Skip redundant SuggestionLoader run during app start.

also skip DiffUtil when drawing first frame.


Fix: 34103984
Test: make RunSettingsRoboTests
Change-Id: I4891d1bca1f17c437444761eaf3002624934014d

src/com/android/settings/SettingsActivity.java

@@ -527,8 +527,9 @@ public class SettingsActivity extends SettingsDrawerActivity
             }
         }
 
-        if (DEBUG_TIMING) Log.d(LOG_TAG, "onCreate took " + (System.currentTimeMillis() - startTime)
-                + " ms");
+        if (DEBUG_TIMING) {
+            Log.d(LOG_TAG, "onCreate took " + (System.currentTimeMillis() - startTime) + " ms");
+        }
     }
 
     public void setDisplaySearchMenu(boolean displaySearch) {

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

@@ -63,6 +63,7 @@ public class DashboardAdapter extends RecyclerView.Adapter<DashboardAdapter.Dash
     private final MetricsFeatureProvider mMetricsFeatureProvider;
     private final DashboardFeatureProvider mDashboardFeatureProvider;
     private SuggestionParser mSuggestionParser;
+    private boolean mFirstFrameDrawn;
 
     @VisibleForTesting
     DashboardData mDashboardData;
@@ -162,6 +163,15 @@ public class DashboardAdapter extends RecyclerView.Adapter<DashboardAdapter.Dash
         notifyDashboardDataChanged(prevData);
     }
 
+    public void setCategory(List<DashboardCategory> category) {
+        final DashboardData prevData = mDashboardData;
+        Log.d(TAG, "adapter setCategory called");
+        mDashboardData = new DashboardData.Builder(prevData)
+                .setCategories(category)
+                .build();
+        notifyDashboardDataChanged(prevData);
+    }
+
     public void setConditions(List<Condition> conditions) {
         final DashboardData prevData = mDashboardData;
         Log.d(TAG, "adapter setConditions called");
@@ -304,11 +314,12 @@ public class DashboardAdapter extends RecyclerView.Adapter<DashboardAdapter.Dash
     }
 
     private void notifyDashboardDataChanged(DashboardData prevData) {
-        if (prevData != null) {
+        if (mFirstFrameDrawn && prevData != null) {
             final DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(new DashboardData
                     .ItemsDataDiffCallback(prevData.getItemList(), mDashboardData.getItemList()));
             diffResult.dispatchUpdatesTo(this);
         } else {
+            mFirstFrameDrawn = true;
             notifyDataSetChanged();
         }
     }

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

@@ -27,6 +27,7 @@ import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.settings.R;
 import com.android.settings.SettingsActivity;
@@ -231,26 +232,25 @@ public class DashboardSummary extends InstrumentedFragment
             Log.d(TAG, "onViewCreated took "
                     + (System.currentTimeMillis() - startTime) + " ms");
         }
-        rebuildUI();
-    }
-
-    private void rebuildUI() {
-        if (!isAdded()) {
-            Log.w(TAG, "Cannot build the DashboardSummary UI yet as the Fragment is not added");
-            return;
+        rebuildUI(true /* rebuildSuggestions */);
     }
 
+    private void rebuildUI(boolean rebuildSuggestions) {
+        if (rebuildSuggestions) {
             // recheck to see if any suggestions have been changed.
             new SuggestionLoader().execute();
             // Set categories on their own if loading suggestions takes too long.
             mHandler.postDelayed(() -> {
                 updateCategoryAndSuggestion(null /* tiles */);
             }, MAX_WAIT_MILLIS);
+        } else {
+            updateCategoryAndSuggestion(null /* tiles */);
+        }
     }
 
     @Override
     public void onCategoriesChanged() {
-        rebuildUI();
+        rebuildUI(false /* rebuildSuggestions */);
     }
 
     @Override
@@ -264,7 +264,6 @@ public class DashboardSummary extends InstrumentedFragment
     }
 
     private class SuggestionLoader extends AsyncTask<Void, Void, List<Tile>> {
-
         @Override
         protected List<Tile> doInBackground(Void... params) {
             final Context context = getContext();
@@ -307,7 +306,7 @@ public class DashboardSummary extends InstrumentedFragment
     }
 
     @VisibleForTesting
-    void updateCategoryAndSuggestion(List<Tile> tiles) {
+    void updateCategoryAndSuggestion(List<Tile> suggestions) {
         final Activity activity = getActivity();
         if (activity == null) {
             return;
@@ -319,10 +318,14 @@ public class DashboardSummary extends InstrumentedFragment
             List<DashboardCategory> categories = new ArrayList<>();
             categories.add(mDashboardFeatureProvider.getTilesForCategory(
                     CategoryKey.CATEGORY_HOMEPAGE));
-            mAdapter.setCategoriesAndSuggestions(categories, tiles);
+            if (suggestions != null) {
+                mAdapter.setCategoriesAndSuggestions(categories, suggestions);
+            } else {
+                mAdapter.setCategory(categories);
+            }
         } else {
             mAdapter.setCategoriesAndSuggestions(
-                    ((SettingsActivity) activity).getDashboardCategories(), tiles);
+                    ((SettingsActivity) activity).getDashboardCategories(), suggestions);
         }
     }
 }

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

@@ -17,8 +17,8 @@
 package com.android.settings.dashboard;
 
 import android.app.Activity;
-
 import android.support.v7.widget.LinearLayoutManager;
+
 import com.android.settings.SettingsRobolectricTestRunner;
 import com.android.settings.TestConfig;
 import com.android.settings.dashboard.conditional.ConditionManager;
@@ -33,6 +33,7 @@ import org.mockito.MockitoAnnotations;
 import org.robolectric.annotation.Config;
 import org.robolectric.util.ReflectionHelpers;
 
+import static org.mockito.Matchers.anyList;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -90,4 +91,13 @@ public class DashboardSummaryTest {
         mSummary.onConditionsChanged();
         verify(mDashboard, never()).scrollToPosition(0);
     }
+
+    @Test
+    public void onCategoryChanged_updateCategoryOnly() {
+        doReturn(mock(Activity.class)).when(mSummary).getActivity();
+        when(mDashboardFeatureProvider.isEnabled()).thenReturn(true);
+
+        mSummary.onCategoriesChanged();
+        verify(mAdapter).setCategory(anyList());
+    }
 }