Disabled review buttons while an image is being loaded (#3185)

* Disabled review buttons while an image is being loaded

* Added javadocs for the new methods

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

@@ -132,7 +132,10 @@ public class ReviewActivity extends AuthenticatedActivity {
             runRandomizer(); //Run randomizer whenever everything is ready so that a first random image will be added
         }
 
-        btnSkipImage.setOnClickListener(view -> runRandomizer());
+        btnSkipImage.setOnClickListener(view -> {
+            reviewPagerAdapter.disableButtons();
+            runRandomizer();
+        });
 
         btnSkipImage.setOnTouchListener((view, event) -> {
             if (event.getAction() == MotionEvent.ACTION_UP && event.getRawX() >= (
@@ -154,6 +157,7 @@ public class ReviewActivity extends AuthenticatedActivity {
                 .observeOn(AndroidSchedulers.mainThread())
                 .subscribe(media -> {
                     if (media != null) {
+                        reviewPagerAdapter.disableButtons();
                         updateImage(media);
                     }
                 }));
@@ -181,6 +185,7 @@ public class ReviewActivity extends AuthenticatedActivity {
                     String caption = String.format(getString(R.string.review_is_uploaded_by), fileName, revision.getUser());
                     imageCaption.setText(caption);
                     progressBar.setVisibility(View.GONE);
+                    reviewPagerAdapter.enableButtons();
                 }));
         reviewPager.setCurrentItem(0);
     }

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

@@ -81,6 +81,7 @@ public class ReviewImageFragment extends CommonsDaggerSupportFragment {
                         .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.review_copyright_yes_button_text);
@@ -90,6 +91,7 @@ public class ReviewImageFragment extends CommonsDaggerSupportFragment {
                         .reportPossibleCopyRightViolation(requireActivity(), getReviewCallback()));
                 break;
             case CATEGORY:
+                enableButtons();
                 question = getString(R.string.review_category);
                 explanation = updateCategoriesQuestion();
                 yesButtonText = getString(R.string.review_category_yes_button_text);
@@ -102,6 +104,7 @@ public class ReviewImageFragment extends CommonsDaggerSupportFragment {
                 });
                 break;
             case THANKS:
+                enableButtons();
                 question = getString(R.string.review_thanks);
                 explanation = getString(R.string.review_thanks_explanation, getReviewActivity().reviewController.firstRevision.getUser());
                 yesButtonText = getString(R.string.review_thanks_yes_button_text);
@@ -114,6 +117,7 @@ public class ReviewImageFragment extends CommonsDaggerSupportFragment {
                 });
                 break;
             default:
+                enableButtons();
                 question = "How did we get here?";
                 explanation = "No idea.";
                 yesButtonText = "yes";
@@ -142,6 +146,28 @@ public class ReviewImageFragment extends CommonsDaggerSupportFragment {
         };
     }
 
+    /**
+     * This function is called when an image has
+     * been loaded to enable the review buttons.
+     */
+    public void enableButtons() {
+        yesButton.setEnabled(true);
+        yesButton.setAlpha(1);
+        noButton.setEnabled(true);
+        noButton.setAlpha(1);
+    }
+
+    /**
+     * This function is called when an image is being loaded
+     * to disable the review buttons
+     */
+    public void disableButtons() {
+        yesButton.setEnabled(false);
+        yesButton.setAlpha(0.5f);
+        noButton.setEnabled(false);
+        noButton.setAlpha(0.5f);
+    }
+
     @OnClick(R.id.button_no)
     void onNoButtonClicked() {
         getReviewActivity().swipeToNext();

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

@@ -34,6 +34,26 @@ public class ReviewPagerAdapter extends FragmentStatePagerAdapter {
         }
     }
 
+    /**
+     * This function is called when an image has
+     * been loaded to enable the review buttons.
+     */
+    public void enableButtons() {
+        if (reviewImageFragments != null){
+            reviewImageFragments[0].enableButtons();
+        }
+    }
+
+    /**
+     * This function is called when an image is being loaded
+     * to disable the review buttons
+     */
+    public void disableButtons() {
+        if (reviewImageFragments != null){
+            reviewImageFragments[0].disableButtons();
+        }
+    }
+
     @Override
     public Fragment getItem(int position) {
         Bundle bundle = new Bundle();

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

@@ -58,6 +58,8 @@
       android:layout_margin="@dimen/activity_margin_horizontal"
       android:background="@android:color/transparent"
       android:text="@string/yes"
+      android:enabled="false"
+      android:alpha="0.5"
       android:textAllCaps="true"
       android:textAlignment="center"
       android:textColor="@color/yes_button_color"/>
@@ -68,6 +70,8 @@
       android:layout_width="0dp"
       android:layout_height="48dp"
       android:layout_weight="1"
+      android:enabled="false"
+      android:alpha="0.5"
       android:layout_margin="@dimen/activity_margin_horizontal"
       android:background="@android:color/transparent"
       android:text="@string/no"