[GSoC] Saved Image Fragment Scroll State (#4528)

* Saved Image Fragment Scroll State

* Fix delete image

* Fixed Delete bug

* Changed custom selector icon

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

@@ -1,19 +1,7 @@
 package fr.free.nrw.commons.customselector.helper
 
-import android.content.Context
-import com.mapbox.android.core.FileUtils
 import fr.free.nrw.commons.customselector.model.Folder
 import fr.free.nrw.commons.customselector.model.Image
-import fr.free.nrw.commons.filepicker.Constants
-import timber.log.Timber
-import java.io.*
-import java.math.BigInteger
-import java.security.MessageDigest
-import java.security.NoSuchAlgorithmException
-import kotlin.collections.ArrayList
-import kotlin.collections.HashMap
-import kotlin.collections.LinkedHashMap
-
 
 /**
  * Image Helper object, includes all the static functions required by custom selector.
@@ -24,7 +12,7 @@ object ImageHelper {
     /**
      * Returns the list of folders from given image list.
      */
-    fun folderListFromImages(images: List<Image>): List<Folder> {
+    fun folderListFromImages(images: List<Image>): ArrayList<Folder> {
         val folderMap: MutableMap<Long, Folder> = LinkedHashMap()
         for (image in images) {
             val bucketId = image.bucketId
@@ -61,6 +49,17 @@ object ImageHelper {
         return list.indexOf(image)
     }
 
+    /**
+     * getIndex: Returns the index of image in given list.
+     */
+    fun getIndexFromId(list: ArrayList<Image>, imageId: Long): Int {
+        for(i in list){
+            if(i.id == imageId)
+                return list.indexOf(i)
+        }
+        return 0;
+    }
+
     /**
      * Gets the list of indices from the master list.
      */

app/src/main/java/fr/free/nrw/commons/customselector/listeners/FolderClickListener.kt

@@ -1,5 +1,5 @@
 package fr.free.nrw.commons.customselector.listeners
 
 interface FolderClickListener {
-    fun onFolderClick(folderId: Long, folderName: String)
+    fun onFolderClick(folderId: Long, folderName: String, lastItemId: Long)
 }

app/src/main/java/fr/free/nrw/commons/customselector/ui/adapter/FolderAdapter.kt

@@ -11,6 +11,7 @@ import com.bumptech.glide.Glide
 import fr.free.nrw.commons.R
 import fr.free.nrw.commons.customselector.listeners.FolderClickListener
 import fr.free.nrw.commons.customselector.model.Folder
+import fr.free.nrw.commons.customselector.model.Image
 
 class   FolderAdapter(
     /**
@@ -43,16 +44,38 @@ class   FolderAdapter(
      */
     override fun onBindViewHolder(holder: FolderViewHolder, position: Int) {
         val folder = folders[position]
+        val toBeRemoved = ArrayList<Image>()
+
+        for(image in folder.images) {
+            // Remove all the top images that do not exist anymore
+            if(context.contentResolver.getType(image.uri) == null){
+                // File not found
+                toBeRemoved.add(image)
+            } else {
+                break
+            }
+        }
+        holder.image.setImageDrawable (null)
+        folder.images.removeAll(toBeRemoved)
         val count = folder.images.size
+
+        if(count == 0) {
+            // Folder is empty, remove folder from the adapter.
+            holder.itemView.post{
+                val updatePosition = folders.indexOf(folder)
+                folders.removeAt(updatePosition)
+                notifyItemRemoved(updatePosition)
+                notifyItemRangeChanged(updatePosition, folders.size)
+            }
+        } else {
             val previewImage = folder.images[0]
             Glide.with(context).load(previewImage.uri).into(holder.image)
             holder.name.text = folder.name
             holder.count.text = count.toString()
             holder.itemView.setOnClickListener {
-            itemClickListener.onFolderClick(folder.bucketId, folder.name)
+                itemClickListener.onFolderClick(folder.bucketId, folder.name, 0)
+            }
         }
-
-        //todo load image thumbnail.
     }
 
     /**

app/src/main/java/fr/free/nrw/commons/customselector/ui/adapter/ImageAdapter.kt

@@ -1,9 +1,8 @@
 package fr.free.nrw.commons.customselector.ui.adapter
 
 import android.content.Context
-import android.view.ViewGroup
-import fr.free.nrw.commons.R
 import android.view.View
+import android.view.ViewGroup
 import android.widget.ImageView
 import android.widget.TextView
 import android.widget.Toast
@@ -11,6 +10,7 @@ import androidx.constraintlayout.widget.Group
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.RecyclerView
 import com.bumptech.glide.Glide
+import fr.free.nrw.commons.R
 import fr.free.nrw.commons.customselector.helper.ImageHelper
 import fr.free.nrw.commons.customselector.listeners.ImageSelectListener
 import fr.free.nrw.commons.customselector.model.Image
@@ -68,12 +68,21 @@ class ImageAdapter(
      */
     override fun onBindViewHolder(holder: ImageViewHolder, position: Int) {
         val image=images[position]
+        holder.image.setImageDrawable (null)
+        if (context.contentResolver.getType(image.uri) == null) {
+            // Image does not exist anymore, update adapter.
+            holder.itemView.post {
+                val updatedPosition = images.indexOf(image)
+                images.remove(image)
+                notifyItemRemoved(updatedPosition)
+                notifyItemRangeChanged(updatedPosition, images.size)
+            }
+        } else {
             val selectedIndex = ImageHelper.getIndex(selectedImages, image)
             val isSelected = selectedIndex != -1
             if (isSelected) {
                 holder.itemSelected(selectedIndex + 1)
-        }
+            } else {
-        else {
                 holder.itemUnselected();
             }
             Glide.with(context).load(image.uri).thumbnail(0.3f).into(holder.image)
@@ -82,6 +91,7 @@ class ImageAdapter(
                 selectOrRemoveImage(holder, position)
             }
         }
+    }
 
     /**
      * Handle click event on an image, update counter on images.
@@ -128,6 +138,10 @@ class ImageAdapter(
         return images.size
     }
 
+    fun getImageIdAt(position: Int): Long {
+        return images.get(position).id
+    }
+
     /**
      * Image view holder.
      */

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

@@ -7,7 +7,6 @@ import android.os.Bundle
 import android.view.View
 import android.widget.ImageButton
 import android.widget.TextView
-import androidx.fragment.app.FragmentManager
 import androidx.lifecycle.ViewModelProvider
 import fr.free.nrw.commons.R
 import fr.free.nrw.commons.customselector.listeners.FolderClickListener
@@ -17,7 +16,7 @@ import fr.free.nrw.commons.theme.BaseActivity
 import java.io.File
 import javax.inject.Inject
 
-class CustomSelectorActivity: BaseActivity(), FolderClickListener, ImageSelectListener, FragmentManager.OnBackStackChangedListener {
+class CustomSelectorActivity: BaseActivity(), FolderClickListener, ImageSelectListener {
 
     /**
      * View model.
@@ -58,10 +57,11 @@ class CustomSelectorActivity: BaseActivity(), FolderClickListener, ImageSelectLi
         setupViews()
 
         // Open folder if saved in prefs.
-        if(prefs.contains("FolderId")){
+        if(prefs.contains(FOLDER_ID)){
-            val lastOpenFolderId: Long = prefs.getLong("FolderId", 0L)
+            val lastOpenFolderId: Long = prefs.getLong(FOLDER_ID, 0L)
-            val lastOpenFolderName: String? = prefs.getString("FolderName", null)
+            val lastOpenFolderName: String? = prefs.getString(FOLDER_NAME, null)
-            lastOpenFolderName?.let { onFolderClick(lastOpenFolderId, it) }
+            val lastItemId: Long = prefs.getLong(ITEM_ID, 0)
+            lastOpenFolderName?.let { onFolderClick(lastOpenFolderId, it, lastItemId) }
         }
     }
 
@@ -107,9 +107,9 @@ class CustomSelectorActivity: BaseActivity(), FolderClickListener, ImageSelectLi
     /**
      * override on folder click, change the toolbar title on folder click.
      */
-    override fun onFolderClick(folderId: Long, folderName: String) {
+    override fun onFolderClick(folderId: Long, folderName: String, lastItemId: Long) {
         supportFragmentManager.beginTransaction()
-            .add(R.id.fragment_container, ImageFragment.newInstance(folderId))
+            .add(R.id.fragment_container, ImageFragment.newInstance(folderId, lastItemId))
             .addToBackStack(null)
             .commit()
 
@@ -172,25 +172,27 @@ class CustomSelectorActivity: BaseActivity(), FolderClickListener, ImageSelectLi
         super.onBackPressed()
         val fragment = supportFragmentManager.findFragmentById(R.id.fragment_container)
         if(fragment != null && fragment is FolderFragment){
+            isImageFragmentOpen = false
             changeTitle(getString(R.string.custom_selector_title))
         }
     }
 
+    /**
+     * On activity destroy
+     * If image fragment is open, overwrite its attributes otherwise discard the values.
+     */
     override fun onDestroy() {
         if(isImageFragmentOpen){
-            prefs.edit().putLong("FolderId", bucketId).putString("FolderName", bucketName).apply()
+            prefs.edit().putLong(FOLDER_ID, bucketId).putString(FOLDER_NAME, bucketName).apply()
         } else {
-            prefs.edit().remove("FolderId").remove("FolderName").apply()
+            prefs.edit().remove(FOLDER_ID).remove(FOLDER_NAME).apply()
         }
         super.onDestroy()
     }
 
-    /**
+    companion object {
-     * Called whenever the contents of the back stack change.
+        const val FOLDER_ID : String = "FolderId"
-     */
+        const val FOLDER_NAME : String = "FolderName"
-    override fun onBackStackChanged() {
+        const val ITEM_ID : String = "ItemId"
-        if(supportFragmentManager.backStackEntryCount == 0) {
-            isImageFragmentOpen = false
-        }
     }
 }

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

@@ -14,6 +14,7 @@ import fr.free.nrw.commons.customselector.helper.ImageHelper
 import fr.free.nrw.commons.customselector.model.Result
 import fr.free.nrw.commons.customselector.listeners.FolderClickListener
 import fr.free.nrw.commons.customselector.model.CallbackStatus
+import fr.free.nrw.commons.customselector.model.Folder
 import fr.free.nrw.commons.customselector.ui.adapter.FolderAdapter
 import fr.free.nrw.commons.di.CommonsDaggerSupportFragment
 import fr.free.nrw.commons.media.MediaClient
@@ -55,6 +56,11 @@ class FolderFragment : CommonsDaggerSupportFragment() {
      */
     private lateinit var gridLayoutManager: GridLayoutManager
 
+    /**
+     * Folder List.
+     */
+    private lateinit var folders : ArrayList<Folder>
+
     /**
      * Companion newInstance.
      */
@@ -102,7 +108,7 @@ class FolderFragment : CommonsDaggerSupportFragment() {
      */
     private fun handleResult(result: Result) {
         if(result.status is CallbackStatus.SUCCESS){
-            val folders = ImageHelper.folderListFromImages(result.images)
+            folders = ImageHelper.folderListFromImages(result.images)
             folderAdapter.init(folders)
             folderAdapter.notifyDataSetChanged()
             selectorRV?.let {
@@ -114,6 +120,11 @@ class FolderFragment : CommonsDaggerSupportFragment() {
         }
     }
 
+    override fun onResume() {
+        folderAdapter.notifyDataSetChanged()
+        super.onResume()
+    }
+
     /**
      * Return Column count ie span count for grid view adapter.
      */

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

@@ -1,6 +1,8 @@
 package fr.free.nrw.commons.customselector.ui.selector
 
+import android.net.Uri
 import android.os.Bundle
+import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -13,11 +15,15 @@ import fr.free.nrw.commons.R
 import fr.free.nrw.commons.customselector.helper.ImageHelper
 import fr.free.nrw.commons.customselector.listeners.ImageSelectListener
 import fr.free.nrw.commons.customselector.model.CallbackStatus
+import fr.free.nrw.commons.customselector.model.Image
 import fr.free.nrw.commons.customselector.model.Result
 import fr.free.nrw.commons.customselector.ui.adapter.ImageAdapter
 import fr.free.nrw.commons.di.CommonsDaggerSupportFragment
-import kotlinx.android.synthetic.main.fragment_custom_selector.*
+import fr.free.nrw.commons.theme.BaseActivity
 import kotlinx.android.synthetic.main.fragment_custom_selector.view.*
+import java.io.File
+import java.io.FileInputStream
+import java.net.URI
 import javax.inject.Inject
 
 class ImageFragment: CommonsDaggerSupportFragment() {
@@ -27,13 +33,18 @@ class ImageFragment: CommonsDaggerSupportFragment() {
      */
     private var bucketId: Long? = null
 
+    /**
+     * Last ImageItem Id.
+     */
+    private var lastItemId: Long? = null
+
     /**
      * View model for images.
      */
     private var  viewModel: CustomSelectorViewModel? = null
 
     /**
-     * View Elements
+     * View Elements.
      */
     private var selectorRV: RecyclerView? = null
     private var loader: ProgressBar? = null
@@ -67,14 +78,16 @@ class ImageFragment: CommonsDaggerSupportFragment() {
          * BucketId args name
          */
         const val BUCKET_ID = "BucketId"
+        const val LAST_ITEM_ID = "LastItemId"
 
         /**
          * newInstance from bucketId.
          */
-        fun newInstance(bucketId: Long): ImageFragment {
+        fun newInstance(bucketId: Long, lastItemId: Long): ImageFragment {
             val fragment = ImageFragment()
             val args = Bundle()
             args.putLong(BUCKET_ID, bucketId)
+            args.putLong(LAST_ITEM_ID, lastItemId)
             fragment.arguments = args
             return fragment
         }
@@ -87,6 +100,7 @@ class ImageFragment: CommonsDaggerSupportFragment() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         bucketId = arguments?.getLong(BUCKET_ID)
+        lastItemId = arguments?.getLong(LAST_ITEM_ID, 0)
         viewModel = ViewModelProvider(requireActivity(),customSelectorViewModelFactory).get(CustomSelectorViewModel::class.java)
     }
 
@@ -116,6 +130,8 @@ class ImageFragment: CommonsDaggerSupportFragment() {
         return root
     }
 
+    lateinit var filteredImages: ArrayList<Image>;
+
     /**
      * Handle view model result.
      */
@@ -123,9 +139,14 @@ class ImageFragment: CommonsDaggerSupportFragment() {
         if(result.status is CallbackStatus.SUCCESS){
             val images = result.images
             if(images.isNotEmpty()) {
-                imageAdapter.init(ImageHelper.filterImages(images,bucketId))
+                filteredImages = ImageHelper.filterImages(images, bucketId)
+                imageAdapter.init(filteredImages)
                 selectorRV?.let {
                     it.visibility = View.VISIBLE
+                    lastItemId?.let { pos ->
+                        (it.layoutManager as GridLayoutManager)
+                            .scrollToPosition(ImageHelper.getIndexFromId(filteredImages, pos))
+                    }
                 }
             }
             else{
@@ -149,11 +170,35 @@ class ImageFragment: CommonsDaggerSupportFragment() {
         // todo change span count depending on the device orientation and other factos.
     }
 
+    override fun onResume() {
+        imageAdapter.notifyDataSetChanged()
+        super.onResume()
+    }
+
     /**
-     * OnDestroy Cleanup the imageLoader coroutine.
+     * OnDestroy
+     * Cleanup the imageLoader coroutine.
+     * Save the Image Fragment state.
      */
     override fun onDestroy() {
         imageLoader?.cleanUP()
+
+        val position = (selectorRV?.layoutManager as GridLayoutManager)
+            .findFirstVisibleItemPosition()
+
+        // Check for empty RecyclerView.
+        if (position != -1) {
+            context?.let { context ->
+                context.getSharedPreferences(
+                    "CustomSelector",
+                    BaseActivity.MODE_PRIVATE
+                )?.let { prefs ->
+                    prefs.edit()?.let { editor ->
+                        editor.putLong("ItemId", imageAdapter.getImageIdAt(position))?.apply()
+                    }
+                }
+            }
+        }
         super.onDestroy()
     }
 }

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

@@ -13,6 +13,7 @@ import fr.free.nrw.commons.upload.FileProcessor
 import fr.free.nrw.commons.upload.FileUtilsWrapper
 import kotlinx.coroutines.*
 import timber.log.Timber
+import java.io.FileNotFoundException
 import java.io.IOException
 import java.net.UnknownHostException
 import java.util.*
@@ -86,6 +87,8 @@ class ImageLoader @Inject constructor(
             }
 
             val imageSHA1 = getImageSHA1(image.uri)
+            if(imageSHA1.isEmpty())
+                return@launch
             val uploadedStatus = getFromUploaded(imageSHA1)
 
             val sha1 = uploadedStatus?.let {
@@ -195,9 +198,14 @@ class ImageLoader @Inject constructor(
             mapImageSHA1[uri]?.let{
                 return@withContext it
             }
+            try {
                 val result = fileUtilsWrapper.getSHA1(context.contentResolver.openInputStream(uri))
                 mapImageSHA1[uri] = result
                 result
+            } catch (e: FileNotFoundException){
+                e.printStackTrace()
+                ""
+            }
         }
     }
 

app/src/main/res/layout/fragment_contributions_list.xml

@@ -79,7 +79,7 @@
             app:useCompatPadding="true"
             app:elevation="@dimen/tiny_margin"
             app:fabSize="mini"
-          app:srcCompat="@drawable/commons_logo"
+            app:srcCompat="@drawable/ic_custom_image_picker"
             android:background="@drawable/commons"/>
 
         <com.google.android.material.floatingactionbutton.FloatingActionButton

app/src/main/res/layout/item_custom_selector_folder.xml

@@ -16,7 +16,6 @@
 
     <androidx.constraintlayout.widget.ConstraintLayout
       android:layout_width="match_parent"
-      android:background="@color/white"
       android:layout_height="match_parent">
 
       <androidx.appcompat.widget.AppCompatImageView
@@ -29,7 +28,6 @@
         android:id="@+id/album_overlay"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:background="@color/black"
         android:alpha="0.15" />
 
       <LinearLayout