Improve Kotlin support for RecyclerView module (#2670)

* Improve Kotlin support for RecyclerView module with nullability annotations

Signed-off-by: Alex Saveau <[email protected]>

integration/recyclerview/src/main/java/com/bumptech/glide/integration/recyclerview/RecyclerToListViewScrollListener.java

@@ -1,5 +1,6 @@
 package com.bumptech.glide.integration.recyclerview;
 
+import android.support.annotation.NonNull;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.widget.AbsListView;
@@ -20,7 +21,7 @@ public final class RecyclerToListViewScrollListener extends RecyclerView.OnScrol
   private int lastVisibleCount = -1;
   private int lastItemCount = -1;
 
-  public RecyclerToListViewScrollListener(AbsListView.OnScrollListener scrollListener) {
+  public RecyclerToListViewScrollListener(@NonNull AbsListView.OnScrollListener scrollListener) {
     this.scrollListener = scrollListener;
   }
 

integration/recyclerview/src/main/java/com/bumptech/glide/integration/recyclerview/RecyclerViewPreloader.java

@@ -2,6 +2,7 @@
 
 import android.app.Activity;
 import android.app.Fragment;
+import android.support.annotation.NonNull;
 import android.support.v4.app.FragmentActivity;
 import android.support.v7.widget.RecyclerView;
 import com.bumptech.glide.Glide;
@@ -34,38 +35,42 @@ public final class RecyclerViewPreloader<T> extends RecyclerView.OnScrollListene
   /**
    * Helper constructor that accepts an {@link Activity}.
    */
-  public RecyclerViewPreloader(Activity activity,
-      PreloadModelProvider<T> preloadModelProvider,
-      PreloadSizeProvider<T> preloadDimensionProvider, int maxPreload) {
+  public RecyclerViewPreloader(@NonNull Activity activity,
+      @NonNull PreloadModelProvider<T> preloadModelProvider,
+      @NonNull PreloadSizeProvider<T> preloadDimensionProvider, int maxPreload) {
     this(Glide.with(activity), preloadModelProvider, preloadDimensionProvider, maxPreload);
   }
 
   /**
    * Helper constructor that accepts an {@link FragmentActivity}.
    */
-  public RecyclerViewPreloader(FragmentActivity fragmentActivity,
-      PreloadModelProvider<T> preloadModelProvider, PreloadSizeProvider<T> preloadDimensionProvider,
+  public RecyclerViewPreloader(@NonNull FragmentActivity fragmentActivity,
+      @NonNull PreloadModelProvider<T> preloadModelProvider,
+      @NonNull PreloadSizeProvider<T> preloadDimensionProvider,
       int maxPreload) {
     this(Glide.with(fragmentActivity), preloadModelProvider, preloadDimensionProvider, maxPreload);
   }
 
   /**
    * Helper constructor that accepts an {@link Fragment}.
    */
-  public RecyclerViewPreloader(Fragment fragment,
-      PreloadModelProvider<T> preloadModelProvider, PreloadSizeProvider<T> preloadDimensionProvider,
+  public RecyclerViewPreloader(@NonNull Fragment fragment,
+      @NonNull PreloadModelProvider<T> preloadModelProvider,
+      @NonNull PreloadSizeProvider<T> preloadDimensionProvider,
       int maxPreload) {
     this(Glide.with(fragment), preloadModelProvider, preloadDimensionProvider, maxPreload);
   }
 
   /**
    * Helper constructor that accepts an {@link android.support.v4.app.Fragment}.
    */
-  public RecyclerViewPreloader(android.support.v4.app.Fragment fragment,
-      PreloadModelProvider<T> preloadModelProvider, PreloadSizeProvider<T> preloadDimensionProvider,
+  public RecyclerViewPreloader(@NonNull android.support.v4.app.Fragment fragment,
+      @NonNull PreloadModelProvider<T> preloadModelProvider,
+      @NonNull PreloadSizeProvider<T> preloadDimensionProvider,
       int maxPreload) {
     this(Glide.with(fragment), preloadModelProvider, preloadDimensionProvider, maxPreload);
   }
+
   /**
    * Constructor that accepts interfaces for providing the dimensions of images to preload, the list
    * of models to preload for a given position, and the request to use to load images.
@@ -74,9 +79,9 @@ public RecyclerViewPreloader(android.support.v4.app.Fragment fragment,
    * @param preloadDimensionProvider Provides the dimensions of images to load.
    * @param maxPreload               Maximum number of items to preload.
    */
-  public RecyclerViewPreloader(RequestManager requestManager,
-      PreloadModelProvider<T> preloadModelProvider,
-      PreloadSizeProvider<T> preloadDimensionProvider, int maxPreload) {
+  public RecyclerViewPreloader(@NonNull RequestManager requestManager,
+      @NonNull PreloadModelProvider<T> preloadModelProvider,
+      @NonNull PreloadSizeProvider<T> preloadDimensionProvider, int maxPreload) {
 
     ListPreloader<T> listPreloader = new ListPreloader<>(requestManager, preloadModelProvider,
         preloadDimensionProvider, maxPreload);

library/src/main/java/com/bumptech/glide/Glide.java

@@ -602,7 +602,7 @@ private static RequestManagerRetriever getRetriever(@Nullable Context context) {
     // only occur due to errors with the Fragment lifecycle.
     Preconditions.checkNotNull(
         context,
-        "You cannot start a load on a not yet attached View or a  Fragment where getActivity() "
+        "You cannot start a load on a not yet attached View or a Fragment where getActivity() "
             + "returns null (which usually occurs when getActivity() is called before the Fragment "
             + "is attached or after the Fragment is destroyed).");
     return Glide.get(context).getRequestManagerRetriever();

library/src/main/java/com/bumptech/glide/ListPreloader.java

@@ -85,7 +85,7 @@ public interface PreloadModelProvider<U> {
      * @param item The model to load.
      */
     @Nullable
-    RequestBuilder<?> getPreloadRequestBuilder(U item);
+    RequestBuilder<?> getPreloadRequestBuilder(@NonNull U item);
   }
 
   /**
@@ -107,7 +107,7 @@ public interface PreloadSizeProvider<T> {
      * @param item A model
      */
     @Nullable
-    int[] getPreloadSize(T item, int adapterPosition, int perItemPosition);
+    int[] getPreloadSize(@NonNull T item, int adapterPosition, int perItemPosition);
   }
 
   /**
@@ -119,8 +119,9 @@ public interface PreloadSizeProvider<T> {
    * @param preloadDimensionProvider Provides the dimensions of images to load.
    * @param maxPreload               Maximum number of items to preload.
    */
-  public ListPreloader(RequestManager requestManager, PreloadModelProvider<T> preloadModelProvider,
-      PreloadSizeProvider<T> preloadDimensionProvider, int maxPreload) {
+  public ListPreloader(@NonNull RequestManager requestManager,
+      @NonNull PreloadModelProvider<T> preloadModelProvider,
+      @NonNull PreloadSizeProvider<T> preloadDimensionProvider, int maxPreload) {
     this.requestManager = requestManager;
     this.preloadModelProvider = preloadModelProvider;
     this.preloadDimensionProvider = preloadDimensionProvider;
@@ -169,12 +170,12 @@ private void preload(int from, int to) {
     if (from < to) {
       // Increasing
       for (int i = start; i < end; i++) {
-        preloadAdapterPosition(this.preloadModelProvider.getPreloadItems(i), i, true);
+        preloadAdapterPosition(preloadModelProvider.getPreloadItems(i), i, true);
       }
     } else {
       // Decreasing
       for (int i = end - 1; i >= start; i--) {
-        preloadAdapterPosition(this.preloadModelProvider.getPreloadItems(i), i, false);
+        preloadAdapterPosition(preloadModelProvider.getPreloadItems(i), i, false);
       }
     }
 

library/src/main/java/com/bumptech/glide/util/FixedPreloadSizeProvider.java

@@ -1,5 +1,7 @@
 package com.bumptech.glide.util;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import com.bumptech.glide.ListPreloader;
 
 /**
@@ -21,8 +23,9 @@ public FixedPreloadSizeProvider(int width, int height) {
     this.size = new int[] { width, height };
   }
 
+  @Nullable
   @Override
-  public int[] getPreloadSize(T item, int adapterPosition, int itemPosition) {
+  public int[] getPreloadSize(@NonNull T item, int adapterPosition, int itemPosition) {
     return size;
   }
 }

library/src/main/java/com/bumptech/glide/util/ViewPreloadSizeProvider.java

@@ -1,5 +1,7 @@
 package com.bumptech.glide.util;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import com.bumptech.glide.ListPreloader;
 import com.bumptech.glide.request.target.SizeReadyCallback;
@@ -43,8 +45,9 @@ public ViewPreloadSizeProvider(View view) {
     this.viewTarget = new SizeViewTarget(view, this);
   }
 
+  @Nullable
   @Override
-  public int[] getPreloadSize(T item, int adapterPosition, int itemPosition) {
+  public int[] getPreloadSize(@NonNull T item, int adapterPosition, int itemPosition) {
     if (size == null) {
       return null;
     } else {

library/src/test/java/com/bumptech/glide/ListPreloaderTest.java

@@ -9,6 +9,7 @@
 import static org.mockito.Mockito.verify;
 
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import com.bumptech.glide.request.target.SizeReadyCallback;
 import com.bumptech.glide.request.target.Target;
 import java.util.ArrayList;
@@ -36,7 +37,7 @@ public class ListPreloaderTest {
   @Mock private RequestManager requestManager;
 
   @Before
-  public void setUp() throws Exception {
+  public void setUp() {
     MockitoAnnotations.initMocks(this);
   }
 
@@ -73,7 +74,7 @@ public void testGetItemsIsCalledInOrderIncreasing() {
       private int expectedPosition;
 
       @Override
-      public int[] getPreloadSize(Object item, int adapterPosition, int itemPosition) {
+      public int[] getPreloadSize(@NonNull Object item, int adapterPosition, int itemPosition) {
         return new int[] { 10, 10 };
       }
 
@@ -83,10 +84,10 @@ public List<Object> getPreloadItems(int position) {
         return objects.subList(position - 11, position + 1 - 11);
       }
 
-      @NonNull
+      @Nullable
       @Override
       @SuppressWarnings("unchecked")
-      public RequestBuilder<Object> getPreloadRequestBuilder(Object item) {
+      public RequestBuilder<Object> getPreloadRequestBuilder(@NonNull Object item) {
         assertEquals(objects.get(expectedPosition), item);
         expectedPosition++;
         return mock(RequestBuilder.class);
@@ -134,7 +135,7 @@ public void testGetItemsIsCalledInOrderDecreasing() {
       private int expectedPosition = toPreload - 1;
 
       @Override
-      public int[] getPreloadSize(Object item, int adapterPosition, int itemPosition) {
+      public int[] getPreloadSize(@NonNull Object item, int adapterPosition, int itemPosition) {
         return new int[] { 10, 10 };
       }
 
@@ -147,10 +148,10 @@ public List<Object> getPreloadItems(int position) {
         return objects.subList(position, position + 1);
       }
 
-      @NonNull
+      @Nullable
       @Override
       @SuppressWarnings("unchecked")
-      public RequestBuilder<Object> getPreloadRequestBuilder(Object item) {
+      public RequestBuilder<Object> getPreloadRequestBuilder(@NonNull Object item) {
         assertEquals(objects.get(expectedPosition), item);
         expectedPosition--;
         return mock(RequestBuilder.class);
@@ -253,7 +254,7 @@ public List<Object> getPreloadItems(int position) {
   }
 
   @Test
-  public void testMultipleItemsForPositionIncreasing() throws NoSuchFieldException {
+  public void testMultipleItemsForPositionIncreasing() {
     final List<Object> objects = new ArrayList<>();
     objects.add(new Object());
     objects.add(new Object());
@@ -267,16 +268,16 @@ public List<Object> getPreloadItems(int position) {
       }
 
       @Override
-      public int[] getPreloadSize(Object item, int adapterPosition, int itemPosition) {
+      public int[] getPreloadSize(@NonNull Object item, int adapterPosition, int itemPosition) {
         assertEquals(expectedPosition / 2, adapterPosition);
         assertEquals(expectedPosition % 2, itemPosition);
         expectedPosition++;
         return itemPosition == 0 ? new int[] { 10, 11 } : new int[] { 20, 21 };
       }
 
-      @NonNull
+      @Nullable
       @Override
-      public RequestBuilder<Object> getPreloadRequestBuilder(Object item) {
+      public RequestBuilder<Object> getPreloadRequestBuilder(@NonNull Object item) {
         return request;
       }
     };
@@ -291,7 +292,7 @@ public RequestBuilder<Object> getPreloadRequestBuilder(Object item) {
   }
 
   @Test
-  public void testMultipleItemsForPositionDecreasing() throws NoSuchFieldException {
+  public void testMultipleItemsForPositionDecreasing() {
     final List<Object> objects = new ArrayList<>();
     objects.add(new Object());
     objects.add(new Object());
@@ -305,16 +306,16 @@ public List<Object> getPreloadItems(int position) {
       }
 
       @Override
-      public int[] getPreloadSize(Object item, int adapterPosition, int itemPosition) {
+      public int[] getPreloadSize(@NonNull Object item, int adapterPosition, int itemPosition) {
         assertEquals(expectedPosition / 2, adapterPosition);
         assertEquals(expectedPosition % 2, itemPosition);
         expectedPosition--;
         return itemPosition == 0 ? new int[] { 10, 11 } : new int[] { 20, 21 };
       }
 
-      @NonNull
+      @Nullable
       @Override
-      public RequestBuilder<Object> getPreloadRequestBuilder(Object item) {
+      public RequestBuilder<Object> getPreloadRequestBuilder(@NonNull Object item) {
         return request;
       }
     };
@@ -358,9 +359,9 @@ public List<Object> getPreloadItems(int position) {
         return objects.subList(position - 11, position - 10);
       }
 
-      @NonNull
+      @Nullable
       @Override
-      public RequestBuilder<Object> getPreloadRequestBuilder(Object item) {
+      public RequestBuilder<Object> getPreloadRequestBuilder(@NonNull Object item) {
         loadedObjects.add(item);
         return super.getPreloadRequestBuilder(item);
       }
@@ -386,15 +387,16 @@ public List<Object> getPreloadItems(int position) {
       return result;
     }
 
-    @NonNull
+    @Nullable
     @Override
     @SuppressWarnings("unchecked")
-    public RequestBuilder<Object> getPreloadRequestBuilder(Object item) {
+    public RequestBuilder<Object> getPreloadRequestBuilder(@NonNull Object item) {
       return mock(RequestBuilder.class);
     }
 
+    @Nullable
     @Override
-    public int[] getPreloadSize(Object item, int adapterPosition, int itemPosition) {
+    public int[] getPreloadSize(@NonNull Object item, int adapterPosition, int itemPosition) {
       return new int[] { 100, 100 };
     }
   }

samples/flickr/src/main/java/com/bumptech/glide/samples/flickr/FlickrPhotoGrid.java

@@ -5,6 +5,7 @@
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.support.v7.widget.GridLayoutManager;
 import android.support.v7.widget.RecyclerView;
@@ -78,7 +79,7 @@ public View onCreateView(
 
     final int gridMargin = getResources().getDimensionPixelOffset(R.dimen.grid_margin);
     int spanCount = getResources().getDisplayMetrics().widthPixels / (photoSize + (2 * gridMargin));
-    grid = (RecyclerView) result.findViewById(R.id.flickr_photo_grid);
+    grid = result.findViewById(R.id.flickr_photo_grid);
     layoutManager = new GridLayoutManager(getActivity(), spanCount);
     grid.setLayoutManager(layoutManager);
 
@@ -199,9 +200,9 @@ public List<Photo> getPreloadItems(int position) {
       return photos.subList(position, position + 1);
     }
 
-    @NonNull
+    @Nullable
     @Override
-    public RequestBuilder<Drawable> getPreloadRequestBuilder(Photo item) {
+    public RequestBuilder<Drawable> getPreloadRequestBuilder(@NonNull Photo item) {
       return preloadRequest.load(item);
     }
   }