i2) {
-                languagesAdapter.getFilter().filter(charSequence);
-            }
-
-            @Override
-            public void afterTextChanged(Editable editable) {
-
-            }
-        });
-
-        languageHistoryListView.setOnItemClickListener((adapterView, view, position, id) -> {
-            onRecentLanguageClicked(keyListPreference, dialog, adapterView, position);
-        });
-
-        listView.setOnItemClickListener(new OnItemClickListener() {
-            @Override
-            public void onItemClick(AdapterView<?> adapterView, View view, int i,
-                long l) {
-                String languageCode = ((LanguagesAdapter) adapterView.getAdapter())
-                    .getLanguageCode(i);
-                final String languageName = ((LanguagesAdapter) adapterView.getAdapter())
-                    .getLanguageName(i);
-                final boolean isExists = recentLanguagesDao.findRecentLanguage(languageCode);
-                if (isExists) {
-                    recentLanguagesDao.deleteRecentLanguage(languageCode);
-                }
-                recentLanguagesDao.addRecentLanguage(new Language(languageName, languageCode));
-                saveLanguageValue(languageCode, keyListPreference);
-                Locale defLocale = createLocale(languageCode);
-                if(keyListPreference.equals("appUiDefaultLanguagePref")) {
-                    appUiLanguageListPreference.setSummary(defLocale.getDisplayLanguage(defLocale));
-                    setLocale(requireActivity(), languageCode);
-                    getActivity().recreate();
-                    final Intent intent = new Intent(getActivity(), MainActivity.class);
-                    startActivity(intent);
-                }else {
-                    descriptionLanguageListPreference.setSummary(defLocale.getDisplayLanguage(defLocale));
-                }
-                dialog.dismiss();
-            }
-        });
-
-        dialog.setOnDismissListener(
-            dialogInterface -> languagesAdapter.getFilter().filter(""));
-    }
-
-    /**
-     * Set up recent languages section
-     *
-     * @param recentLanguages recently used languages
-     * @param selectedLanguages selected languages
-     */
-    private void setUpRecentLanguagesSection(List<Language> recentLanguages,
-        HashMap<Integer, String> selectedLanguages) {
-        if (recentLanguages.isEmpty()) {
-            languageHistoryListView.setVisibility(View.GONE);
-            recentLanguagesTextView.setVisibility(View.GONE);
-            separator.setVisibility(View.GONE);
-        } else {
-            if (recentLanguages.size() > 5) {
-                for (int i = recentLanguages.size()-1; i >=5; i--) {
-                    recentLanguagesDao
-                        .deleteRecentLanguage(recentLanguages.get(i).getLanguageCode());
-                }
-            }
-            languageHistoryListView.setVisibility(View.VISIBLE);
-            recentLanguagesTextView.setVisibility(View.VISIBLE);
-            separator.setVisibility(View.VISIBLE);
-            final RecentLanguagesAdapter recentLanguagesAdapter
-                = new RecentLanguagesAdapter(
-                getActivity(),
-                recentLanguagesDao.getRecentLanguages(),
-                selectedLanguages);
-            languageHistoryListView.setAdapter(recentLanguagesAdapter);
-        }
-    }
-
-    /**
-     * Handles click event for recent language section
-     */
-    private void onRecentLanguageClicked(String keyListPreference, Dialog dialog, AdapterView<?> adapterView,
-        int position) {
-        final String recentLanguageCode = ((RecentLanguagesAdapter) adapterView.getAdapter())
-            .getLanguageCode(position);
-        final String recentLanguageName = ((RecentLanguagesAdapter) adapterView.getAdapter())
-            .getLanguageName(position);
-        final boolean isExists = recentLanguagesDao.findRecentLanguage(recentLanguageCode);
-        if (isExists) {
-            recentLanguagesDao.deleteRecentLanguage(recentLanguageCode);
-        }
-        recentLanguagesDao.addRecentLanguage(
-            new Language(recentLanguageName, recentLanguageCode));
-        saveLanguageValue(recentLanguageCode, keyListPreference);
-        final Locale defLocale = createLocale(recentLanguageCode);
-        if (keyListPreference.equals("appUiDefaultLanguagePref")) {
-            appUiLanguageListPreference.setSummary(defLocale.getDisplayLanguage(defLocale));
-            setLocale(requireActivity(), recentLanguageCode);
-            getActivity().recreate();
-            final Intent intent = new Intent(getActivity(), MainActivity.class);
-            startActivity(intent);
-        } else {
-            descriptionLanguageListPreference.setSummary(defLocale.getDisplayLanguage(defLocale));
-        }
-        dialog.dismiss();
-    }
-
-    /**
-     * Remove the section of recent languages
-     */
-    private void hideRecentLanguagesSection() {
-        languageHistoryListView.setVisibility(View.GONE);
-        recentLanguagesTextView.setVisibility(View.GONE);
-        separator.setVisibility(View.GONE);
-    }
-
-    /**
-     * Changing the default app language with selected one and save it to SharedPreferences
-     */
-    public void setLocale(final Activity activity, String userSelectedValue) {
-        if (userSelectedValue.equals("")) {
-            userSelectedValue = Locale.getDefault().getLanguage();
-        }
-        final Locale locale = createLocale(userSelectedValue);
-        Locale.setDefault(locale);
-        final Configuration configuration = new Configuration();
-        configuration.locale = locale;
-        activity.getBaseContext().getResources().updateConfiguration(configuration,
-            activity.getBaseContext().getResources().getDisplayMetrics());
-
-        final SharedPreferences.Editor editor = activity.getSharedPreferences("Settings", MODE_PRIVATE).edit();
-        editor.putString("language", userSelectedValue);
-        editor.apply();
-    }
-
-    /**
-     * Create Locale based on different types of language codes
-     * @param languageCode
-     * @return Locale and throws error for invalid language codes
-     */
-    public static Locale createLocale(String languageCode) {
-        String[] parts = languageCode.split("-");
-        switch (parts.length) {
-            case 1:
-                return new Locale(parts[0]);
-            case 2:
-                return new Locale(parts[0], parts[1]);
-            case 3:
-                return new Locale(parts[0], parts[1], parts[2]);
-            default:
-                throw new IllegalArgumentException("Invalid language code: " + languageCode);
-        }
-    }
-
-    /**
-     * Save userselected language in List Preference
-     * @param userSelectedValue
-     * @param preferenceKey
-     */
-    private void saveLanguageValue(final String userSelectedValue, final String preferenceKey) {
-        if (preferenceKey.equals("appUiDefaultLanguagePref")) {
-            defaultKvStore.putString(Prefs.APP_UI_LANGUAGE, userSelectedValue);
-        } else if (preferenceKey.equals("descriptionDefaultLanguagePref")) {
-            defaultKvStore.putString(Prefs.DESCRIPTION_LANGUAGE, userSelectedValue);
-        }
-    }
-
-    /**
-     * Gets current language code from shared preferences
-     * @param preferenceKey
-     * @return
-     */
-    private String getCurrentLanguageCode(final String preferenceKey) {
-        if (preferenceKey.equals("appUiDefaultLanguagePref")) {
-            return defaultKvStore.getString(Prefs.APP_UI_LANGUAGE, "");
-        }
-        if (preferenceKey.equals("descriptionDefaultLanguagePref")) {
-            return defaultKvStore.getString(Prefs.DESCRIPTION_LANGUAGE, "");
-        }
-        return null;
-    }
-
-    /**
-     * First checks for external storage permissions and then sends logs via email
-     */
-    private void checkPermissionsAndSendLogs() {
-        if (PermissionUtils.hasPermission(getActivity(), PermissionUtils.PERMISSIONS_STORAGE)) {
-            commonsLogSender.send(getActivity(), null);
-        } else {
-            requestExternalStoragePermissions();
-        }
-    }
-
-    /**
-     * Requests external storage permissions and shows a toast stating that log collection has
-     * started
-     */
-    private void requestExternalStoragePermissions() {
-        Dexter.withActivity(getActivity())
-            .withPermissions(PermissionUtils.PERMISSIONS_STORAGE)
-            .withListener(new MultiplePermissionsListener() {
-                @Override
-                public void onPermissionsChecked(MultiplePermissionsReport report) {
-                    ViewUtil.showLongToast(getActivity(),
-                        getResources().getString(R.string.log_collection_started));
-                }
-
-                @Override
-                public void onPermissionRationaleShouldBeShown(
-                    List<PermissionRequest> permissions, PermissionToken token) {
-
-                }
-            })
-            .onSameThread()
-            .check();
-    }
-}

app/src/main/java/fr/free/nrw/commons/settings/SettingsFragment.kt

@@ -0,0 +1,558 @@
+package fr.free.nrw.commons.settings
+
+import android.Manifest.permission
+import android.app.Activity
+import android.app.Dialog
+import android.content.Context.MODE_PRIVATE
+import android.content.Intent
+import android.content.res.Configuration
+import android.net.Uri
+import android.os.Bundle
+import android.text.Editable
+import android.text.TextWatcher
+import android.view.View
+import android.widget.AdapterView
+import android.widget.EditText
+import android.widget.ListView
+import android.widget.TextView
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.contract.ActivityResultContracts.RequestMultiplePermissions
+import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult
+import androidx.preference.ListPreference
+import androidx.preference.MultiSelectListPreference
+import androidx.preference.Preference
+import androidx.preference.PreferenceFragmentCompat
+import androidx.preference.PreferenceGroupAdapter
+import androidx.preference.PreferenceScreen
+import androidx.preference.PreferenceViewHolder
+import androidx.recyclerview.widget.RecyclerView.Adapter
+import com.karumi.dexter.Dexter
+import com.karumi.dexter.MultiplePermissionsReport
+import com.karumi.dexter.PermissionToken
+import com.karumi.dexter.listener.PermissionRequest
+import com.karumi.dexter.listener.multi.MultiplePermissionsListener
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.Utils
+import fr.free.nrw.commons.campaigns.CampaignView
+import fr.free.nrw.commons.contributions.ContributionController
+import fr.free.nrw.commons.contributions.MainActivity
+import fr.free.nrw.commons.di.ApplicationlessInjection
+import fr.free.nrw.commons.kvstore.JsonKvStore
+import fr.free.nrw.commons.location.LocationServiceManager
+import fr.free.nrw.commons.logging.CommonsLogSender
+import fr.free.nrw.commons.recentlanguages.Language
+import fr.free.nrw.commons.recentlanguages.RecentLanguagesAdapter
+import fr.free.nrw.commons.recentlanguages.RecentLanguagesDao
+import fr.free.nrw.commons.upload.LanguagesAdapter
+import fr.free.nrw.commons.utils.DialogUtil
+import fr.free.nrw.commons.utils.PermissionUtils
+import fr.free.nrw.commons.utils.ViewUtil
+import java.util.Locale
+import javax.inject.Inject
+import javax.inject.Named
+
+class SettingsFragment : PreferenceFragmentCompat() {
+
+    @Inject
+    @field: Named("default_preferences")
+    lateinit var defaultKvStore: JsonKvStore
+
+    @Inject
+    lateinit var commonsLogSender: CommonsLogSender
+
+    @Inject
+    lateinit var recentLanguagesDao: RecentLanguagesDao
+
+    @Inject
+    lateinit var contributionController: ContributionController
+
+    @Inject
+    lateinit var locationManager: LocationServiceManager
+
+    private var themeListPreference: ListPreference? = null
+    private var descriptionLanguageListPreference: Preference? = null
+    private var appUiLanguageListPreference: Preference? = null
+    private var showDeletionButtonPreference: Preference? = null
+    private var keyLanguageListPreference: String? = null
+    private var recentLanguagesTextView: TextView? = null
+    private var separator: View? = null
+    private var languageHistoryListView: ListView? = null
+    private lateinit var inAppCameraLocationPermissionLauncher: ActivityResultLauncher<Array<String>>
+    private val GET_CONTENT_PICKER_HELP_URL = "https://commons-app.github.io/docs.html#get-content"
+
+    private val cameraPickLauncherForResult: ActivityResultLauncher<Intent> =
+        registerForActivityResult(StartActivityForResult()) { result ->
+        contributionController.handleActivityResultWithCallback(requireActivity()) { callbacks ->
+            contributionController.onPictureReturnedFromCamera(result, requireActivity(), callbacks)
+        }
+    }
+
+    /**
+     * to be called when the fragment creates preferences
+     * @param savedInstanceState the previously saved state
+     * @param rootKey the root key for preferences
+     */
+    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
+        ApplicationlessInjection
+            .getInstance(requireActivity().applicationContext)
+            .commonsApplicationComponent
+            .inject(this)
+
+        // Set the preferences from an XML resource
+        setPreferencesFromResource(R.xml.preferences, rootKey)
+
+        themeListPreference = findPreference(Prefs.KEY_THEME_VALUE)
+        prepareTheme()
+
+        val multiSelectListPref: MultiSelectListPreference? = findPreference(
+            Prefs.MANAGED_EXIF_TAGS
+        )
+        multiSelectListPref?.setOnPreferenceChangeListener { _, newValue ->
+            if (newValue is HashSet<*> && !newValue.contains(getString(R.string.exif_tag_location)))
+            {
+                defaultKvStore.putBoolean("has_user_manually_removed_location", true)
+            }
+            true
+        }
+
+        val inAppCameraLocationPref: Preference? = findPreference("inAppCameraLocationPref")
+        inAppCameraLocationPref?.setOnPreferenceChangeListener { _, newValue ->
+            val isInAppCameraLocationTurnedOn = newValue as Boolean
+            if (isInAppCameraLocationTurnedOn) {
+                createDialogsAndHandleLocationPermissions(requireActivity())
+            }
+            true
+        }
+
+        inAppCameraLocationPermissionLauncher = registerForActivityResult(
+            RequestMultiplePermissions()
+        ) { result ->
+            var areAllGranted = true
+            for (b in result.values) {
+                areAllGranted = areAllGranted && b
+            }
+            if (
+                !areAllGranted
+                    &&
+                shouldShowRequestPermissionRationale(permission.ACCESS_FINE_LOCATION)
+            ) {
+                contributionController.handleShowRationaleFlowCameraLocation(
+                    requireActivity(),
+                    inAppCameraLocationPermissionLauncher,
+                    cameraPickLauncherForResult
+                )
+            }
+        }
+
+        // Gets current language code from shared preferences
+        var languageCode: String?
+
+        appUiLanguageListPreference = findPreference("appUiDefaultLanguagePref")
+        appUiLanguageListPreference?.let { appUiLanguageListPreference ->
+            keyLanguageListPreference = appUiLanguageListPreference.key
+            languageCode = getCurrentLanguageCode(keyLanguageListPreference!!)
+
+            languageCode?.let { code ->
+                if (code.isEmpty()) {
+                    // If current language code is empty, means none selected by user yet so use
+                    // phone locale
+                    appUiLanguageListPreference.summary = Locale.getDefault().displayLanguage
+                } else {
+                    // If any language is selected by user previously, use it
+                    val defLocale = createLocale(code)
+                    appUiLanguageListPreference.summary = defLocale.getDisplayLanguage(defLocale)
+                }
+            }
+
+            appUiLanguageListPreference.setOnPreferenceClickListener {
+                prepareAppLanguages(keyLanguageListPreference!!)
+                true
+            }
+        }
+
+        descriptionLanguageListPreference = findPreference("descriptionDefaultLanguagePref")
+        descriptionLanguageListPreference?.let { descriptionLanguageListPreference ->
+            languageCode = getCurrentLanguageCode(descriptionLanguageListPreference.key)
+
+            languageCode?.let { code ->
+                if (code.isEmpty()) {
+                    // If current language code is empty, means none selected by user yet so use
+                    // phone locale
+                    descriptionLanguageListPreference.summary = Locale.getDefault().displayLanguage
+                } else {
+                    // If any language is selected by user previously, use it
+                    val defLocale = createLocale(code)
+                    descriptionLanguageListPreference.summary = defLocale.getDisplayLanguage(
+                        defLocale
+                    )
+                }
+            }
+
+            descriptionLanguageListPreference.setOnPreferenceClickListener {
+                prepareAppLanguages(it.key)
+                true
+            }
+        }
+
+        showDeletionButtonPreference = findPreference("displayDeletionButton")
+        showDeletionButtonPreference?.setOnPreferenceChangeListener { _, newValue ->
+            val isEnabled = newValue as Boolean
+            // Save preference when user toggles the button
+            defaultKvStore.putBoolean("displayDeletionButton", isEnabled)
+            true
+        }
+
+        val betaTesterPreference: Preference? = findPreference("becomeBetaTester")
+        betaTesterPreference?.setOnPreferenceClickListener {
+            Utils.handleWebUrl(requireActivity(), Uri.parse(getString(R.string.beta_opt_in_link)))
+            true
+        }
+
+        val sendLogsPreference: Preference? = findPreference("sendLogFile")
+        sendLogsPreference?.setOnPreferenceClickListener {
+            checkPermissionsAndSendLogs()
+            true
+        }
+
+        val documentBasedPickerPreference: Preference? = findPreference(
+            "openDocumentPhotoPickerPref"
+        )
+        documentBasedPickerPreference?.setOnPreferenceChangeListener { _, newValue ->
+            val isGetContentPickerTurnedOn = newValue as Boolean
+            if (!isGetContentPickerTurnedOn) {
+                showLocationLossWarning()
+            }
+            true
+        }
+
+        // Disable some settings when not logged in.
+        if (defaultKvStore.getBoolean("login_skipped", false)) {
+            findPreference<Preference>("useExternalStorage")?.isEnabled = false
+            findPreference<Preference>("useAuthorName")?.isEnabled = false
+            findPreference<Preference>("displayNearbyCardView")?.isEnabled = false
+            findPreference<Preference>("descriptionDefaultLanguagePref")?.isEnabled = false
+            findPreference<Preference>("displayLocationPermissionForCardView")?.isEnabled = false
+            findPreference<Preference>(CampaignView.CAMPAIGNS_DEFAULT_PREFERENCE)?.isEnabled = false
+            findPreference<Preference>("managed_exif_tags")?.isEnabled = false
+            findPreference<Preference>("openDocumentPhotoPickerPref")?.isEnabled = false
+            findPreference<Preference>("inAppCameraLocationPref")?.isEnabled = false
+        }
+    }
+
+    /**
+     * Asks users to provide location access
+     *
+     * @param activity
+     */
+    private fun createDialogsAndHandleLocationPermissions(activity: Activity) {
+        inAppCameraLocationPermissionLauncher.launch(arrayOf(permission.ACCESS_FINE_LOCATION))
+    }
+
+    /**
+     * On some devices, the new Photo Picker with GET_CONTENT takeover
+     * redacts location tags from EXIF metadata
+     *
+     * Show warning to the user when ACTION_GET_CONTENT intent is enabled
+     */
+    private fun showLocationLossWarning() {
+        DialogUtil.showAlertDialog(
+            requireActivity(),
+            null,
+            getString(R.string.location_loss_warning),
+            getString(R.string.ok),
+            getString(R.string.read_help_link),
+            { },
+            { Utils.handleWebUrl(requireContext(), Uri.parse(GET_CONTENT_PICKER_HELP_URL)) },
+            null,
+            true
+        )
+    }
+
+    override fun onCreateAdapter(preferenceScreen: PreferenceScreen): Adapter<PreferenceViewHolder>
+    {
+        return object : PreferenceGroupAdapter(preferenceScreen) {
+            override fun onBindViewHolder(holder: PreferenceViewHolder, position: Int) {
+                super.onBindViewHolder(holder, position)
+                val preference = getItem(position)
+                val iconFrame: View? = holder.itemView.findViewById(R.id.icon_frame)
+                iconFrame?.visibility = View.GONE
+            }
+        }
+    }
+
+    /**
+     * Sets the theme pref
+     */
+    private fun prepareTheme() {
+        themeListPreference?.setOnPreferenceChangeListener { _, _ ->
+            requireActivity().recreate()
+            true
+        }
+    }
+
+    /**
+     * Prepare and Show language selection dialog box
+     * Uses previously saved language if there is any, if not uses phone locale as initial language.
+     * Disable default/already selected language from dialog box
+     * Get ListPreference key and act accordingly for each ListPreference.
+     * saves value chosen by user to shared preferences
+     * to remember later and recall MainActivity to reflect language changes
+     * @param keyListPreference
+     */
+    private fun prepareAppLanguages(keyListPreference: String) {
+        // Gets current language code from shared preferences
+        val languageCode = getCurrentLanguageCode(keyListPreference)
+        val recentLanguages = recentLanguagesDao.getRecentLanguages()
+        val selectedLanguages = hashMapOf<Int, String>()
+
+        if (keyListPreference == "appUiDefaultLanguagePref") {
+            if (languageCode.isNullOrEmpty()) {
+                selectedLanguages[0] = Locale.getDefault().language
+            } else {
+                selectedLanguages[0] = languageCode
+            }
+        } else if (keyListPreference == "descriptionDefaultLanguagePref") {
+            if (languageCode.isNullOrEmpty()) {
+                selectedLanguages[0] = Locale.getDefault().language
+            } else {
+                selectedLanguages[0] = languageCode
+            }
+        }
+
+        val languagesAdapter = LanguagesAdapter(requireActivity(), selectedLanguages)
+
+        val dialog = Dialog(requireActivity())
+        dialog.setContentView(R.layout.dialog_select_language)
+        dialog.setCanceledOnTouchOutside(true)
+        dialog.window?.setLayout(
+            (resources.displayMetrics.widthPixels * 0.90).toInt(),
+            (resources.displayMetrics.heightPixels * 0.90).toInt()
+        )
+        dialog.show()
+
+        val editText: EditText = dialog.findViewById(R.id.search_language)
+        val listView: ListView = dialog.findViewById(R.id.language_list)
+        languageHistoryListView = dialog.findViewById(R.id.language_history_list)
+        recentLanguagesTextView = dialog.findViewById(R.id.recent_searches)
+        separator = dialog.findViewById(R.id.separator)
+
+        setUpRecentLanguagesSection(recentLanguages, selectedLanguages)
+
+        listView.adapter = languagesAdapter
+
+        editText.addTextChangedListener(object : TextWatcher {
+            override fun beforeTextChanged(charSequence: CharSequence, start: Int, count: Int, after: Int) {
+                hideRecentLanguagesSection()
+            }
+
+            override fun onTextChanged(charSequence: CharSequence, start: Int, before: Int, count: Int) {
+                languagesAdapter.filter.filter(charSequence)
+            }
+
+            override fun afterTextChanged(editable: Editable?) {}
+        })
+
+        languageHistoryListView?.setOnItemClickListener { adapterView, _, position, _ ->
+            onRecentLanguageClicked(keyListPreference, dialog, adapterView, position)
+        }
+
+        listView.setOnItemClickListener { adapterView, _, position, _ ->
+            val lCode = (adapterView.adapter as LanguagesAdapter).getLanguageCode(position)
+            val languageName = (adapterView.adapter as LanguagesAdapter).getLanguageName(position)
+            val isExists = recentLanguagesDao.findRecentLanguage(lCode)
+            if (isExists) {
+                recentLanguagesDao.deleteRecentLanguage(lCode)
+            }
+            recentLanguagesDao.addRecentLanguage(Language(languageName, lCode))
+            saveLanguageValue(lCode, keyListPreference)
+            val defLocale = createLocale(lCode)
+            if (keyListPreference == "appUiDefaultLanguagePref") {
+                appUiLanguageListPreference?.summary = defLocale.getDisplayLanguage(defLocale)
+                setLocale(requireActivity(), lCode)
+                requireActivity().recreate()
+                val intent = Intent(requireActivity(), MainActivity::class.java)
+                startActivity(intent)
+            } else {
+                descriptionLanguageListPreference?.summary = defLocale.getDisplayLanguage(defLocale)
+            }
+            dialog.dismiss()
+        }
+
+        dialog.setOnDismissListener { languagesAdapter.filter.filter("") }
+    }
+
+    /**
+     * Set up recent languages section
+     *
+     * @param recentLanguages recently used languages
+     * @param selectedLanguages selected languages
+     */
+    private fun setUpRecentLanguagesSection(
+        recentLanguages: List<Language>,
+        selectedLanguages: HashMap<Int, String>
+    ) {
+        if (recentLanguages.isEmpty()) {
+            languageHistoryListView?.visibility = View.GONE
+            recentLanguagesTextView?.visibility = View.GONE
+            separator?.visibility = View.GONE
+        } else {
+            if (recentLanguages.size > 5) {
+                for (i in recentLanguages.size - 1 downTo 5) {
+                    recentLanguagesDao.deleteRecentLanguage(recentLanguages[i].languageCode)
+                }
+            }
+            languageHistoryListView?.visibility = View.VISIBLE
+            recentLanguagesTextView?.visibility = View.VISIBLE
+            separator?.visibility = View.VISIBLE
+            val recentLanguagesAdapter = RecentLanguagesAdapter(
+                requireActivity(),
+                recentLanguagesDao.getRecentLanguages(),
+                selectedLanguages
+            )
+            languageHistoryListView?.adapter = recentLanguagesAdapter
+        }
+    }
+
+    /**
+     * Handles click event for recent language section
+     */
+    private fun onRecentLanguageClicked(
+        keyListPreference: String,
+        dialog: Dialog,
+        adapterView: AdapterView<*>,
+        position: Int
+    ) {
+        val recentLanguageCode = (adapterView.adapter as RecentLanguagesAdapter).getLanguageCode(position)
+        val recentLanguageName = (adapterView.adapter as RecentLanguagesAdapter).getLanguageName(position)
+        val isExists = recentLanguagesDao.findRecentLanguage(recentLanguageCode)
+        if (isExists) {
+            recentLanguagesDao.deleteRecentLanguage(recentLanguageCode)
+        }
+        recentLanguagesDao.addRecentLanguage(Language(recentLanguageName, recentLanguageCode))
+        saveLanguageValue(recentLanguageCode, keyListPreference)
+        val defLocale = createLocale(recentLanguageCode)
+        if (keyListPreference == "appUiDefaultLanguagePref") {
+            appUiLanguageListPreference?.summary = defLocale.getDisplayLanguage(defLocale)
+            setLocale(requireActivity(), recentLanguageCode)
+            requireActivity().recreate()
+            val intent = Intent(requireActivity(), MainActivity::class.java)
+            startActivity(intent)
+        } else {
+            descriptionLanguageListPreference?.summary = defLocale.getDisplayLanguage(defLocale)
+        }
+        dialog.dismiss()
+    }
+
+    /**
+     * Remove the section of recent languages
+     */
+    private fun hideRecentLanguagesSection() {
+        languageHistoryListView?.visibility = View.GONE
+        recentLanguagesTextView?.visibility = View.GONE
+        separator?.visibility = View.GONE
+    }
+
+    /**
+     * Changing the default app language with selected one and save it to SharedPreferences
+     */
+    fun setLocale(activity: Activity, userSelectedValue: String) {
+        var selectedLanguage = userSelectedValue
+        if (selectedLanguage == "") {
+            selectedLanguage = Locale.getDefault().language
+        }
+        val locale = createLocale(selectedLanguage)
+        Locale.setDefault(locale)
+        val configuration = Configuration()
+        configuration.locale = locale
+        activity.baseContext.resources.updateConfiguration(configuration, activity.baseContext.resources.displayMetrics)
+
+        val editor = activity.getSharedPreferences("Settings", MODE_PRIVATE).edit()
+        editor.putString("language", selectedLanguage)
+        editor.apply()
+    }
+
+    companion object {
+        /**
+         * Create Locale based on different types of language codes
+         * @param languageCode
+         * @return Locale and throws error for invalid language codes
+         */
+        fun createLocale(languageCode: String): Locale {
+            val parts = languageCode.split("-")
+            return when (parts.size) {
+                1 -> Locale(parts[0])
+                2 -> Locale(parts[0], parts[1])
+                3 -> Locale(parts[0], parts[1], parts[2])
+                else -> throw IllegalArgumentException("Invalid language code: $languageCode")
+            }
+        }
+    }
+
+    /**
+     * Save userSelected language in List Preference
+     * @param userSelectedValue
+     * @param preferenceKey
+     */
+    private fun saveLanguageValue(userSelectedValue: String, preferenceKey: String) {
+        when (preferenceKey) {
+            "appUiDefaultLanguagePref" -> defaultKvStore.putString(Prefs.APP_UI_LANGUAGE, userSelectedValue)
+            "descriptionDefaultLanguagePref" -> defaultKvStore.putString(Prefs.DESCRIPTION_LANGUAGE, userSelectedValue)
+        }
+    }
+
+    /**
+     * Gets current language code from shared preferences
+     * @param preferenceKey
+     * @return
+     */
+    private fun getCurrentLanguageCode(preferenceKey: String): String? {
+        return when (preferenceKey) {
+            "appUiDefaultLanguagePref" -> defaultKvStore.getString(
+                Prefs.APP_UI_LANGUAGE, ""
+            )
+            "descriptionDefaultLanguagePref" -> defaultKvStore.getString(
+                Prefs.DESCRIPTION_LANGUAGE, ""
+            )
+            else -> null
+        }
+    }
+
+    /**
+     * First checks for external storage permissions and then sends logs via email
+     */
+    private fun checkPermissionsAndSendLogs() {
+        if (
+            PermissionUtils.hasPermission(
+                requireActivity(),
+                PermissionUtils.PERMISSIONS_STORAGE
+            )
+        ) {
+            commonsLogSender.send(requireActivity(), null)
+        } else {
+            requestExternalStoragePermissions()
+        }
+    }
+
+    /**
+     * Requests external storage permissions and shows a toast stating that log collection has
+     * started
+     */
+    private fun requestExternalStoragePermissions() {
+        Dexter.withActivity(requireActivity())
+            .withPermissions(*PermissionUtils.PERMISSIONS_STORAGE)
+            .withListener(object : MultiplePermissionsListener {
+                override fun onPermissionsChecked(report: MultiplePermissionsReport) {
+                    ViewUtil.showLongToast(requireActivity(), getString(R.string.log_collection_started))
+                }
+
+                override fun onPermissionRationaleShouldBeShown(
+                    permissions: List<PermissionRequest>, token: PermissionToken
+                ) {
+                    // No action needed
+                }
+            })
+            .onSameThread()
+            .check()
+    }
+
+}

app/src/main/java/fr/free/nrw/commons/theme/BaseActivity.java

@@ -1,66 +0,0 @@
-package fr.free.nrw.commons.theme;
-
-import android.content.res.Configuration;
-import android.os.Bundle;
-import android.util.DisplayMetrics;
-import android.view.WindowManager;
-import javax.inject.Inject;
-import javax.inject.Named;
-import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.di.CommonsDaggerAppCompatActivity;
-import fr.free.nrw.commons.kvstore.JsonKvStore;
-import fr.free.nrw.commons.utils.SystemThemeUtils;
-import io.reactivex.disposables.CompositeDisposable;
-
-public abstract class BaseActivity extends CommonsDaggerAppCompatActivity {
-    @Inject
-    @Named("default_preferences")
-    public JsonKvStore defaultKvStore;
-
-    @Inject
-    SystemThemeUtils systemThemeUtils;
-
-    protected CompositeDisposable compositeDisposable = new CompositeDisposable();
-    protected boolean wasPreviouslyDarkTheme;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        wasPreviouslyDarkTheme = systemThemeUtils.isDeviceInNightMode();
-        setTheme(wasPreviouslyDarkTheme ? R.style.DarkAppTheme : R.style.LightAppTheme);
-        float fontScale = android.provider.Settings.System.getFloat(
-            getBaseContext().getContentResolver(),
-            android.provider.Settings.System.FONT_SCALE,
-            1f);
-        adjustFontScale(getResources().getConfiguration(), fontScale);
-    }
-
-    @Override
-    protected void onResume() {
-        // Restart activity if theme is changed
-        if (wasPreviouslyDarkTheme != systemThemeUtils.isDeviceInNightMode()) {
-            recreate();
-        }
-
-        super.onResume();
-    }
-
-    @Override
-    protected void onDestroy() {
-        super.onDestroy();
-        compositeDisposable.clear();
-    }
-
-    /**
-     * Apply fontScale on device
-     */
-    public void adjustFontScale(Configuration configuration, float scale) {
-        configuration.fontScale = scale;
-        final DisplayMetrics metrics = getResources().getDisplayMetrics();
-        final WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
-        wm.getDefaultDisplay().getMetrics(metrics);
-        metrics.scaledDensity = configuration.fontScale * metrics.density;
-        getBaseContext().getResources().updateConfiguration(configuration, metrics);
-    }
-
-}

app/src/main/java/fr/free/nrw/commons/theme/BaseActivity.kt

@@ -0,0 +1,65 @@
+package fr.free.nrw.commons.theme
+
+import android.content.res.Configuration
+import android.os.Bundle
+import android.util.DisplayMetrics
+import android.view.WindowManager
+import javax.inject.Inject
+import javax.inject.Named
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.di.CommonsDaggerAppCompatActivity
+import fr.free.nrw.commons.kvstore.JsonKvStore
+import fr.free.nrw.commons.utils.SystemThemeUtils
+import io.reactivex.disposables.CompositeDisposable
+
+
+abstract class BaseActivity : CommonsDaggerAppCompatActivity() {
+
+    @Inject
+    @field:Named("default_preferences")
+    lateinit var defaultKvStore: JsonKvStore
+
+    @Inject
+    lateinit var systemThemeUtils: SystemThemeUtils
+
+    protected val compositeDisposable = CompositeDisposable()
+    protected var wasPreviouslyDarkTheme: Boolean = false
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        wasPreviouslyDarkTheme = systemThemeUtils.isDeviceInNightMode()
+        setTheme(if (wasPreviouslyDarkTheme) R.style.DarkAppTheme else R.style.LightAppTheme)
+
+        val fontScale = android.provider.Settings.System.getFloat(
+            baseContext.contentResolver,
+            android.provider.Settings.System.FONT_SCALE,
+            1f
+        )
+        adjustFontScale(resources.configuration, fontScale)
+    }
+
+    override fun onResume() {
+        // Restart activity if theme is changed
+        if (wasPreviouslyDarkTheme != systemThemeUtils.isDeviceInNightMode()) {
+            recreate()
+        }
+        super.onResume()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        compositeDisposable.clear()
+    }
+
+    /**
+     * Apply fontScale on device
+     */
+    fun adjustFontScale(configuration: Configuration, scale: Float) {
+        configuration.fontScale = scale
+        val metrics = resources.displayMetrics
+        val wm = getSystemService(WINDOW_SERVICE) as WindowManager
+        wm.defaultDisplay.getMetrics(metrics)
+        metrics.scaledDensity = configuration.fontScale * metrics.density
+        baseContext.resources.updateConfiguration(configuration, metrics)
+    }
+}

app/src/main/java/fr/free/nrw/commons/ui/PasteSensitiveTextInputEditText.java

@@ -1,65 +0,0 @@
-package fr.free.nrw.commons.ui;
-
-import android.content.Context;
-import android.content.res.TypedArray;
-import android.os.Build.VERSION;
-import android.util.AttributeSet;
-import com.google.android.material.textfield.TextInputEditText;
-import fr.free.nrw.commons.R;
-
-public class PasteSensitiveTextInputEditText extends TextInputEditText {
-
-    private boolean formattingAllowed = true;
-
-    public PasteSensitiveTextInputEditText(final Context context) {
-        super(context);
-    }
-
-    public PasteSensitiveTextInputEditText(final Context context, final AttributeSet attrs) {
-        super(context, attrs);
-        formattingAllowed = extractFormattingAttribute(context, attrs);
-    }
-
-    @Override
-    public boolean onTextContextMenuItem(int id) {
-
-        // if not paste command, or formatting is allowed, return default
-        if(id != android.R.id.paste || formattingAllowed){
-            return super.onTextContextMenuItem(id);
-        }
-
-        // if its paste and formatting not allowed
-        boolean proceeded;
-        if(VERSION.SDK_INT >= 23) {
-            proceeded = super.onTextContextMenuItem(android.R.id.pasteAsPlainText);
-        }else {
-            proceeded = super.onTextContextMenuItem(id);
-            if (proceeded && getText() != null) {
-                // rewrite with plain text so formatting is lost
-                setText(getText().toString());
-                setSelection(getText().length());
-            }
-        }
-        return proceeded;
-    }
-
-    private boolean extractFormattingAttribute(Context context, AttributeSet attrs){
-
-        boolean formatAllowed = true;
-
-        TypedArray a = context.getTheme().obtainStyledAttributes(
-            attrs, R.styleable.PasteSensitiveTextInputEditText, 0, 0);
-
-        try {
-            formatAllowed = a.getBoolean(
-                R.styleable.PasteSensitiveTextInputEditText_allowFormatting, true);
-        } finally {
-            a.recycle();
-        }
-        return formatAllowed;
-    }
-
-    public void setFormattingAllowed(boolean formattingAllowed){
-        this.formattingAllowed = formattingAllowed;
-    }
-}

app/src/main/java/fr/free/nrw/commons/ui/PasteSensitiveTextInputEditText.kt

@@ -0,0 +1,60 @@
+package fr.free.nrw.commons.ui
+
+import android.content.Context
+import android.content.res.TypedArray
+import android.os.Build
+import android.os.Build.VERSION
+import android.util.AttributeSet
+import com.google.android.material.textfield.TextInputEditText
+import fr.free.nrw.commons.R
+
+
+class PasteSensitiveTextInputEditText @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null
+) : TextInputEditText(context, attrs) {
+
+    private var formattingAllowed: Boolean = true
+
+    init {
+        if (attrs != null) {
+            formattingAllowed = extractFormattingAttribute(context, attrs)
+        }
+    }
+
+    override fun onTextContextMenuItem(id: Int): Boolean {
+        // if not paste command, or formatting is allowed, return default
+        if (id != android.R.id.paste || formattingAllowed) {
+            return super.onTextContextMenuItem(id)
+        }
+
+        // if it's paste and formatting not allowed
+        val proceeded: Boolean = if (VERSION.SDK_INT >= 23) {
+            super.onTextContextMenuItem(android.R.id.pasteAsPlainText)
+        } else {
+            val success = super.onTextContextMenuItem(id)
+            if (success && text != null) {
+                // rewrite with plain text so formatting is lost
+                setText(text.toString())
+                setSelection(text?.length ?: 0)
+            }
+            success
+        }
+        return proceeded
+    }
+
+    private fun extractFormattingAttribute(context: Context, attrs: AttributeSet): Boolean {
+        val a = context.theme.obtainStyledAttributes(
+            attrs, R.styleable.PasteSensitiveTextInputEditText, 0, 0
+        )
+        return try {
+            a.getBoolean(R.styleable.PasteSensitiveTextInputEditText_allowFormatting, true)
+        } finally {
+            a.recycle()
+        }
+    }
+
+    fun setFormattingAllowed(formattingAllowed: Boolean) {
+        this.formattingAllowed = formattingAllowed
+    }
+}

app/src/main/java/fr/free/nrw/commons/ui/widget/HtmlTextView.java

@@ -1,36 +0,0 @@
-package fr.free.nrw.commons.ui.widget;
-
-import android.content.Context;
-import android.text.method.LinkMovementMethod;
-import android.util.AttributeSet;
-
-import androidx.appcompat.widget.AppCompatTextView;
-
-import fr.free.nrw.commons.utils.StringUtil;
-
-/**
- * An {@link AppCompatTextView} which formats the text to HTML displayable text and makes any
- * links clickable.
- */
-public class HtmlTextView extends AppCompatTextView {
-
-    /**
-     * Constructs a new instance of HtmlTextView
-     * @param context the context of the view
-     * @param attrs the set of attributes for the view
-     */
-    public HtmlTextView(Context context, AttributeSet attrs) {
-        super(context, attrs);
-
-        setMovementMethod(LinkMovementMethod.getInstance());
-        setText(StringUtil.fromHtml(getText().toString()));
-    }
-
-    /**
-     * Sets the text to be displayed
-     * @param newText the text to be displayed
-     */
-    public void setHtmlText(String newText) {
-        setText(StringUtil.fromHtml(newText));
-    }
-}

app/src/main/java/fr/free/nrw/commons/ui/widget/HtmlTextView.kt

@@ -0,0 +1,32 @@
+package fr.free.nrw.commons.ui.widget
+
+import android.content.Context
+import android.text.method.LinkMovementMethod
+import android.util.AttributeSet
+
+import androidx.appcompat.widget.AppCompatTextView
+
+import fr.free.nrw.commons.utils.StringUtil
+
+/**
+ * An [AppCompatTextView] which formats the text to HTML displayable text and makes any
+ * links clickable.
+ */
+class HtmlTextView @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null
+) : AppCompatTextView(context, attrs) {
+
+    init {
+        movementMethod = LinkMovementMethod.getInstance()
+        text = StringUtil.fromHtml(text.toString())
+    }
+
+    /**
+     * Sets the text to be displayed
+     * @param newText the text to be displayed
+     */
+    fun setHtmlText(newText: String) {
+        text = StringUtil.fromHtml(newText)
+    }
+}

app/src/main/java/fr/free/nrw/commons/ui/widget/OverlayDialog.java

@@ -1,70 +0,0 @@
-package fr.free.nrw.commons.ui.widget;
-
-import android.app.Dialog;
-import android.graphics.Color;
-import android.graphics.drawable.ColorDrawable;
-import android.os.Bundle;
-import android.view.Gravity;
-import android.view.View;
-import android.view.Window;
-import android.view.WindowManager;
-
-import androidx.annotation.NonNull;
-import androidx.fragment.app.DialogFragment;
-
-/**
- * a formatted dialog fragment
- * This class is used by NearbyInfoDialog
- */
-public abstract class OverlayDialog extends DialogFragment {
-
-    /**
-     * creates a DialogFragment with the correct style and theme
-     * @param savedInstanceState bundle re-constructed from a previous saved state
-     */
-    @Override
-    public void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setStyle(STYLE_NO_FRAME, android.R.style.Theme_Holo_Light);
-    }
-
-    /**
-     * When the view is created, sets the dialog layout to full screen
-     * 
-     * @param view the view being used
-     * @param savedInstanceState bundle re-constructed from a previous saved state
-     */
-    @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
-        setDialogLayoutToFullScreen();
-        super.onViewCreated(view, savedInstanceState);
-    }
-
-    /**
-     * sets the dialog layout to fullscreen
-     */
-    private void setDialogLayoutToFullScreen() {
-        Window window = getDialog().getWindow();
-        WindowManager.LayoutParams wlp = window.getAttributes();
-        window.requestFeature(Window.FEATURE_NO_TITLE);
-        wlp.gravity = Gravity.BOTTOM;
-        wlp.width = WindowManager.LayoutParams.MATCH_PARENT;
-        wlp.height = WindowManager.LayoutParams.MATCH_PARENT;
-        window.setAttributes(wlp);
-    }
-
-    /**
-     * builds custom dialog container
-     * 
-     * @param savedInstanceState the previously saved state
-     * @return the dialog
-     */
-    @NonNull
-    @Override
-    public Dialog onCreateDialog(Bundle savedInstanceState) {
-        Dialog dialog = super.onCreateDialog(savedInstanceState);
-        Window window = dialog.getWindow();
-        window.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
-        return dialog;
-    }
-}

app/src/main/java/fr/free/nrw/commons/ui/widget/OverlayDialog.kt

@@ -0,0 +1,64 @@
+package fr.free.nrw.commons.ui.widget
+
+import android.app.Dialog
+import android.graphics.Color
+import android.graphics.drawable.ColorDrawable
+import android.os.Bundle
+import android.view.Gravity
+import android.view.View
+import android.view.Window
+import android.view.WindowManager
+
+import androidx.fragment.app.DialogFragment
+
+/**
+ * A formatted dialog fragment
+ * This class is used by NearbyInfoDialog
+ */
+abstract class OverlayDialog : DialogFragment() {
+
+    /**
+     * Creates a DialogFragment with the correct style and theme
+     * @param savedInstanceState bundle re-constructed from a previous saved state
+     */
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setStyle(STYLE_NO_FRAME, android.R.style.Theme_Holo_Light)
+    }
+
+    /**
+     * When the view is created, sets the dialog layout to full screen
+     *
+     * @param view the view being used
+     * @param savedInstanceState bundle re-constructed from a previous saved state
+     */
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        setDialogLayoutToFullScreen()
+        super.onViewCreated(view, savedInstanceState)
+    }
+
+    /**
+     * Sets the dialog layout to fullscreen
+     */
+    private fun setDialogLayoutToFullScreen() {
+        val window = dialog?.window ?: return
+        val wlp = window.attributes
+        window.requestFeature(Window.FEATURE_NO_TITLE)
+        wlp.gravity = Gravity.BOTTOM
+        wlp.width = WindowManager.LayoutParams.MATCH_PARENT
+        wlp.height = WindowManager.LayoutParams.MATCH_PARENT
+        window.attributes = wlp
+    }
+
+    /**
+     * Builds custom dialog container
+     *
+     * @param savedInstanceState the previously saved state
+     * @return the dialog
+     */
+    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+        val dialog = super.onCreateDialog(savedInstanceState)
+        dialog.window?.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
+        return dialog
+    }
+}

app/src/main/java/fr/free/nrw/commons/upload/UploadActivity.java

@@ -1,8 +1,8 @@
 package fr.free.nrw.commons.upload;
 
 import static fr.free.nrw.commons.contributions.ContributionController.ACTION_INTERNAL_UPLOADS;
-import static fr.free.nrw.commons.utils.PermissionUtils.PERMISSIONS_STORAGE;
 import static fr.free.nrw.commons.utils.PermissionUtils.checkPermissionsAndPerformAction;
+import static fr.free.nrw.commons.utils.PermissionUtils.getPERMISSIONS_STORAGE;
 import static fr.free.nrw.commons.wikidata.WikidataConstants.PLACE_OBJECT;
 import static fr.free.nrw.commons.wikidata.WikidataConstants.SELECTED_NEARBY_PLACE;
 import static fr.free.nrw.commons.wikidata.WikidataConstants.SELECTED_NEARBY_PLACE_CATEGORY;
@@ -32,7 +32,6 @@ import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.viewpager.widget.PagerAdapter;
 import androidx.viewpager.widget.ViewPager;
 import androidx.work.ExistingWorkPolicy;
-import fr.free.nrw.commons.CommonsApplication;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.auth.LoginActivity;
 import fr.free.nrw.commons.auth.SessionManager;
@@ -277,7 +276,7 @@ public class UploadActivity extends BaseActivity implements UploadContract.View,
 
     public void checkStoragePermissions() {
         // Check if all required permissions are granted
-        final boolean hasAllPermissions = PermissionUtils.hasPermission(this, PERMISSIONS_STORAGE);
+        final boolean hasAllPermissions = PermissionUtils.hasPermission(this, getPERMISSIONS_STORAGE());
         final boolean hasPartialAccess = PermissionUtils.hasPartialAccess(this);
         if (hasAllPermissions || hasPartialAccess) {
             // All required permissions are granted, so enable UI elements and perform actions
@@ -297,7 +296,7 @@ public class UploadActivity extends BaseActivity implements UploadContract.View,
                         },
                     R.string.storage_permission_title,
                     R.string.write_storage_permission_rationale_for_image_share,
-                    PERMISSIONS_STORAGE);
+                    getPERMISSIONS_STORAGE());
             }
         }
         /* If all permissions are not granted and a dialog is already showing on screen

app/src/main/java/fr/free/nrw/commons/upload/UploadMediaDetailAdapter.java

@@ -22,7 +22,6 @@ import android.widget.ListView;
 import android.widget.TextView;
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.fragment.app.Fragment;
 import androidx.recyclerview.widget.RecyclerView;

app/src/main/java/fr/free/nrw/commons/upload/categories/CategoriesPresenter.kt

@@ -61,7 +61,7 @@ class CategoriesPresenter
                     .doOnNext {
                         view.showProgress(true)
                     }.switchMap(::searchResults)
-                    .map { repository.selectedCategories + it }
+                    .map { repository.getSelectedCategories() + it }
                     .map { it.distinctBy { categoryItem -> categoryItem.name } }
                     .observeOn(mainThreadScheduler)
                     .subscribe(
@@ -89,7 +89,7 @@ class CategoriesPresenter
         private fun searchResults(term: String): Observable<List<CategoryItem>>? {
             if (media == null) {
                 return repository
-                    .searchAll(term, getImageTitleList(), repository.selectedDepictions)
+                    .searchAll(term, getImageTitleList(), repository.getSelectedDepictions())
                     .subscribeOn(ioScheduler)
                     .map {
                         it.filter { categoryItem ->
@@ -101,13 +101,13 @@ class CategoriesPresenter
                 return Observable
                     .zip(
                         repository
-                            .getCategories(repository.selectedExistingCategories)
+                            .getCategories(repository.getSelectedExistingCategories())
                             .map { list ->
                                 list.map {
                                     CategoryItem(it.name, it.description, it.thumbnail, true)
                                 }
                             },
-                        repository.searchAll(term, getImageTitleList(), repository.selectedDepictions),
+                        repository.searchAll(term, getImageTitleList(), repository.getSelectedDepictions()),
                     ) { it1, it2 ->
                         it1 + it2
                     }.subscribeOn(ioScheduler)
@@ -138,7 +138,7 @@ class CategoriesPresenter
          * @return
          */
         private fun getImageTitleList(): List<String> =
-            repository.uploads
+            repository.getUploads()
                 .map { it.uploadMediaDetails[0].captionText }
                 .filterNot { TextUtils.isEmpty(it) }
 
@@ -146,7 +146,7 @@ class CategoriesPresenter
          * Verifies the number of categories selected, prompts the user if none selected
          */
         override fun verifyCategories() {
-            val selectedCategories = repository.selectedCategories
+            val selectedCategories = repository.getSelectedCategories()
             if (selectedCategories.isNotEmpty()) {
                 repository.setSelectedCategories(selectedCategories.map { it.name })
                 view.goToNextScreen()
@@ -173,14 +173,14 @@ class CategoriesPresenter
         ) {
             this.view = view
             this.media = media
-            repository.selectedExistingCategories = view.existingCategories
+            repository.setSelectedExistingCategories(view.existingCategories)
             compositeDisposable.add(
                 searchTerms
                     .observeOn(mainThreadScheduler)
                     .doOnNext {
                         view.showProgress(true)
                     }.switchMap(::searchResults)
-                    .map { repository.selectedCategories + it }
+                    .map { repository.getSelectedCategories() + it }
                     .map { it.distinctBy { categoryItem -> categoryItem.name } }
                     .observeOn(mainThreadScheduler)
                     .subscribe(
@@ -218,13 +218,21 @@ class CategoriesPresenter
             wikiText: String,
         ) {
             // check if view.existingCategories is null
-            if (repository.selectedCategories.isNotEmpty() ||
+            if (
-                (view.existingCategories != null && repository.selectedExistingCategories.size != view.existingCategories.size)
+                repository.getSelectedCategories().isNotEmpty()
+                        ||
+                (
+                view.existingCategories != null
+                        &&
+                repository.getSelectedExistingCategories().size
+                        !=
+                view.existingCategories.size
+                )
             ) {
                 val selectedCategories: MutableList<String> =
                     (
-                        repository.selectedCategories.map { it.name }.toMutableList() +
+                        repository.getSelectedCategories().map { it.name }.toMutableList() +
-                            repository.selectedExistingCategories
+                            repository.getSelectedExistingCategories()
                     ).toMutableList()
 
                 if (selectedCategories.isNotEmpty()) {
@@ -305,7 +313,7 @@ class CategoriesPresenter
 
         override fun selectCategories() {
             compositeDisposable.add(
-                repository.placeCategories
+                repository.getPlaceCategories()
                     .subscribeOn(ioScheduler)
                     .observeOn(mainThreadScheduler)
                     .subscribe(::selectNewCategories),

app/src/main/java/fr/free/nrw/commons/upload/depicts/DepictsPresenter.kt

@@ -93,14 +93,14 @@ class DepictsPresenter
                 return repository
                     .searchAllEntities(querystring)
                     .subscribeOn(ioScheduler)
-                    .map { repository.selectedDepictions + it + recentDepictedItemList + controller.loadFavoritesItems() }
+                    .map { repository.getSelectedDepictions() + it + recentDepictedItemList + controller.loadFavoritesItems() }
                     .map { it.filterNot { item -> WikidataDisambiguationItems.isDisambiguationItem(item.instanceOfs) } }
                     .map { it.distinctBy(DepictedItem::id) }
             } else {
                 return Flowable
                     .zip(
                         repository
-                            .getDepictions(repository.selectedExistingDepictions)
+                            .getDepictions(repository.getSelectedExistingDepictions())
                             .map { list ->
                                 list.map {
                                     DepictedItem(
@@ -118,7 +118,7 @@ class DepictsPresenter
                     ) { it1, it2 ->
                         it1 + it2
                     }.subscribeOn(ioScheduler)
-                    .map { repository.selectedDepictions + it + recentDepictedItemList + controller.loadFavoritesItems() }
+                    .map { repository.getSelectedDepictions() + it + recentDepictedItemList + controller.loadFavoritesItems() }
                     .map { it.filterNot { item -> WikidataDisambiguationItems.isDisambiguationItem(item.instanceOfs) } }
                     .map { it.distinctBy(DepictedItem::id) }
             }
@@ -135,7 +135,7 @@ class DepictsPresenter
          */
         override fun selectPlaceDepictions() {
             compositeDisposable.add(
-                repository.placeDepictions
+                repository.getPlaceDepictions()
                     .subscribeOn(ioScheduler)
                     .observeOn(mainThreadScheduler)
                     .subscribe(::selectNewDepictions),
@@ -188,10 +188,10 @@ class DepictsPresenter
          * from the depiction list
          */
         override fun verifyDepictions() {
-            if (repository.selectedDepictions.isNotEmpty()) {
+            if (repository.getSelectedDepictions().isNotEmpty()) {
                 if (::depictsDao.isInitialized) {
                     // save all the selected Depicted item in room Database
-                    depictsDao.savingDepictsInRoomDataBase(repository.selectedDepictions)
+                    depictsDao.savingDepictsInRoomDataBase(repository.getSelectedDepictions())
                 }
                 view.goToNextScreen()
             } else {
@@ -205,20 +205,20 @@ class DepictsPresenter
          */
         @SuppressLint("CheckResult")
         override fun updateDepictions(media: Media) {
-            if (repository.selectedDepictions.isNotEmpty() ||
+            if (repository.getSelectedDepictions().isNotEmpty() ||
-                repository.selectedExistingDepictions.size != view.existingDepictions.size
+                repository.getSelectedExistingDepictions().size != view.existingDepictions.size
             ) {
                 view.showProgressDialog()
                 val selectedDepictions: MutableList<String> =
                     (
-                        repository.selectedDepictions.map { it.id }.toMutableList() +
+                        repository.getSelectedDepictions().map { it.id }.toMutableList() +
-                            repository.selectedExistingDepictions
+                            repository.getSelectedExistingDepictions()
                     ).toMutableList()
 
                 if (selectedDepictions.isNotEmpty()) {
                     if (::depictsDao.isInitialized) {
                         // save all the selected Depicted item in room Database
-                        depictsDao.savingDepictsInRoomDataBase(repository.selectedDepictions)
+                        depictsDao.savingDepictsInRoomDataBase(repository.getSelectedDepictions())
                     }
 
                     compositeDisposable.add(
@@ -254,7 +254,7 @@ class DepictsPresenter
         ) {
             this.view = view
             this.media = media
-            repository.selectedExistingDepictions = view.existingDepictions
+            repository.setSelectedExistingDepictions(view.existingDepictions)
             compositeDisposable.add(
                 searchTerm
                     .observeOn(mainThreadScheduler)

app/src/main/java/fr/free/nrw/commons/upload/mediaDetails/UploadMediaDetailFragment.java

@@ -1,7 +1,6 @@
 package fr.free.nrw.commons.upload.mediaDetails;
 
 import static android.app.Activity.RESULT_OK;
-import static fr.free.nrw.commons.utils.ActivityUtils.startActivityWithFlags;
 
 import android.annotation.SuppressLint;
 import android.app.Activity;
@@ -45,6 +44,7 @@ import fr.free.nrw.commons.upload.UploadBaseFragment;
 import fr.free.nrw.commons.upload.UploadItem;
 import fr.free.nrw.commons.upload.UploadMediaDetail;
 import fr.free.nrw.commons.upload.UploadMediaDetailAdapter;
+import fr.free.nrw.commons.utils.ActivityUtils;
 import fr.free.nrw.commons.utils.DialogUtil;
 import fr.free.nrw.commons.utils.ImageUtils;
 import fr.free.nrw.commons.utils.NetworkUtils;
@@ -208,7 +208,7 @@ public class UploadMediaDetailFragment extends UploadBaseFragment implements
 
         try {
             if(!presenter.getImageQuality(indexOfFragment, inAppPictureLocation, getActivity())) {
-                startActivityWithFlags(
+                ActivityUtils.startActivityWithFlags(
                 getActivity(), MainActivity.class, Intent.FLAG_ACTIVITY_CLEAR_TOP,
                 Intent.FLAG_ACTIVITY_SINGLE_TOP);
             }

app/src/main/java/fr/free/nrw/commons/upload/structure/depictions/DepictModel.kt

@@ -39,7 +39,7 @@ class DepictModel
                     for (place in places) {
                         place.wikiDataEntityId?.let { qids.add(it) }
                     }
-                    repository.uploads.forEach { item ->
+                    repository.getUploads().forEach { item ->
                         if (item.gpsCoords != null && item.gpsCoords.imageCoordsExists) {
                             Coordinates2Country
                                 .countryQID(

app/src/main/java/fr/free/nrw/commons/upload/worker/UploadWorker.kt

@@ -47,6 +47,7 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import timber.log.Timber
 import java.util.Date
+import java.util.Random
 import java.util.regex.Pattern
 import javax.inject.Inject
 
@@ -548,33 +549,30 @@ class UploadWorker(
     }
 
     private fun findUniqueFileName(fileName: String): String {
-        var sequenceFileName: String?
+        var sequenceFileName: String? = fileName
-        var sequenceNumber = 1
+        val random = Random()
-        while (true) {
+
+        // Loops until sequenceFileName does not match any existing file names
+        while (mediaClient
+                .checkPageExistsUsingTitle(
+                    String.format(
+                        "File:%s",
+                        sequenceFileName,
+                    ),
+                ).blockingGet()) {
+
+            // Generate a random 5-character alphanumeric string
+            val randomHash = (random.nextInt(90000) + 10000).toString()
+
             sequenceFileName =
-                if (sequenceNumber == 1) {
+                if (fileName.indexOf('.') == -1) {
-                    fileName
+                    "$fileName #$randomHash"
                 } else {
-                    if (fileName.indexOf('.') == -1) {
+                    val regex =
-                        "$fileName $sequenceNumber"
+                        Pattern.compile("^(.*)(\\..+?)$")
-                    } else {
+                    val regexMatcher = regex.matcher(fileName)
-                        val regex =
+                    regexMatcher.replaceAll("$1 #$randomHash")
-                            Pattern.compile("^(.*)(\\..+?)$")
-                        val regexMatcher = regex.matcher(fileName)
-                        regexMatcher.replaceAll("$1 $sequenceNumber$2")
-                    }
                 }
-            if (!mediaClient
-                    .checkPageExistsUsingTitle(
-                        String.format(
-                            "File:%s",
-                            sequenceFileName,
-                        ),
-                    ).blockingGet()
-            ) {
-                break
-            }
-            sequenceNumber++
         }
         return sequenceFileName!!
     }

app/src/main/java/fr/free/nrw/commons/utils/AbstractTextWatcher.java

@@ -1,31 +0,0 @@
-package fr.free.nrw.commons.utils;
-
-import android.text.Editable;
-import android.text.TextWatcher;
-
-import androidx.annotation.NonNull;
-
-public class AbstractTextWatcher implements TextWatcher {
-    private final TextChange textChange;
-
-    public AbstractTextWatcher(@NonNull TextChange textChange) {
-        this.textChange = textChange;
-    }
-
-    @Override
-    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
-    }
-
-    @Override
-    public void onTextChanged(CharSequence s, int start, int before, int count) {
-        textChange.onTextChanged(s.toString());
-    }
-
-    @Override
-    public void afterTextChanged(Editable s) {
-    }
-
-    public interface TextChange {
-        void onTextChanged(String value);
-    }
-}

app/src/main/java/fr/free/nrw/commons/utils/AbstractTextWatcher.kt

@@ -0,0 +1,25 @@
+package fr.free.nrw.commons.utils
+
+import android.text.Editable
+import android.text.TextWatcher
+
+class AbstractTextWatcher(
+    private val textChange: TextChange
+) : TextWatcher {
+
+    override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
+        // No-op
+    }
+
+    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
+        textChange.onTextChanged(s.toString())
+    }
+
+    override fun afterTextChanged(s: Editable?) {
+        // No-op
+    }
+
+    interface TextChange {
+        fun onTextChanged(value: String)
+    }
+}

app/src/main/java/fr/free/nrw/commons/utils/ActivityUtils.java

@@ -1,15 +0,0 @@
-package fr.free.nrw.commons.utils;
-
-import android.content.Context;
-import android.content.Intent;
-
-public class ActivityUtils {
-
-    public static <T> void startActivityWithFlags(Context context, Class<T> cls, int... flags) {
-        Intent intent = new Intent(context, cls);
-        for (int flag : flags) {
-            intent.addFlags(flag);
-        }
-        context.startActivity(intent);
-    }
-}

app/src/main/java/fr/free/nrw/commons/utils/ActivityUtils.kt

@@ -0,0 +1,16 @@
+package fr.free.nrw.commons.utils
+
+import android.content.Context
+import android.content.Intent
+
+object ActivityUtils {
+
+    @JvmStatic
+    fun <T> startActivityWithFlags(context: Context, cls: Class<T>, vararg flags: Int) {
+        val intent = Intent(context, cls)
+        for (flag in flags) {
+            intent.addFlags(flag)
+        }
+        context.startActivity(intent)
+    }
+}

app/src/main/java/fr/free/nrw/commons/utils/CommonsDateUtil.java

@@ -1,44 +0,0 @@
-package fr.free.nrw.commons.utils;
-
-import java.text.SimpleDateFormat;
-import java.util.Locale;
-import java.util.TimeZone;
-
-/**
- * Provides util functions for formatting date time
- * Most of our formatting needs are addressed by the data library's DateUtil class
- * Methods should be added here only if DateUtil class doesn't provide for it already
- */
-public class CommonsDateUtil {
-
-    /**
-     * Gets SimpleDateFormat for short date pattern
-     * @return simpledateformat
-     */
-    public static SimpleDateFormat getIso8601DateFormatShort() {
-        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.ROOT);
-        simpleDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
-        return simpleDateFormat;
-    }
-
-    /**
-     * Gets SimpleDateFormat for date pattern returned by Media object
-     * @return simpledateformat
-     */
-    public static SimpleDateFormat getMediaSimpleDateFormat() {
-        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ROOT);
-        simpleDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
-        return simpleDateFormat;
-    }
-
-    /**
-     * Gets the timestamp pattern for a date
-     * @return timestamp
-     */
-        public static SimpleDateFormat getIso8601DateFormatTimestamp() {
-            final SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'",
-                Locale.ROOT);
-            simpleDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
-            return simpleDateFormat;
-    }
-}

app/src/main/java/fr/free/nrw/commons/utils/CommonsDateUtil.kt

@@ -0,0 +1,46 @@
+package fr.free.nrw.commons.utils
+
+import java.text.SimpleDateFormat
+import java.util.Locale
+import java.util.TimeZone
+
+/**
+ * Provides util functions for formatting date time.
+ * Most of our formatting needs are addressed by the data library's DateUtil class.
+ * Methods should be added here only if DateUtil class doesn't provide for it already.
+ */
+object CommonsDateUtil {
+
+    /**
+     * Gets SimpleDateFormat for short date pattern.
+     * @return simpleDateFormat
+     */
+    @JvmStatic
+    fun getIso8601DateFormatShort(): SimpleDateFormat {
+        val simpleDateFormat = SimpleDateFormat("yyyy-MM-dd", Locale.ROOT)
+        simpleDateFormat.timeZone = TimeZone.getTimeZone("UTC")
+        return simpleDateFormat
+    }
+
+    /**
+     * Gets SimpleDateFormat for date pattern returned by Media object.
+     * @return simpleDateFormat
+     */
+    @JvmStatic
+    fun getMediaSimpleDateFormat(): SimpleDateFormat {
+        val simpleDateFormat = SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ROOT)
+        simpleDateFormat.timeZone = TimeZone.getTimeZone("UTC")
+        return simpleDateFormat
+    }
+
+    /**
+     * Gets the timestamp pattern for a date.
+     * @return timestamp
+     */
+    @JvmStatic
+    fun getIso8601DateFormatTimestamp(): SimpleDateFormat {
+        val simpleDateFormat = SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ROOT)
+        simpleDateFormat.timeZone = TimeZone.getTimeZone("UTC")
+        return simpleDateFormat
+    }
+}

app/src/main/java/fr/free/nrw/commons/utils/DateUtil.java

@@ -1,53 +0,0 @@
-package fr.free.nrw.commons.utils;
-
-import static android.text.format.DateFormat.getBestDateTimePattern;
-
-import androidx.annotation.NonNull;
-
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.util.Date;
-import java.util.HashMap;
-import java.util.Locale;
-import java.util.Map;
-import java.util.TimeZone;
-
-public final class DateUtil {
-    private static Map<String, SimpleDateFormat> DATE_FORMATS = new HashMap<>();
-
-    // TODO: Switch to DateTimeFormatter when minSdk = 26.
-
-    public static synchronized String iso8601DateFormat(Date date) {
-        return getCachedDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ROOT, true).format(date);
-    }
-
-    public static synchronized Date iso8601DateParse(String date) throws ParseException {
-        return getCachedDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ROOT, true).parse(date);
-    }
-
-    public static String getMonthOnlyDateString(@NonNull Date date) {
-        return getDateStringWithSkeletonPattern(date, "MMMM d");
-    }
-
-    public static String getExtraShortDateString(@NonNull Date date) {
-        return getDateStringWithSkeletonPattern(date, "MMM d");
-    }
-
-    public static synchronized String getDateStringWithSkeletonPattern(@NonNull Date date, @NonNull String pattern) {
-        return getCachedDateFormat(getBestDateTimePattern(Locale.getDefault(), pattern), Locale.getDefault(), false).format(date);
-    }
-
-    private static SimpleDateFormat getCachedDateFormat(String pattern, Locale locale, boolean utc) {
-        if (!DATE_FORMATS.containsKey(pattern)) {
-            SimpleDateFormat df = new SimpleDateFormat(pattern, locale);
-            if (utc) {
-                df.setTimeZone(TimeZone.getTimeZone("UTC"));
-            }
-            DATE_FORMATS.put(pattern, df);
-        }
-        return DATE_FORMATS.get(pattern);
-    }
-
-    private DateUtil() {
-    }
-}

app/src/main/java/fr/free/nrw/commons/utils/DateUtil.kt

@@ -0,0 +1,62 @@
+package fr.free.nrw.commons.utils
+
+import android.text.format.DateFormat.getBestDateTimePattern
+import java.text.ParseException
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.HashMap
+import java.util.Locale
+import java.util.TimeZone
+
+/**
+ * Utility class for date formatting and parsing.
+ * TODO: Switch to DateTimeFormatter when minSdk = 26.
+ */
+object DateUtil {
+
+    private val DATE_FORMATS: MutableMap<String, SimpleDateFormat> = HashMap()
+
+    @JvmStatic
+    @Synchronized
+    fun iso8601DateFormat(date: Date): String {
+        return getCachedDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ROOT, true).format(date)
+    }
+
+    @JvmStatic
+    @Synchronized
+    @Throws(ParseException::class)
+    fun iso8601DateParse(date: String): Date {
+        return getCachedDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ROOT, true).parse(date)
+    }
+
+    @JvmStatic
+    fun getMonthOnlyDateString(date: Date): String {
+        return getDateStringWithSkeletonPattern(date, "MMMM d")
+    }
+
+    @JvmStatic
+    fun getExtraShortDateString(date: Date): String {
+        return getDateStringWithSkeletonPattern(date, "MMM d")
+    }
+
+    @JvmStatic
+    @Synchronized
+    fun getDateStringWithSkeletonPattern(date: Date, pattern: String): String {
+        return getCachedDateFormat(
+            getBestDateTimePattern(Locale.getDefault(), pattern),
+            Locale.getDefault(), false
+        ).format(date)
+    }
+
+    @JvmStatic
+    private fun getCachedDateFormat(pattern: String, locale: Locale, utc: Boolean): SimpleDateFormat {
+        if (!DATE_FORMATS.containsKey(pattern)) {
+            val df = SimpleDateFormat(pattern, locale)
+            if (utc) {
+                df.timeZone = TimeZone.getTimeZone("UTC")
+            }
+            DATE_FORMATS[pattern] = df
+        }
+        return DATE_FORMATS[pattern]!!
+    }
+}

app/src/main/java/fr/free/nrw/commons/utils/DeviceInfoUtil.java

@@ -1,91 +0,0 @@
-package fr.free.nrw.commons.utils;
-
-import android.content.Context;
-import android.os.Build;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import fr.free.nrw.commons.utils.model.ConnectionType;
-import fr.free.nrw.commons.utils.model.NetworkConnectionType;
-
-import static fr.free.nrw.commons.utils.model.ConnectionType.CELLULAR;
-import static fr.free.nrw.commons.utils.model.ConnectionType.CELLULAR_3G;
-import static fr.free.nrw.commons.utils.model.ConnectionType.CELLULAR_4G;
-import static fr.free.nrw.commons.utils.model.ConnectionType.NO_INTERNET;
-import static fr.free.nrw.commons.utils.model.ConnectionType.WIFI_NETWORK;
-import static fr.free.nrw.commons.utils.model.NetworkConnectionType.FOUR_G;
-import static fr.free.nrw.commons.utils.model.NetworkConnectionType.THREE_G;
-import static fr.free.nrw.commons.utils.model.NetworkConnectionType.TWO_G;
-import static fr.free.nrw.commons.utils.model.NetworkConnectionType.UNKNOWN;
-import static fr.free.nrw.commons.utils.model.NetworkConnectionType.WIFI;
-
-/**
- * Util class to get any information about the user's device
- * Ensure that any sensitive information like IMEI is not fetched/shared without user's consent
- */
-public class DeviceInfoUtil {
-    private static final Map<NetworkConnectionType, ConnectionType> TYPE_MAPPING = new HashMap<>();
-
-    static {
-        TYPE_MAPPING.put(TWO_G, CELLULAR);
-        TYPE_MAPPING.put(THREE_G, CELLULAR_3G);
-        TYPE_MAPPING.put(FOUR_G, CELLULAR_4G);
-        TYPE_MAPPING.put(WIFI, WIFI_NETWORK);
-        TYPE_MAPPING.put(UNKNOWN, CELLULAR);
-    }
-
-    /**
-     * Get network connection type
-     * @param context
-     * @return wifi/cellular-4g/cellular-3g/cellular-2g/no-internet
-     */
-    public static ConnectionType getConnectionType(Context context) {
-        if (!NetworkUtils.isInternetConnectionEstablished(context)) {
-            return NO_INTERNET;
-        }
-        NetworkConnectionType networkType = NetworkUtils.getNetworkType(context);
-        ConnectionType deviceNetworkType = TYPE_MAPPING.get(networkType);
-        return deviceNetworkType == null ? CELLULAR : deviceNetworkType;
-    }
-
-    /**
-     * Get Device manufacturer
-     * @return
-     */
-    public static String getDeviceManufacturer() {
-        return Build.MANUFACTURER;
-    }
-
-    /**
-     * Get Device model name
-     * @return
-     */
-    public static String getDeviceModel() {
-        return Build.MODEL;
-    }
-
-    /**
-     * Get Android version. Eg. 4.4.2
-     * @return
-     */
-    public static String getAndroidVersion() {
-        return Build.VERSION.RELEASE;
-    }
-
-    /**
-     * Get API Level. Eg. 26
-     * @return
-     */
-    public static String getAPILevel() {
-        return Build.VERSION.SDK;
-    }
-
-    /**
-     * Get Device.
-     * @return
-     */
-    public static String getDevice() {
-        return Build.DEVICE;
-    }
-}

app/src/main/java/fr/free/nrw/commons/utils/DeviceInfoUtil.kt

@@ -0,0 +1,80 @@
+package fr.free.nrw.commons.utils
+
+import android.content.Context
+import android.os.Build
+import fr.free.nrw.commons.utils.model.ConnectionType
+import fr.free.nrw.commons.utils.model.NetworkConnectionType
+
+/**
+ * Util class to get any information about the user's device
+ * Ensure that any sensitive information like IMEI is not fetched/shared without user's consent
+ */
+object DeviceInfoUtil {
+    private val TYPE_MAPPING = mapOf(
+        NetworkConnectionType.TWO_G to ConnectionType.CELLULAR,
+        NetworkConnectionType.THREE_G to ConnectionType.CELLULAR_3G,
+        NetworkConnectionType.FOUR_G to ConnectionType.CELLULAR_4G,
+        NetworkConnectionType.WIFI to ConnectionType.WIFI_NETWORK,
+        NetworkConnectionType.UNKNOWN to ConnectionType.CELLULAR
+    )
+
+    /**
+     * Get network connection type
+     * @param context
+     * @return wifi/cellular-4g/cellular-3g/cellular-2g/no-internet
+     */
+    @JvmStatic
+    fun getConnectionType(context: Context): ConnectionType {
+        return if (!NetworkUtils.isInternetConnectionEstablished(context)) {
+            ConnectionType.NO_INTERNET
+        } else {
+            val networkType = NetworkUtils.getNetworkType(context)
+            TYPE_MAPPING[networkType] ?: ConnectionType.CELLULAR
+        }
+    }
+
+    /**
+     * Get Device manufacturer
+     * @return
+     */
+    @JvmStatic
+    fun getDeviceManufacturer(): String {
+        return Build.MANUFACTURER
+    }
+
+    /**
+     * Get Device model name
+     * @return
+     */
+    @JvmStatic
+    fun getDeviceModel(): String {
+        return Build.MODEL
+    }
+
+    /**
+     * Get Android version. Eg. 4.4.2
+     * @return
+     */
+    @JvmStatic
+    fun getAndroidVersion(): String {
+        return Build.VERSION.RELEASE
+    }
+
+    /**
+     * Get API Level. Eg. 26
+     * @return
+     */
+    @JvmStatic
+    fun getAPILevel(): String {
+        return Build.VERSION.SDK
+    }
+
+    /**
+     * Get Device.
+     * @return
+     */
+    @JvmStatic
+    fun getDevice(): String {
+        return Build.DEVICE
+    }
+}