Fix SimpleRecyclerViewAdapter ModelList event propagation.

This CL addresses the SimpleRecyclerViewAdapter propagating incomplete
events to the parent RecyclerViewAdapter, resulting in partial UI
updates.

The CL also adds a few tests that confirm the behavior of the SRVA.

Change-Id: I4c35b54e925853e91d686fde5cc476f3d2efe6f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2146063
Commit-Queue: Ender <ender@google.com>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758528}

ui/android/BUILD.gn

@@ -399,6 +399,7 @@ junit_binary("ui_junit_tests") {
     "junit/src/org/chromium/ui/modelutil/PropertyListModelTest.java",
     "junit/src/org/chromium/ui/modelutil/PropertyModelTest.java",
     "junit/src/org/chromium/ui/modelutil/SimpleListObservableTest.java",
+    "junit/src/org/chromium/ui/modelutil/SimpleRecyclerViewAdapterTest.java",
     "junit/src/org/chromium/ui/resources/dynamics/BitmapDynamicResourceTest.java",
     "junit/src/org/chromium/ui/resources/dynamics/ViewResourceAdapterTest.java",
     "junit/src/org/chromium/ui/shadows/ShadowAnimatedStateListDrawable.java",

ui/android/java/src/org/chromium/ui/modelutil/SimpleRecyclerViewAdapter.java

@@ -73,7 +73,7 @@ public class SimpleRecyclerViewAdapter
         mListObserver = new ListObserver<Void>() {
             @Override
             public void onItemRangeInserted(ListObservable source, int index, int count) {
-                notifyItemInserted(index);
+                notifyItemRangeInserted(index, count);
             }
 
             @Override
@@ -84,7 +84,7 @@ public class SimpleRecyclerViewAdapter
             @Override
             public void onItemRangeChanged(
                     ListObservable<Void> source, int index, int count, @Nullable Void payload) {
-                notifyItemChanged(index);
+                notifyItemRangeChanged(index, count);
             }
 
             @Override

ui/android/junit/src/org/chromium/ui/modelutil/SimpleRecyclerViewAdapterTest.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.ui.modelutil;
+
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.view.View;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import org.chromium.base.test.BaseRobolectricTestRunner;
+import org.chromium.ui.modelutil.MVCListAdapter.ModelList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Tests to ensure/validate SimpleRecyclerViewAdapter behavior.
+ */
+@RunWith(BaseRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class SimpleRecyclerViewAdapterTest {
+    private static final PropertyModel.WritableIntPropertyKey INT_PROPERTY =
+            new PropertyModel.WritableIntPropertyKey();
+    private static final Integer VIEW_TYPE_1 = 1;
+    private static final Integer VIEW_TYPE_2 = 2;
+    private static final Integer VIEW_TYPE_3 = 3;
+
+    private ModelList mModelList;
+    private PropertyModel mModel;
+
+    // Mockito Spies allow us to intercept calls to parent class.
+    private SimpleRecyclerViewAdapter mSpyAdapter;
+
+    @Mock
+    View mMockView;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mModel = new PropertyModel(INT_PROPERTY);
+        mModelList = new ModelList();
+
+        // Note: this behaves both like a mock and a real object.
+        // Methods calls can be mocked or tracked to validate class behavior.
+        mSpyAdapter = Mockito.mock(SimpleRecyclerViewAdapter.class,
+                Mockito.withSettings()
+                        .useConstructor(mModelList)
+                        .defaultAnswer(Mockito.CALLS_REAL_METHODS));
+
+        mSpyAdapter.registerType(VIEW_TYPE_1, parent -> mMockView, (m, v, p) -> {});
+        mSpyAdapter.registerType(VIEW_TYPE_2, parent -> mMockView, (m, v, p) -> {});
+        mSpyAdapter.registerType(VIEW_TYPE_3, parent -> mMockView, (m, v, p) -> {});
+    }
+
+    @Test
+    public void testObserver_listModelItemsAdded() {
+        mModelList.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(0, 1);
+        mModelList.add(new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(1, 1);
+    }
+
+    @Test
+    public void testObserver_listModelItemsAddedInBatch() {
+        mModelList.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(0, 1);
+        List<ModelListAdapter.ListItem> items = new ArrayList<>();
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_3, mModel));
+        mModelList.addAll(items);
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(1, 3);
+    }
+
+    @Test
+    public void testObserver_listModelItemsSet() {
+        List<ModelListAdapter.ListItem> items = new ArrayList<>();
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_3, mModel));
+        mModelList.set(items);
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(0, 3);
+    }
+
+    @Test
+    public void testObserver_listModelItemsRemove() {
+        List<ModelListAdapter.ListItem> items = new ArrayList<>();
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_3, mModel));
+        mModelList.set(items);
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(0, 3);
+        mModelList.removeRange(0, 2);
+        verify(mSpyAdapter, times(1)).notifyItemRangeRemoved(0, 2);
+    }
+
+    @Test
+    public void testObserver_listModelItemsClear() {
+        List<ModelListAdapter.ListItem> items = new ArrayList<>();
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_3, mModel));
+        mModelList.set(items);
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(0, 3);
+        mModelList.clear();
+        verify(mSpyAdapter, times(1)).notifyItemRangeRemoved(0, 3);
+    }
+
+    @Test
+    public void testObserver_listModelItemMoved() {
+        List<ModelListAdapter.ListItem> items = new ArrayList<>();
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_3, mModel));
+        mModelList.set(items);
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(0, 3);
+
+        mModelList.move(1, 2);
+        verify(mSpyAdapter, times(1)).notifyItemMoved(1, 2);
+    }
+
+    @Test
+    public void testObserver_listModelItemUpdated() {
+        List<ModelListAdapter.ListItem> items = new ArrayList<>();
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_1, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        items.add(new ModelListAdapter.ListItem(VIEW_TYPE_3, mModel));
+        mModelList.set(items);
+        verify(mSpyAdapter, times(1)).notifyItemRangeInserted(0, 3);
+
+        mModelList.update(1, new ModelListAdapter.ListItem(VIEW_TYPE_2, mModel));
+        verify(mSpyAdapter, times(1)).notifyItemRangeChanged(1, 1);
+    }
+}