Cap widget bitmap usage by screen size (issue 6464700)

Change-Id: I04e16223861a88d40ad757afa086a0f92e84493b

Author: Adam Cohen

core/java/android/appwidget/AppWidgetManager.java

@@ -320,6 +320,10 @@ private AppWidgetManager(Context context) {
      * It is okay to call this method both inside an {@link #ACTION_APPWIDGET_UPDATE} broadcast,
      * and outside of the handler.
      * This method will only work when called from the uid that owns the AppWidget provider.
+     * 
+     * <p>
+     * The total Bitmap memory used by the RemoteViews object cannot exceed that required to
+     * fill the screen once, ie. (screen width x screen height x 4) bytes.
      *
      * @param appWidgetIds     The AppWidget instances for which to set the RemoteViews.
      * @param views         The RemoteViews object to show.
@@ -385,6 +389,10 @@ public Bundle getAppWidgetOptions(int appWidgetId) {
      * and outside of the handler.
      * This method will only work when called from the uid that owns the AppWidget provider.
      *
+     * <p>
+     * The total Bitmap memory used by the RemoteViews object cannot exceed that required to
+     * fill the screen once, ie. (screen width x screen height x 4) bytes.
+     *
      * @param appWidgetId      The AppWidget instance for which to set the RemoteViews.
      * @param views         The RemoteViews object to show.
      */

core/java/android/widget/RemoteViews.java

@@ -1445,7 +1445,8 @@ private void setBitmapCache(BitmapCache bitmapCache) {
     /**
      * Returns an estimate of the bitmap heap memory usage for this RemoteViews.
      */
-    int estimateMemoryUsage() {
+    /** @hide */
+    public int estimateMemoryUsage() {
         return mMemoryUsageCounter.getMemoryUsage();
     }
 

services/java/com/android/server/AppWidgetServiceImpl.java

@@ -49,6 +49,7 @@
 import android.util.Slog;
 import android.util.TypedValue;
 import android.util.Xml;
+import android.view.WindowManager;
 import android.widget.RemoteViews;
 
 import com.android.internal.appwidget.IAppWidgetHost;
@@ -171,6 +172,7 @@ public void disconnect() {
     boolean mSafeMode;
     int mUserId;
     boolean mStateLoaded;
+    int mMaxWidgetBitmapMemory;
 
     // These are for debugging only -- widgets are going missing in some rare instances
     ArrayList<Provider> mDeletedProviders = new ArrayList<Provider>();
@@ -181,6 +183,14 @@ public void disconnect() {
         mPm = AppGlobals.getPackageManager();
         mAlarmManager = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
         mUserId = userId;
+        computeMaximumWidgetBitmapMemory();
+    }
+
+    void computeMaximumWidgetBitmapMemory() {
+        WindowManager wm = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
+        int height = wm.getDefaultDisplay().getRawHeight();
+        int width = wm.getDefaultDisplay().getRawWidth();
+        mMaxWidgetBitmapMemory = 4 * width * height;
     }
 
     public void systemReady(boolean safeMode) {
@@ -806,6 +816,15 @@ public void updateAppWidgetIds(int[] appWidgetIds, RemoteViews views) {
         if (appWidgetIds == null) {
             return;
         }
+
+        int bitmapMemoryUsage = views.estimateMemoryUsage();
+        if (bitmapMemoryUsage > mMaxWidgetBitmapMemory) {
+            throw new IllegalArgumentException("RemoteViews for widget update exceeds maximum" +
+                    " bitmap memory usage (used: " + bitmapMemoryUsage + ", max: " +
+                    mMaxWidgetBitmapMemory + ") The total memory cannot exceed that required to" +
+                    " fill the device's screen once.");
+        }
+
         if (appWidgetIds.length == 0) {
             return;
         }