Fix problem with starting a translucent activity in onCreate().

Fixes issue #2437252: Starting activity by means of startActivityForResult
causes 5 seconds delay if "android:windowIsTranslucent" is true

The optimization to avoid showing an activity window when a new
activity is being started was a little too aggressive.  Now it
avoids doing this if there is not actually a fullscreen activity
on top to cover it.

Change-Id: I630e37a1f1d3b874b5a25572cbf887cebc2e3e91

core/java/android/app/ActivityManagerNative.java

@@ -227,6 +227,15 @@ public abstract class ActivityManagerNative extends Binder implements IActivityM
             return true;
         }
 
+        case WILL_ACTIVITY_BE_VISIBLE_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            IBinder token = data.readStrongBinder();
+            boolean res = willActivityBeVisible(token);
+            reply.writeNoException();
+            reply.writeInt(res ? 1 : 0);
+            return true;
+        }
+
         case REGISTER_RECEIVER_TRANSACTION:
         {
             data.enforceInterface(IActivityManager.descriptor);
@@ -1360,6 +1369,18 @@ class ActivityManagerProxy implements IActivityManager
         data.recycle();
         reply.recycle();
     }
+    public boolean willActivityBeVisible(IBinder token) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeStrongBinder(token);
+        mRemote.transact(WILL_ACTIVITY_BE_VISIBLE_TRANSACTION, data, reply, 0);
+        reply.readException();
+        boolean res = reply.readInt() != 0;
+        data.recycle();
+        reply.recycle();
+        return res;
+    }
     public Intent registerReceiver(IApplicationThread caller,
             IIntentReceiver receiver,
             IntentFilter filter, String perm) throws RemoteException

core/java/android/app/ActivityThread.java

@@ -3095,9 +3095,6 @@ public final class ActivityThread {
 
                 r.paused = false;
                 r.stopped = false;
-                if (r.activity.mStartedActivity) {
-                    r.hideForNow = true;
-                }
                 r.state = null;
             } catch (Exception e) {
                 if (!mInstrumentation.onException(r.activity, e)) {
@@ -3132,7 +3129,15 @@ public final class ActivityThread {
             // If the window hasn't yet been added to the window manager,
             // and this guy didn't finish itself or start another activity,
             // then go ahead and add the window.
-            if (r.window == null && !a.mFinished && !a.mStartedActivity) {
+            boolean willBeVisible = !a.mStartedActivity;
+            if (!willBeVisible) {
+                try {
+                    willBeVisible = ActivityManagerNative.getDefault().willActivityBeVisible(
+                            a.getActivityToken());
+                } catch (RemoteException e) {
+                }
+            }
+            if (r.window == null && !a.mFinished && willBeVisible) {
                 r.window = r.activity.getWindow();
                 View decor = r.window.getDecorView();
                 decor.setVisibility(View.INVISIBLE);
@@ -3148,8 +3153,8 @@ public final class ActivityThread {
 
             // If the window has already been added, but during resume
             // we started another activity, then don't yet make the
-            // window visisble.
-            } else if (a.mStartedActivity) {
+            // window visible.
+            } else if (!willBeVisible) {
                 if (localLOGV) Log.v(
                     TAG, "Launch " + r + " mStartedActivity set");
                 r.hideForNow = true;
@@ -3157,7 +3162,7 @@ public final class ActivityThread {
 
             // The window is now visible if it has been added, we are not
             // simply finishing, and we are not starting another activity.
-            if (!r.activity.mFinished && !a.mStartedActivity
+            if (!r.activity.mFinished && willBeVisible
                     && r.activity.mDecor != null && !r.hideForNow) {
                 if (r.newConfig != null) {
                     if (DEBUG_CONFIGURATION) Log.v(TAG, "Resuming activity "

core/java/android/app/IActivityManager.java

@@ -97,6 +97,7 @@ public interface IActivityManager extends IInterface {
     public boolean finishActivity(IBinder token, int code, Intent data)
             throws RemoteException;
     public void finishSubActivity(IBinder token, String resultWho, int requestCode) throws RemoteException;
+    public boolean willActivityBeVisible(IBinder token) throws RemoteException;
     public Intent registerReceiver(IApplicationThread caller,
             IIntentReceiver receiver, IntentFilter filter,
             String requiredPermission) throws RemoteException;
@@ -501,4 +502,5 @@ public interface IActivityManager extends IInterface {
     int KILL_BACKGROUND_PROCESSES_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+102;
     int IS_USER_A_MONKEY_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+103;
     int START_ACTIVITY_AND_WAIT_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+104;
+    int WILL_ACTIVITY_BE_VISIBLE_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+105;
 }

services/java/com/android/server/am/ActivityManagerService.java

@@ -4268,6 +4268,22 @@ public final class ActivityManagerService extends ActivityManagerNative implemen
         }
     }
 
+    public boolean willActivityBeVisible(IBinder token) {
+        synchronized(this) {
+            int i;
+            for (i=mHistory.size()-1; i>=0; i--) {
+                HistoryRecord r = (HistoryRecord)mHistory.get(i);
+                if (r == token) {
+                    return true;
+                }
+                if (r.fullscreen && !r.finishing) {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+    
     public void overridePendingTransition(IBinder token, String packageName,
             int enterAnim, int exitAnim) {
         synchronized(this) {