Remove flicker when multiple apps are added/removed/updated on widget tray

Bug: 36718342

1.The flicker was also happening partially because notifyWidgetProviderChanged
callback also made the entire widget list to update in addition to
packageManager update.

2. Now that adapter calls notifyItemInserted, Removed, the recycler
view uses it's internal animation to elegantly move items or insert
them. (added benefit!)

3. Added tests for WidgetsListAdapterTest

$ adb shell am instrument -w -e class com.android.launcher3.widget.WidgetsListAdapterTest com.google.android.apps.nexuslauncher.tests/android.support.test.runner.AndroidJUnitRunner

com.android.launcher3.widget.WidgetsListAdapterTest:.

Time: 0.337

OK (6 test)

Change-Id: I0818d546532631bf889fae560118decff64ec5a4
Signed-off-by: Hyunyoung Song <hyunyoungs@google.com>

1 files changed, 149 insertions, 0 deletions

diff --git a/tests/src/com/android/launcher3/widget/WidgetsListAdapterTest.java b/tests/src/com/android/launcher3/widget/WidgetsListAdapterTest.java
new file mode 100644
index 000000000..40b65e4fb
--- /dev/null
+++ b/tests/src/com/android/launcher3/widget/WidgetsListAdapterTest.java
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget;
+
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.graphics.Bitmap;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import android.view.LayoutInflater;
+
+import com.android.launcher3.IconCache;
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.LauncherAppWidgetProviderInfo;
+import com.android.launcher3.WidgetPreviewLoader;
+import com.android.launcher3.compat.AlphabeticIndexCompat;
+import com.android.launcher3.compat.AppWidgetManagerCompat;
+import com.android.launcher3.model.PackageItemInfo;
+import com.android.launcher3.model.WidgetItem;
+import com.android.launcher3.util.MultiHashMap;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class WidgetsListAdapterTest {
+
+    private final String TAG = "WidgetsListAdapterTest";
+
+    @Mock private LayoutInflater mMockLayoutInflater;
+    @Mock private WidgetPreviewLoader mMockWidgetCache;
+    @Mock private WidgetsDiffReporter.NotifyListener mListener;
+    @Mock private IconCache mIconCache;
+
+    private WidgetsListAdapter mAdapter;
+    private AlphabeticIndexCompat mIndexCompat;
+    private InvariantDeviceProfile mTestProfile;
+    private Context mContext;
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+        mContext = InstrumentationRegistry.getTargetContext();
+        mTestProfile = new InvariantDeviceProfile();
+        mTestProfile.numRows = 5;
+        mTestProfile.numColumns = 5;
+        mIndexCompat = new AlphabeticIndexCompat(mContext);
+        WidgetsDiffReporter reporter = new WidgetsDiffReporter(mIconCache);
+        reporter.setListener(mListener);
+        mAdapter = new WidgetsListAdapter(mContext, mMockLayoutInflater, mMockWidgetCache,
+                mIndexCompat, null, null, reporter);
+    }
+
+    @Test
+    public void test_notifyDataSetChanged() throws Exception {
+        mAdapter.setWidgets(generateSampleMap(1));
+        verify(mListener, times(1)).notifyDataSetChanged();
+    }
+
+    @Test
+    public void test_notifyItemInserted() throws Exception {
+        mAdapter.setWidgets(generateSampleMap(1));
+        mAdapter.setWidgets(generateSampleMap(2));
+        verify(mListener, times(1)).notifyDataSetChanged();
+        verify(mListener, times(1)).notifyItemInserted(1);
+    }
+
+    @Test
+    public void test_notifyItemRemoved() throws Exception {
+        mAdapter.setWidgets(generateSampleMap(2));
+        mAdapter.setWidgets(generateSampleMap(1));
+        verify(mListener, times(1)).notifyDataSetChanged();
+        verify(mListener, times(1)).notifyItemRemoved(1);
+    }
+
+    @Test
+    public void testNotifyItemChanged_PackageIconDiff() throws Exception {
+        mAdapter.setWidgets(generateSampleMap(1));
+        mAdapter.setWidgets(generateSampleMap(1));
+        verify(mListener, times(1)).notifyDataSetChanged();
+        verify(mListener, times(1)).notifyItemChanged(0);
+    }
+
+    @Test
+    public void testNotifyItemChanged_widgetItemInfoDiff() throws Exception {
+        // TODO: same package name but item number changed
+    }
+
+    @Test
+    public void testNotifyItemInsertedRemoved_hodgepodge() throws Exception {
+        // TODO: insert and remove combined.          curMap
+        // newMap [A, C, D]                           [A, B, E]
+        // B - C < 0, removed B from index 1          [A, E]
+        // E - C > 0, C inserted to index 1           [A, C, E]
+        // E - D > 0, D inserted to index 2           [A, C, D, E]
+        // E - null = -1, E deleted from index 3      [A, C, D]
+    }
+
+    /**
+     * Helper method to generate the sample widget model map that can be used for the tests
+     * @param num the number of WidgetItem the map should contain
+     * @return
+     */
+    private MultiHashMap<PackageItemInfo, WidgetItem> generateSampleMap(int num) {
+        MultiHashMap<PackageItemInfo, WidgetItem> newMap = new MultiHashMap();
+        if (num <= 0) return newMap;
+
+        PackageManager pm = mContext.getPackageManager();
+        AppWidgetManagerCompat widgetManager = AppWidgetManagerCompat.getInstance(mContext);
+        for (AppWidgetProviderInfo widgetInfo : widgetManager.getAllProviders(null)) {
+            WidgetItem wi = new WidgetItem(LauncherAppWidgetProviderInfo
+                    .fromProviderInfo(mContext, widgetInfo), pm, mTestProfile);
+
+            PackageItemInfo pInfo = new PackageItemInfo(wi.componentName.getPackageName());
+            pInfo.title = pInfo.packageName;
+            pInfo.user = wi.user;
+            pInfo.iconBitmap = Bitmap.createBitmap(10, 10, Bitmap.Config.ALPHA_8);
+            newMap.addToList(pInfo, wi);
+            if (newMap.size() == num) {
+                break;
+            }
+        }
+        return newMap;
+    }
+}