am dbf3d3ac: am af1f42be: Fix issue #2271668: Live Wallpaper Force-Close when changing from live wallpaper to picasa wallpaper

Merge commit 'dbf3d3acc18f86a671096f1626d80d055bc36e11' into eclair-mr2-plus-aosp

* commit 'dbf3d3acc18f86a671096f1626d80d055bc36e11':
  Fix issue #2271668: Live Wallpaper Force-Close when changing from live wallpaper to picasa wallpaper

core/java/android/service/wallpaper/WallpaperService.java

@@ -44,6 +44,8 @@ import android.view.ViewRoot;
 import android.view.WindowManager;
 import android.view.WindowManagerImpl;
 
+import java.util.ArrayList;
+
 /**
  * A wallpaper service is responsible for showing a live wallpaper behind
  * applications that would like to sit on top of it.  This service object
@@ -83,6 +85,8 @@ public abstract class WallpaperService extends Service {
     private static final int MSG_TOUCH_EVENT = 10040;
     
     private Looper mCallbackLooper;
+    private final ArrayList<Engine> mActiveEngines
+            = new ArrayList<Engine>();
     
     static final class WallpaperCommand {
         String action;
@@ -596,8 +600,10 @@ public abstract class WallpaperService extends Service {
         }
         
         void doVisibilityChanged(boolean visible) {
-            mVisible = visible;
-            reportVisibility();
+            if (!mDestroyed) {
+                mVisible = visible;
+                reportVisibility();
+            }
         }
         
         void reportVisibility() {
@@ -666,6 +672,10 @@ public abstract class WallpaperService extends Service {
         }
         
         void detach() {
+            if (mDestroyed) {
+                return;
+            }
+            
             mDestroyed = true;
             
             if (mVisible) {
@@ -773,10 +783,12 @@ public abstract class WallpaperService extends Service {
                     }
                     Engine engine = onCreateEngine();
                     mEngine = engine;
+                    mActiveEngines.add(engine);
                     engine.attach(this);
                     return;
                 }
                 case DO_DETACH: {
+                    mActiveEngines.remove(mEngine);
                     mEngine.detach();
                     return;
                 }
@@ -844,6 +856,20 @@ public abstract class WallpaperService extends Service {
         }
     }
     
+    @Override
+    public void onCreate() {
+        super.onCreate();
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        for (int i=0; i<mActiveEngines.size(); i++) {
+            mActiveEngines.get(i).detach();
+        }
+        mActiveEngines.clear();
+    }
+
     /**
      * Implement to return the implementation of the internal accessibility
      * service interface.  Subclasses should not override.