Add DashboardItemAnimator to stop flash

When there is no offset change for identical holder in
animateChange, simply return and don't invoke the
resetAnimation.

Bug: 33198024
Test: make RunSettingsRoboTests
Change-Id: Ib83363873bc5f51e5bd71af5a013ee0756728d1a

src/com/android/settings/dashboard/DashboardAdapter.java

@@ -165,7 +165,7 @@ public class DashboardAdapter extends RecyclerView.Adapter<DashboardAdapter.Dash
         if (position != DashboardData.POSITION_NOT_FOUND) {
             // Since usually tile in parameter and tile in mCategories are same instance,
             // which is hard to be detected by DiffUtil, so we notifyItemChanged directly.
-            notifyItemChanged(position);
+            notifyItemChanged(position, mDashboardData.getItemTypeByPosition(position));
         }
     }
 

src/com/android/settings/dashboard/DashboardItemAnimator.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2016 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.settings.dashboard;
+
+import android.support.v4.view.ViewCompat;
+import android.support.v7.widget.DefaultItemAnimator;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+
+public class DashboardItemAnimator extends DefaultItemAnimator {
+
+    @Override
+    public boolean animateChange(ViewHolder oldHolder, ViewHolder newHolder, int fromX, int fromY,
+            int toX, int toY) {
+        if (oldHolder == newHolder) {
+            fromX += ViewCompat.getTranslationX(oldHolder.itemView);
+            fromY += ViewCompat.getTranslationY(oldHolder.itemView);
+            if (fromX == toX && fromY == toY) {
+                dispatchMoveFinished(oldHolder);
+                return false;
+            }
+        }
+        return super.animateChange(oldHolder, newHolder, fromX, fromY, toX, toY);
+    }
+}

src/com/android/settings/dashboard/DashboardSummary.java

@@ -22,6 +22,7 @@ import android.os.AsyncTask;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.SimpleItemAnimator;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -222,6 +223,7 @@ public class DashboardSummary extends InstrumentedFragment
         mAdapter = new DashboardAdapter(getContext(), mSuggestionParser, mMetricsFeatureProvider,
                 bundle, mConditionManager.getConditions());
         mDashboard.setAdapter(mAdapter);
+        mDashboard.setItemAnimator(new DashboardItemAnimator());
         mSummaryLoader.setSummaryConsumer(mAdapter);
         ConditionAdapterUtils.addDismiss(mDashboard);
         if (DEBUG_TIMING) {

tests/robotests/src/com/android/settings/dashboard/DashboardItemAnimatorTest.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2016 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.settings.dashboard;
+
+import android.content.Context;
+import android.widget.TextView;
+import com.android.settings.SettingsRobolectricTestRunner;
+import com.android.settings.TestConfig;
+import com.android.settings.dashboard.SupportItemAdapter.ViewHolder;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+import org.robolectric.shadows.ShadowApplication;
+
+import static com.google.common.truth.Truth.assertThat;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class DashboardItemAnimatorTest {
+
+    private DashboardItemAnimator mDashboardItemAnimator;
+    private ViewHolder mViewHolder;
+
+    @Before
+    public void SetUp() {
+        final Context context = ShadowApplication.getInstance().getApplicationContext();
+        mDashboardItemAnimator = new DashboardItemAnimator();
+        mViewHolder = new ViewHolder(new TextView(context));
+    }
+
+    @Test
+    public void testAnimateChange_NoOffset_NoPendingAnimation() {
+        final boolean hasPendingAnimation = mDashboardItemAnimator
+                .animateChange(mViewHolder, mViewHolder, 0, 1, 0, 1);
+        assertThat(hasPendingAnimation).isFalse();
+    }
+
+    @Test
+    public void testAnimateChange_HasOffset_HasPendingAnimation() {
+        final boolean hasPendingAnimation = mDashboardItemAnimator
+                .animateChange(mViewHolder, mViewHolder, 0, 0, 1, 1);
+        assertThat(hasPendingAnimation).isTrue();
+    }
+
+}