Fixed - #4844 : In peer review, deletion proposal is sent even if no reason is chosen (#4862)

* Fixed - #4844 : [Bug]: In peer review, deletion proposal is sent even if no reason is chosen

* Minor Changes

* Minor Fixes

* added required changes

* added required changes - 1

* Added Test For OK Button

* Minor Fixes

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

@@ -5,6 +5,7 @@ import static fr.free.nrw.commons.notification.NotificationHelper.NOTIFICATION_D
 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;
 import androidx.appcompat.app.AlertDialog;
@@ -39,6 +40,8 @@ public class DeleteHelper {
     private final PageEditClient pageEditClient;
     private final ViewUtilWrapper viewUtil;
     private final String username;
+    private AlertDialog d;
+    private DialogInterface.OnMultiChoiceClickListener listener;
 
     @Inject
     public DeleteHelper(NotificationHelper notificationHelper,
@@ -176,12 +179,17 @@ public class DeleteHelper {
             reasonListEnglish[2] = getLocalizedResources(context, Locale.ENGLISH).getString(R.string.delete_helper_ask_reason_copyright_logo);
         }
 
-        alert.setMultiChoiceItems(reasonList, checkedItems, (dialogInterface, position, isChecked) -> {
+        alert.setMultiChoiceItems(reasonList, checkedItems, listener = (dialogInterface, position, isChecked) -> {
+
             if (isChecked) {
                 mUserReason.add(position);
             } else {
                 mUserReason.remove((Integer.valueOf(position)));
             }
+
+            // disable the OK button if no reason selected
+            ((AlertDialog) dialogInterface).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(
+                !mUserReason.isEmpty());
         });
 
         alert.setPositiveButton(context.getString(R.string.ok), (dialogInterface, i) -> {
@@ -200,20 +208,39 @@ public class DeleteHelper {
             String finalReason = reason;
 
             Single.defer((Callable<SingleSource<Boolean>>) () ->
-                    makeDeletion(context, media, finalReason))
+                makeDeletion(context, media, finalReason))
-                    .subscribeOn(Schedulers.io())
+                .subscribeOn(Schedulers.io())
-                    .observeOn(AndroidSchedulers.mainThread())
+                .observeOn(AndroidSchedulers.mainThread())
-                    .subscribe(aBoolean -> {
+                .subscribe(aBoolean -> {
-                        if (aBoolean) {
+                    if (aBoolean) {
-                            reviewCallback.onSuccess();
+                        reviewCallback.onSuccess();
-                        } else {
+                    } else {
-                            reviewCallback.onFailure();
+                        reviewCallback.onFailure();
-                        }
+                    }
-                    });
+                });
 
         });
         alert.setNegativeButton(context.getString(R.string.cancel), (dialog, which) -> reviewCallback.onFailure());
-        AlertDialog d = alert.create();
+        d = alert.create();
         d.show();
+
+        // disable the OK button by default
+        d.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
+    }
+
+    /**
+     * returns the instance of shown AlertDialog,
+     * used for taking reference during unit test
+     * */
+    public AlertDialog getDialog(){
+        return  d;
+    }
+
+    /**
+     * returns the instance of shown DialogInterface.OnMultiChoiceClickListener,
+     * used for taking reference during unit test
+     * */
+    public DialogInterface.OnMultiChoiceClickListener getListener(){
+        return listener;
     }
 }

app/src/test/kotlin/fr/free/nrw/commons/delete/DeleteHelperTest.kt

@@ -1,5 +1,6 @@
 package fr.free.nrw.commons.delete
 
+import android.app.AlertDialog
 import android.content.Context
 import com.nhaarman.mockitokotlin2.eq
 import com.nhaarman.mockitokotlin2.mock
@@ -15,6 +16,7 @@ import io.reactivex.Observable
 import io.reactivex.Single
 import org.junit.Assert.assertNotNull
 import org.junit.Assert.assertTrue
+import org.junit.Assert.assertEquals
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -142,6 +144,21 @@ class DeleteHelperTest {
         deleteHelper.askReasonAndExecute(media, mContext, "My Question", ReviewController.DeleteReason.COPYRIGHT_VIOLATION, callback);
     }
 
+    @Test
+    fun alertDialogPositiveButtonDisableTest() {
+        val mContext = RuntimeEnvironment.getApplication().applicationContext
+        deleteHelper.askReasonAndExecute(media, mContext, "My Question", ReviewController.DeleteReason.COPYRIGHT_VIOLATION, callback);
+        assertEquals(false, deleteHelper.dialog.getButton(AlertDialog.BUTTON_POSITIVE).isEnabled)
+    }
+
+        @Test
+    fun alertDialogPositiveButtonEnableTest() {
+        val mContext = RuntimeEnvironment.getApplication().applicationContext
+        deleteHelper.askReasonAndExecute(media, mContext, "My Question", ReviewController.DeleteReason.COPYRIGHT_VIOLATION, callback);
+        deleteHelper.listener.onClick(deleteHelper.dialog,1,true);
+        assertEquals(true, deleteHelper.dialog.getButton(AlertDialog.BUTTON_POSITIVE).isEnabled)
+    }
+
     @Test(expected = RuntimeException::class)
     fun makeDeletionForEmptyCreatorName() {
         whenever(pageEditClient.prependEdit(ArgumentMatchers.anyString(), ArgumentMatchers.anyString(), ArgumentMatchers.anyString()))