Fixes: #3091 Odd code in CategoryImagesListFragment

app/src/main/java/fr/free/nrw/commons/bookmarks/BookmarksActivity.java

@@ -17,14 +17,15 @@
 import butterknife.ButterKnife;
 import fr.free.nrw.commons.Media;
 import fr.free.nrw.commons.R;
+import fr.free.nrw.commons.category.CategoryImagesCallback;
 import fr.free.nrw.commons.contributions.ContributionController;
 import fr.free.nrw.commons.media.MediaDetailPagerFragment;
 import fr.free.nrw.commons.theme.NavigationBaseActivity;
 
 public class BookmarksActivity extends NavigationBaseActivity
         implements FragmentManager.OnBackStackChangedListener,
         MediaDetailPagerFragment.MediaDetailProvider,
-        AdapterView.OnItemClickListener {
+        AdapterView.OnItemClickListener, CategoryImagesCallback {
 
     private FragmentManager supportFragmentManager;
     private BookmarksPagerAdapter adapter;
@@ -102,12 +103,14 @@ public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
      * This method is called on success of API call for featured Images.
      * The viewpager will notified that number of items have changed.
      */
+    @Override
     public void viewPagerNotifyDataSetChanged() {
         if (mediaDetails!=null){
             mediaDetails.notifyDataSetChanged();
         }
     }
 
+
     /**
      * This method is called mediaDetailPagerFragment. It returns the Media Object at that Index
      * @param i It is the index of which media object is to be returned which is same as
@@ -136,4 +139,7 @@ public int getTotalMediaCount() {
         }
         return adapter.getMediaAdapter().getCount();
     }
+
+    @Override
+    public void requestMoreImages() { }
 }

app/src/main/java/fr/free/nrw/commons/bookmarks/pictures/BookmarkPicturesFragment.java

@@ -97,11 +97,7 @@ public void onResume() {
             gridView.setVisibility(GONE);
             if (gridAdapter != null) {
                 gridAdapter.clear();
-                try {
-                    ((BookmarksActivity) getContext()).viewPagerNotifyDataSetChanged();
-                }catch (Exception e){
-                    e.printStackTrace();
-                }
+                ((BookmarksActivity) getContext()).viewPagerNotifyDataSetChanged();
             }
             initList();
         }
@@ -203,11 +199,7 @@ private void handleSuccess(List<Media> collection) {
                 return;
             }
             gridAdapter.addItems(collection);
-            try {
-                ((BookmarksActivity) getContext()).viewPagerNotifyDataSetChanged();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
+            ((BookmarksActivity) getContext()).viewPagerNotifyDataSetChanged();
         }
         progressBar.setVisibility(GONE);
         statusTextView.setVisibility(GONE);

app/src/main/java/fr/free/nrw/commons/category/CategoryDetailsActivity.java

@@ -37,7 +37,7 @@
 
 public class CategoryDetailsActivity extends NavigationBaseActivity
         implements MediaDetailPagerFragment.MediaDetailProvider,
-                    AdapterView.OnItemClickListener{
+                    AdapterView.OnItemClickListener, CategoryImagesCallback {
 
 
     private FragmentManager supportFragmentManager;
@@ -219,6 +219,7 @@ public void onBackPressed() {
      * This method is called on success of API call for Images inside a category.
      * The viewpager will notified that number of items have changed.
      */
+    @Override
     public void viewPagerNotifyDataSetChanged() {
         if (mediaDetails!=null){
             mediaDetails.notifyDataSetChanged();
@@ -229,6 +230,7 @@ public void viewPagerNotifyDataSetChanged() {
      * This method is called when viewPager has reached its end.
      * Fetches more images using search query and adds it to the grid view and viewpager adapter
      */
+    @Override
     public void requestMoreImages() {
         if (categoryImagesListFragment!=null){
             categoryImagesListFragment.fetchMoreImagesViewPager();

app/src/main/java/fr/free/nrw/commons/category/CategoryImagesActivity.java

@@ -30,7 +30,7 @@ public class CategoryImagesActivity
         extends NavigationBaseActivity
         implements FragmentManager.OnBackStackChangedListener,
                     MediaDetailPagerFragment.MediaDetailProvider,
-                    AdapterView.OnItemClickListener{
+                    AdapterView.OnItemClickListener, CategoryImagesCallback {
 
 
     private FragmentManager supportFragmentManager;
@@ -149,6 +149,7 @@ public Media getMediaAtPosition(int i) {
      * This method is called on success of API call for featured Images.
      * The viewpager will notified that number of items have changed.
      */
+    @Override
     public void viewPagerNotifyDataSetChanged() {
         if (mediaDetails!=null){
             mediaDetails.notifyDataSetChanged();
@@ -199,6 +200,7 @@ public boolean onOptionsItemSelected(MenuItem item) {
      * This method is called when viewPager has reached its end.
      * Fetches more images using search query and adds it to the gridView and viewpager adapter
      */
+    @Override
     public void requestMoreImages() {
         if (categoryImagesListFragment!=null){
             categoryImagesListFragment.fetchMoreImagesViewPager();

app/src/main/java/fr/free/nrw/commons/category/CategoryImagesCallback.java

@@ -0,0 +1,13 @@
+package fr.free.nrw.commons.category;
+
+/**
+ * Callback for notifying the viewpager that the number of items have changed
+ * and for requesting more images when the viewpager has been scrolled to its end.
+ */
+
+public interface CategoryImagesCallback {
+   void viewPagerNotifyDataSetChanged();
+   void requestMoreImages();
+}
+
+

app/src/main/java/fr/free/nrw/commons/category/CategoryImagesListFragment.java

@@ -26,7 +26,6 @@
 import dagger.android.support.DaggerFragment;
 import fr.free.nrw.commons.Media;
 import fr.free.nrw.commons.R;
-import fr.free.nrw.commons.explore.categories.ExploreActivity;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
 import fr.free.nrw.commons.media.MediaClient;
 import fr.free.nrw.commons.utils.NetworkUtils;
@@ -251,22 +250,9 @@ private void handleSuccess(List<Media> collection) {
                 return;
             }
             gridAdapter.addItems(collection);
-            try {
-                ((CategoryImagesActivity) getContext()).viewPagerNotifyDataSetChanged();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
-            try {
-                ((CategoryDetailsActivity) getContext()).viewPagerNotifyDataSetChanged();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
-            try {
-                ((ExploreActivity) getContext()).viewPagerNotifyDataSetChanged();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
+            ((CategoryImagesCallback) getContext()).viewPagerNotifyDataSetChanged();
         }
+
         progressBar.setVisibility(GONE);
         isLoading = false;
         statusTextView.setVisibility(GONE);

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

@@ -24,6 +24,7 @@
 import butterknife.ButterKnife;
 import fr.free.nrw.commons.Media;
 import fr.free.nrw.commons.R;
+import fr.free.nrw.commons.category.CategoryImagesCallback;
 import fr.free.nrw.commons.explore.categories.SearchCategoryFragment;
 import fr.free.nrw.commons.explore.images.SearchImageFragment;
 import fr.free.nrw.commons.explore.recentsearches.RecentSearchesFragment;
@@ -37,7 +38,8 @@
  * Represents search screen of this app
  */
 
-public class SearchActivity extends NavigationBaseActivity implements MediaDetailPagerFragment.MediaDetailProvider{
+public class SearchActivity extends NavigationBaseActivity
+        implements MediaDetailPagerFragment.MediaDetailProvider, CategoryImagesCallback {
 
     @BindView(R.id.toolbar_search) Toolbar toolbar;
     @BindView(R.id.searchHistoryContainer) FrameLayout searchHistoryContainer;
@@ -150,6 +152,7 @@ public int getTotalMediaCount() {
      * This method is called on success of API call for image Search.
      * The viewpager will notified that number of items have changed.
      */
+    @Override
     public void viewPagerNotifyDataSetChanged() {
         if (mediaDetails!=null){
             mediaDetails.notifyDataSetChanged();
@@ -236,6 +239,7 @@ public void updateText(String query) {
      * This method is called when viewPager has reached its end.
      * Fetches more images using search query and adds it to the recycler view and viewpager adapter
      */
+    @Override
     public void requestMoreImages() {
         if (searchImageFragment!=null){
             searchImageFragment.addImagesToList(query);

app/src/main/java/fr/free/nrw/commons/explore/categories/ExploreActivity.java

@@ -23,6 +23,7 @@
 import butterknife.ButterKnife;
 import fr.free.nrw.commons.Media;
 import fr.free.nrw.commons.R;
+import fr.free.nrw.commons.category.CategoryImagesCallback;
 import fr.free.nrw.commons.category.CategoryImagesListFragment;
 import fr.free.nrw.commons.explore.SearchActivity;
 import fr.free.nrw.commons.explore.ViewPagerAdapter;
@@ -37,7 +38,7 @@
 public class ExploreActivity
         extends NavigationBaseActivity
         implements MediaDetailPagerFragment.MediaDetailProvider,
-        AdapterView.OnItemClickListener {
+        AdapterView.OnItemClickListener, CategoryImagesCallback {
 
     private static final String FEATURED_IMAGES_CATEGORY = "Category:Featured_pictures_on_Wikimedia_Commons";
     private static final String MOBILE_UPLOADS_CATEGORY = "Category:Uploaded_with_Mobile/Android";
@@ -145,6 +146,7 @@ public int getTotalMediaCount() {
      * This method is called on success of API call for featured images or mobile uploads.
      * The viewpager will notified that number of items have changed.
      */
+    @Override
     public void viewPagerNotifyDataSetChanged() {
         if (mediaDetails != null) {
             mediaDetails.notifyDataSetChanged();
@@ -172,6 +174,7 @@ public void onBackPressed() {
      * This method is called when viewPager has reached its end.
      * Fetches more images and adds them to the recycler view and viewpager adapter
      */
+    @Override
     public void requestMoreImages() {
         if (mobileImagesListFragment != null && tabLayout.getSelectedTabPosition() == 1) {
             mobileImagesListFragment.fetchMoreImagesViewPager();

app/src/main/java/fr/free/nrw/commons/explore/images/SearchImageFragment.java

@@ -198,7 +198,7 @@ private void handleSuccess(List<Media> mediaList) {
             progressBar.setVisibility(GONE);
             imagesAdapter.addAll(mediaList);
             imagesAdapter.notifyDataSetChanged();
-            ((SearchActivity)getContext()).viewPagerNotifyDataSetChanged();
+            ((SearchActivity) getContext()).viewPagerNotifyDataSetChanged();
         }
     }
 

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

@@ -29,16 +29,13 @@
 import butterknife.ButterKnife;
 import fr.free.nrw.commons.Media;
 import fr.free.nrw.commons.R;
+import fr.free.nrw.commons.category.CategoryImagesCallback;
 import fr.free.nrw.commons.auth.SessionManager;
 import fr.free.nrw.commons.bookmarks.Bookmark;
 import fr.free.nrw.commons.bookmarks.pictures.BookmarkPicturesContentProvider;
 import fr.free.nrw.commons.bookmarks.pictures.BookmarkPicturesDao;
-import fr.free.nrw.commons.category.CategoryDetailsActivity;
-import fr.free.nrw.commons.category.CategoryImagesActivity;
 import fr.free.nrw.commons.contributions.Contribution;
 import fr.free.nrw.commons.di.CommonsDaggerSupportFragment;
-import fr.free.nrw.commons.explore.SearchActivity;
-import fr.free.nrw.commons.explore.categories.ExploreActivity;
 import fr.free.nrw.commons.kvstore.JsonKvStore;
 import fr.free.nrw.commons.utils.ImageUtils;
 import fr.free.nrw.commons.utils.NetworkUtils;
@@ -332,28 +329,9 @@ public void onPageScrolled(int i, float v, int i2) {
             Timber.d("Returning as activity is destroyed!");
             return;
         }
-        if (i+1 >= adapter.getCount()){
-            try{
-                ((CategoryImagesActivity) getContext()).requestMoreImages();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
-            try{
-                ((CategoryDetailsActivity) getContext()).requestMoreImages();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
-            try{
-                ((SearchActivity) getContext()).requestMoreImages();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
-            try{
-                ((ExploreActivity) getContext()).requestMoreImages();
-            }catch (Exception e){
-                e.printStackTrace();
-            }
-        }
+        if (i+1 >= adapter.getCount())
+            ((CategoryImagesCallback) getContext()).requestMoreImages();
+
         getActivity().invalidateOptionsMenu();
     }