DO NOT MERGE -- Only use saved surface if started by launcher or moved to front

am: 813be138ae

Change-Id: Id64071882a0b90212b92234a4d0bdc67f2ee5e1a

core/java/android/view/IWindowManager.aidl

@@ -173,7 +173,7 @@ interface IWindowManager
             in CompatibilityInfo compatInfo, CharSequence nonLocalizedLabel, int labelRes,
             int icon, int logo, int windowFlags, IBinder transferFrom, boolean createIfNeeded);
     void setAppVisibility(IBinder token, boolean visible);
-    void notifyAppResumed(IBinder token, boolean wasStopped);
+    void notifyAppResumed(IBinder token, boolean wasStopped, boolean allowSavedSurface);
     void notifyAppStopped(IBinder token);
     void startAppFreezingScreen(IBinder token, int configChanges);
     void stopAppFreezingScreen(IBinder token, boolean force);

services/core/java/com/android/server/am/ActivityRecord.java

@@ -750,6 +750,14 @@ final class ActivityRecord {
                 && intent.getType() == null;
     }
 
+    static boolean isMainIntent(Intent intent) {
+        return Intent.ACTION_MAIN.equals(intent.getAction())
+                && intent.hasCategory(Intent.CATEGORY_LAUNCHER)
+                && intent.getCategories().size() == 1
+                && intent.getData() == null
+                && intent.getType() == null;
+    }
+
     private boolean canLaunchHomeActivity(int uid, ActivityRecord sourceRecord) {
         if (uid == Process.myUid() || uid == 0) {
             // System process can launch home activity.

services/core/java/com/android/server/am/ActivityStack.java

@@ -2485,13 +2485,25 @@ final class ActivityStack {
                     }
                 }
 
+                boolean allowSavedSurface = true;
                 if (next.newIntents != null) {
+                    // Restrict saved surface to launcher start, or there is no intent at all
+                    // (eg. task being brought to front). If the intent is something else,
+                    // likely the app is going to show some specific page or view, instead of
+                    // what's left last time.
+                    for (int i = next.newIntents.size() - 1; i >= 0; i--) {
+                        final Intent intent = next.newIntents.get(i);
+                        if (intent != null && !ActivityRecord.isMainIntent(intent)) {
+                            allowSavedSurface = false;
+                            break;
+                        }
+                    }
                     next.app.thread.scheduleNewIntent(next.newIntents, next.appToken);
                 }
 
                 // Well the app will no longer be stopped.
                 // Clear app token stopped state in window manager if needed.
-                mWindowManager.notifyAppResumed(next.appToken, next.stopped);
+                mWindowManager.notifyAppResumed(next.appToken, next.stopped, allowSavedSurface);
 
                 EventLog.writeEvent(EventLogTags.AM_RESUME_ACTIVITY, next.userId,
                         System.identityHashCode(next), next.task.taskId, next.shortComponentName);

services/core/java/com/android/server/wm/AppWindowToken.java

@@ -439,12 +439,16 @@ class AppWindowToken extends WindowToken {
      * Notify that the app is now resumed, and it was not stopped before, perform a clean
      * up of the surfaces
      */
-    void notifyAppResumed(boolean wasStopped) {
-        if (DEBUG_ADD_REMOVE) Slog.v(TAG, "notifyAppResumed: wasStopped=" + wasStopped + " " + this);
+    void notifyAppResumed(boolean wasStopped, boolean allowSavedSurface) {
+        if (DEBUG_ADD_REMOVE) Slog.v(TAG, "notifyAppResumed: wasStopped=" + wasStopped
+                + " allowSavedSurface=" + allowSavedSurface + " " + this);
         mAppStopped = false;
         if (!wasStopped) {
             destroySurfaces(true /*cleanupOnResume*/);
         }
+        if (!allowSavedSurface) {
+            destroySavedSurfaces();
+        }
     }
 
     /**

services/core/java/com/android/server/wm/WindowManagerService.java

@@ -4479,7 +4479,7 @@ public class WindowManagerService extends IWindowManager.Stub
     }
 
     @Override
-    public void notifyAppResumed(IBinder token, boolean wasStopped) {
+    public void notifyAppResumed(IBinder token, boolean wasStopped, boolean allowSavedSurface) {
         if (!checkCallingPermission(android.Manifest.permission.MANAGE_APP_TOKENS,
                 "notifyAppResumed()")) {
             throw new SecurityException("Requires MANAGE_APP_TOKENS permission");
@@ -4492,7 +4492,7 @@ public class WindowManagerService extends IWindowManager.Stub
                 Slog.w(TAG_WM, "Attempted to notify resumed of non-existing app token: " + token);
                 return;
             }
-            wtoken.notifyAppResumed(wasStopped);
+            wtoken.notifyAppResumed(wasStopped, allowSavedSurface);
         }
     }
 

tools/layoutlib/bridge/src/android/view/IWindowManagerImpl.java

@@ -351,7 +351,8 @@ public class IWindowManagerImpl implements IWindowManager {
     }
 
     @Override
-    public void notifyAppResumed(IBinder token, boolean wasStopped) throws RemoteException {
+    public void notifyAppResumed(IBinder token, boolean wasStopped, boolean allowSavedSurface)
+            throws RemoteException {
         // TODO Auto-generated method stub
     }