Fix ConcurrentModificationException in SummaryLoader.

When the dashboard summary is being initialized, it will rebuild the UI
while the summary loader tries to to go through the tiles to update the
summary. Both is being done on a separate backgroud thread, and it will
run into concurrent modification issue if the thread is being swapped
while one is looping through the list.

Instead of letting clients access the list of tiles directly, add a
getter method in DashboardCategory to get a copy of the list of tiles
for all read-only operations.

Change-Id: I479669abd8d1d0a8ee9a4113d8ad2244da56f4d8
Fixes: 69677575
Test: make RunSettingsRoboTests

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

@@ -222,14 +222,12 @@ public class DashboardAdapterTest {
         doReturn(mockTypedArray).when(mContext).obtainStyledAttributes(any(int[].class));
         doReturn(0x89000000).when(mockTypedArray).getColor(anyInt(), anyInt());
 
-        final DashboardCategory category = mock(DashboardCategory.class);
-        final List<Tile> tiles = new ArrayList<>();
+        final DashboardCategory category = new DashboardCategory();
         final Icon mockIcon = mock(Icon.class);
         final Tile tile = new Tile();
         tile.isIconTintable = true;
         tile.icon = mockIcon;
-        tiles.add(tile);
-        category.tiles = tiles;
+        category.addTile(tile);
 
         mDashboardAdapter.setCategory(category);
 
@@ -250,10 +248,8 @@ public class DashboardAdapterTest {
     public void testBindConditionAndSuggestion_shouldSetSuggestionAdapterAndNoCrash() {
         mDashboardAdapter = new DashboardAdapter(mContext, null, null, null, null, null);
         final List<Tile> suggestions = makeSuggestions("pkg1");
-        final DashboardCategory category = mock(DashboardCategory.class);
-        final List<Tile> tiles = new ArrayList<>();
-        tiles.add(mock(Tile.class));
-        category.tiles = tiles;
+        final DashboardCategory category = new DashboardCategory();
+        category.addTile(mock(Tile.class));
 
         mDashboardAdapter.setCategoriesAndSuggestions(category, suggestions);
 
@@ -277,10 +273,8 @@ public class DashboardAdapterTest {
     public void testBindConditionAndSuggestion_v2_shouldSetSuggestionAdapterAndNoCrash() {
         mDashboardAdapter = new DashboardAdapter(mContext, null, null, null, null, null);
         final List<Suggestion> suggestions = makeSuggestionsV2("pkg1");
-        final DashboardCategory category = mock(DashboardCategory.class);
-        final List<Tile> tiles = new ArrayList<>();
-        tiles.add(mock(Tile.class));
-        category.tiles = tiles;
+        final DashboardCategory category = new DashboardCategory();
+        category.addTile(mock(Tile.class));
 
         mDashboardAdapter.setSuggestionsV2(suggestions);
 
@@ -310,10 +304,8 @@ public class DashboardAdapterTest {
                 null /* SuggestionDismissController.Callback */);
 
         final List<Tile> suggestions = new ArrayList<>();
-        final DashboardCategory category = mock(DashboardCategory.class);
-        final List<Tile> tiles = new ArrayList<>();
-        tiles.add(mock(Tile.class));
-        category.tiles = tiles;
+        final DashboardCategory category = new DashboardCategory();
+        category.addTile(mock(Tile.class));
         mDashboardAdapter.setCategoriesAndSuggestions(category, suggestions);
 
         final RecyclerView data = mock(RecyclerView.class);

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

@@ -57,13 +57,12 @@ public class DashboardDataTest {
     private DashboardData mDashboardDataWithOneConditions;
     private DashboardData mDashboardDataWithTwoConditions;
     private DashboardData mDashboardDataWithNoItems;
+    private DashboardCategory mDashboardCategory;
     @Mock
     private Tile mTestCategoryTile;
     @Mock
     private Tile mTestSuggestion;
     @Mock
-    private DashboardCategory mDashboardCategory;
-    @Mock
     private Condition mTestCondition;
     @Mock
     private Condition mSecondCondition; // condition used to test insert in DiffUtil
@@ -72,6 +71,8 @@ public class DashboardDataTest {
     public void SetUp() {
         MockitoAnnotations.initMocks(this);
 
+        mDashboardCategory = new DashboardCategory();
+
         // Build suggestions
         final List<Tile> suggestions = new ArrayList<>();
         mTestSuggestion.title = TEST_SUGGESTION_TITLE;
@@ -91,8 +92,8 @@ public class DashboardDataTest {
         // Build category
         mTestCategoryTile.title = TEST_CATEGORY_TILE_TITLE;
         mDashboardCategory.title = "test";
-        mDashboardCategory.tiles = new ArrayList<>();
-        mDashboardCategory.tiles.add(mTestCategoryTile);
+
+        mDashboardCategory.addTile(mTestCategoryTile);
 
         // Build DashboardData
         mDashboardDataWithOneConditions = new DashboardData.Builder()

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

@@ -431,7 +431,7 @@ public class DashboardFeatureProviderImplTest {
         mImpl = new DashboardFeatureProviderImpl(mActivity);
         ReflectionHelpers.setField(mImpl, "mCategoryManager", mCategoryManager);
         final DashboardCategory category = new DashboardCategory();
-        category.tiles.add(new Tile());
+        category.addTile(new Tile());
         when(mCategoryManager
                 .getTilesByCategory(any(Context.class), eq(CategoryKey.CATEGORY_HOMEPAGE)))
                 .thenReturn(category);

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

@@ -64,9 +64,8 @@ public class DashboardFragmentTest {
     @Mock(answer = Answers.RETURNS_DEEP_STUBS)
     private Context mContext;
     @Mock
-    private DashboardCategory mDashboardCategory;
-    @Mock
     private FakeFeatureFactory mFakeFeatureFactory;
+    private DashboardCategory mDashboardCategory;
     private TestFragment mTestFragment;
 
     @Before
@@ -74,8 +73,8 @@ public class DashboardFragmentTest {
         MockitoAnnotations.initMocks(this);
         FakeFeatureFactory.setupForTest(mContext);
         mFakeFeatureFactory = (FakeFeatureFactory) FeatureFactory.getFactory(mContext);
-        mDashboardCategory.tiles = new ArrayList<>();
-        mDashboardCategory.tiles.add(new Tile());
+        mDashboardCategory = new DashboardCategory();
+        mDashboardCategory.addTile(new Tile());
         mTestFragment = new TestFragment(ShadowApplication.getInstance().getApplicationContext());
         when(mFakeFeatureFactory.dashboardFeatureProvider
                 .getTilesForCategory(nullable(String.class)))
@@ -117,7 +116,7 @@ public class DashboardFragmentTest {
 
     @Test
     public void displayTilesAsPreference_withEmptyCategory_shouldNotAddTiles() {
-        mDashboardCategory.tiles = null;
+        mDashboardCategory.removeTile(0);
         mTestFragment.onCreatePreferences(new Bundle(), "rootKey");
 
         verify(mTestFragment.mScreen, never()).addPreference(nullable(Preference.class));