Bug 826639 - Force pending about:home updates to happen onDraw. r=lucasr

mobile/android/base/widget/AboutHomeContent.java

@@ -14,6 +14,7 @@ import org.mozilla.gecko.util.ThreadUtils;
 
 import android.content.Context;
 import android.database.ContentObserver;
+import android.graphics.Canvas;
 import android.util.AttributeSet;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.ContextMenu.ContextMenuInfo;
@@ -45,6 +46,7 @@ public class AboutHomeContent extends ScrollView
     private Context mContext;
     private BrowserApp mActivity;
     private UriLoadCallback mUriLoadCallback = null;
+    private EnumSet<UpdateFlags> mPendingUpdates = EnumSet.noneOf(UpdateFlags.class);
 
     private ContentObserver mTabsContentObserver = null;
 
@@ -155,19 +157,44 @@ public class AboutHomeContent extends ScrollView
     }
 
     public void update(final EnumSet<UpdateFlags> flags) {
-        ThreadUtils.postToBackgroundThread(new Runnable() {
+        synchronized (mPendingUpdates) {
+            for (UpdateFlags flag : flags) {
+                if (!mPendingUpdates.contains(flag))
+                    mPendingUpdates.add(flag);
+            }
+        }
+    }
+
+    @Override
+    protected void dispatchDraw(Canvas canvas) {
+        super.dispatchDraw(canvas);
+        // if any updates are pending, process them on a background thread
+        processPendingUpdates();
+    }
+
+    void processPendingUpdates() {
+        // during startup, this may be called before init()
+        final EnumSet<UpdateFlags> copiedUpdates;
+        synchronized (mPendingUpdates) {
+            if (mPendingUpdates.isEmpty())
+                return;
+            copiedUpdates = mPendingUpdates.clone();
+            mPendingUpdates = EnumSet.noneOf(UpdateFlags.class);
+        }
+
+        ThreadUtils.getBackgroundHandler().post(new Runnable() {
             @Override
             public void run() {
-                if (flags.contains(UpdateFlags.TOP_SITES))
+                if (copiedUpdates.contains(UpdateFlags.TOP_SITES))
                     loadTopSites();
 
-                if (flags.contains(UpdateFlags.PREVIOUS_TABS))
+                if (copiedUpdates.contains(UpdateFlags.PREVIOUS_TABS))
                     readLastTabs();
 
-                if (flags.contains(UpdateFlags.RECOMMENDED_ADDONS))
+                if (copiedUpdates.contains(UpdateFlags.RECOMMENDED_ADDONS))
                     readRecommendedAddons();
 
-                if (flags.contains(UpdateFlags.REMOTE_TABS))
+                if (copiedUpdates.contains(UpdateFlags.REMOTE_TABS))
                     loadRemoteTabs();
             }
         });

mobile/android/base/widget/TopSitesView.java

@@ -255,6 +255,7 @@ public class TopSitesView extends GridView {
             } catch (OutOfMemoryError oom) {
                 Log.e(LOGTAG, "Unable to load thumbnail bitmap", oom);
                 thumbnailView.setImageResource(R.drawable.abouthome_thumbnail_bg);
+                thumbnailView.setBackgroundColor(mThumbnailBackground);
                 thumbnailView.setScaleType(ImageView.ScaleType.FIT_CENTER);
             }
         }
@@ -274,6 +275,7 @@ public class TopSitesView extends GridView {
             if (TextUtils.isEmpty(url)) {
                 holder.thumbnailView.setImageResource(R.drawable.abouthome_thumbnail_add);
                 holder.thumbnailView.setScaleType(ImageView.ScaleType.FIT_CENTER);
+                holder.thumbnailView.setBackgroundColor(mThumbnailBackground);
             } else {
                 displayThumbnail(view, thumbnails.get(url));
             }