Fix activity move between displays

1. ActivityConfigCallback might not have been registered
because DecorView was not yet attached to window and ViewRootImpl
was not available. In this CL the callback is set as soon as a
DecorView is attached to window.
2. When private display was removed from system, its stacks were
moved to bottom in AM but moved to top in WM.
3. When reparenting stack visibility of activities should be updated
before reparenting in WM, because otherwise WM will be resizing
windows that should no longer visible and reporting it to clients.

Bug: 34164473
Test: android.server.cts.ActivityManagerDisplayTests
Test: #testOnMovedToDisplayCallback
Test: #testContentDestroyOnDisplayRemoved
Change-Id: I6ccc27d873d0d60d7650659fb25cbfcaaeb0fd07
diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index af3bf2a..62a4e45 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -18,6 +18,7 @@
 
 import android.metrics.LogMaker;
 import android.graphics.Rect;
+import android.view.ViewRootImpl.ActivityConfigCallback;
 import android.view.autofill.AutofillId;
 import android.view.autofill.AutofillManager;
 import android.view.autofill.AutofillPopupWindow;
@@ -6778,12 +6779,12 @@
             CharSequence title, Activity parent, String id,
             NonConfigurationInstances lastNonConfigurationInstances,
             Configuration config, String referrer, IVoiceInteractor voiceInteractor,
-            Window window) {
+            Window window, ActivityConfigCallback activityConfigCallback) {
         attachBaseContext(context);
 
         mFragments.attachHost(null /*parent*/);
 
-        mWindow = new PhoneWindow(this, window);
+        mWindow = new PhoneWindow(this, window, activityConfigCallback);
         mWindow.setWindowControllerCallback(this);
         mWindow.setCallback(this);
         mWindow.setOnWindowDismissedCallback(this);
diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index 7299d6b..80e8527 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -2748,7 +2748,7 @@
                 activity.attach(appContext, this, getInstrumentation(), r.token,
                         r.ident, app, r.intent, r.activityInfo, title, r.parent,
                         r.embeddedID, r.lastNonConfigurationInstances, config,
-                        r.referrer, r.voiceInteractor, window);
+                        r.referrer, r.voiceInteractor, window, r.configCallback);
 
                 if (customIntent != null) {
                     activity.mIntent = customIntent;
@@ -3774,12 +3774,6 @@
                 if (r.activity.mVisibleFromClient) {
                     r.activity.makeVisible();
                 }
-                final ViewRootImpl viewRoot = r.activity.mDecor.getViewRootImpl();
-                if (viewRoot != null) {
-                    // TODO: Figure out the best place to set the callback.
-                    // This looks like a place where decor view is already initialized.
-                    viewRoot.setActivityConfigCallback(r.configCallback);
-                }
             }
 
             if (!r.onlyLocalRequest) {
@@ -5147,13 +5141,8 @@
             if (DEBUG_CONFIGURATION) Slog.w(TAG, "Not found target activity to report to: " + r);
             return;
         }
-        final boolean movedToDifferentDisplay = displayId != INVALID_DISPLAY;
-        if (movedToDifferentDisplay) {
-            if (r.activity.getDisplay().getDisplayId() == displayId) {
-                throw new IllegalArgumentException("Activity is already on the target display: "
-                        + displayId);
-            }
-        }
+        final boolean movedToDifferentDisplay = displayId != INVALID_DISPLAY
+                && displayId != r.activity.getDisplay().getDisplayId();
 
         // Perform updates.
         r.overrideConfig = data.overrideConfig;
diff --git a/core/java/android/app/Instrumentation.java b/core/java/android/app/Instrumentation.java
index f9a3ea7..d546f27 100644
--- a/core/java/android/app/Instrumentation.java
+++ b/core/java/android/app/Instrumentation.java
@@ -1146,10 +1146,11 @@
             IllegalAccessException {
         Activity activity = (Activity)clazz.newInstance();
         ActivityThread aThread = null;
-        activity.attach(context, aThread, this, token, 0, application, intent,
+        activity.attach(context, aThread, this, token, 0 /* ident */, application, intent,
                 info, title, parent, id,
                 (Activity.NonConfigurationInstances)lastNonConfigurationInstance,
-                new Configuration(), null, null, null);
+                new Configuration(), null /* referrer */, null /* voiceInteractor */,
+                null /* window */, null /* activityConfigCallback */);
         return activity;
     }
 
diff --git a/core/java/com/android/internal/policy/DecorView.java b/core/java/com/android/internal/policy/DecorView.java
index a8e16c9..f1feca3 100644
--- a/core/java/com/android/internal/policy/DecorView.java
+++ b/core/java/com/android/internal/policy/DecorView.java
@@ -1498,6 +1498,7 @@
             // renderer about it.
             mBackdropFrameRenderer.onConfigurationChange();
         }
+        mWindow.onViewRootImplSet(getViewRootImpl());
     }
 
     @Override
diff --git a/core/java/com/android/internal/policy/PhoneWindow.java b/core/java/com/android/internal/policy/PhoneWindow.java
index 6c9280a..7b966de 100644
--- a/core/java/com/android/internal/policy/PhoneWindow.java
+++ b/core/java/com/android/internal/policy/PhoneWindow.java
@@ -47,6 +47,7 @@
 import android.view.ViewManager;
 import android.view.ViewParent;
 import android.view.ViewRootImpl;
+import android.view.ViewRootImpl.ActivityConfigCallback;
 import android.view.Window;
 import android.view.WindowManager;
 import com.android.internal.R;
@@ -287,6 +288,9 @@
 
     private boolean mUseDecorContext = false;
 
+    /** @see ViewRootImpl#mActivityConfigCallback */
+    private ActivityConfigCallback mActivityConfigCallback;
+
     static class WindowManagerHolder {
         static final IWindowManager sWindowManager = IWindowManager.Stub.asInterface(
                 ServiceManager.getService("window"));
@@ -302,7 +306,8 @@
     /**
      * Constructor for main window of an activity.
      */
-    public PhoneWindow(Context context, Window preservedWindow) {
+    public PhoneWindow(Context context, Window preservedWindow,
+            ActivityConfigCallback activityConfigCallback) {
         this(context);
         // Only main activity windows use decor context, all the other windows depend on whatever
         // context that was given to them.
@@ -323,6 +328,7 @@
                 DEVELOPMENT_FORCE_RESIZABLE_ACTIVITIES, 0) != 0;
         mSupportsPictureInPicture = forceResizable || context.getPackageManager().hasSystemFeature(
                 PackageManager.FEATURE_PICTURE_IN_PICTURE);
+        mActivityConfigCallback = activityConfigCallback;
     }
 
     @Override
@@ -2060,6 +2066,11 @@
         return mDecor;
     }
 
+    /** Notify when decor view is attached to window and {@link ViewRootImpl} is available. */
+    void onViewRootImplSet(ViewRootImpl viewRoot) {
+        viewRoot.setActivityConfigCallback(mActivityConfigCallback);
+    }
+
     static private final String FOCUSED_ID_TAG = "android:focusedViewId";
     static private final String VIEWS_TAG = "android:views";
     static private final String PANELS_TAG = "android:Panels";
diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 51011b5..78887c6 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -489,10 +489,14 @@
     void reparent(ActivityStackSupervisor.ActivityDisplay activityDisplay, boolean onTop) {
         removeFromDisplay();
         mTmpRect2.setEmpty();
-        mWindowContainerController.reparent(activityDisplay.mDisplayId, mTmpRect2);
         postAddToDisplay(activityDisplay, mTmpRect2.isEmpty() ? null : mTmpRect2, onTop);
         adjustFocusToNextFocusableStackLocked("reparent", true /* allowFocusSelf */);
         mStackSupervisor.resumeFocusedStackTopActivityLocked();
+        // Update visibility of activities before notifying WM. This way it won't try to resize
+        // windows that are no longer visible.
+        mStackSupervisor.ensureActivitiesVisibleLocked(null /* starting */, 0 /* configChanges */,
+                !PRESERVE_WINDOWS);
+        mWindowContainerController.reparent(activityDisplay.mDisplayId, mTmpRect2, onTop);
     }
 
     /**
diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index c9bb9e5..68e25c3 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -2775,9 +2775,6 @@
             throw new IllegalArgumentException("moveStackToDisplayLocked: Unknown stackId="
                     + stackId);
         }
-
-        ensureActivitiesVisibleLocked(null /* starting */, 0 /* configChanges */,
-                !PRESERVE_WINDOWS);
         // TODO(multi-display): resize stacks properly if moved from split-screen.
     }
 
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 21be742..23058bd 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -1662,7 +1662,7 @@
         return stack;
     }
 
-    void moveStackToDisplay(TaskStack stack) {
+    void moveStackToDisplay(TaskStack stack, boolean onTop) {
         final DisplayContent prevDc = stack.getDisplayContent();
         if (prevDc == null) {
             throw new IllegalStateException("Trying to move stackId=" + stack.mStackId
@@ -1674,7 +1674,7 @@
         }
 
         prevDc.mTaskStackContainers.removeStackFromDisplay(stack);
-        mTaskStackContainers.addStackToDisplay(stack, true /* onTop */);
+        mTaskStackContainers.addStackToDisplay(stack, onTop);
     }
 
     @Override
diff --git a/services/core/java/com/android/server/wm/StackWindowController.java b/services/core/java/com/android/server/wm/StackWindowController.java
index 5d0384e..bf024cf 100644
--- a/services/core/java/com/android/server/wm/StackWindowController.java
+++ b/services/core/java/com/android/server/wm/StackWindowController.java
@@ -100,7 +100,7 @@
         }
     }
 
-    public void reparent(int displayId, Rect outStackBounds) {
+    public void reparent(int displayId, Rect outStackBounds, boolean onTop) {
         synchronized (mWindowMap) {
             if (mContainer == null) {
                 throw new IllegalArgumentException("Trying to move unknown stackId=" + mStackId
@@ -113,7 +113,7 @@
                         + " to unknown displayId=" + displayId);
             }
 
-            targetDc.moveStackToDisplay(mContainer);
+            targetDc.moveStackToDisplay(mContainer, onTop);
             getRawBounds(outStackBounds);
         }
     }
diff --git a/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java b/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java
index d7d365e..0270bb9 100644
--- a/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java
+++ b/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java
@@ -181,7 +181,7 @@
         assertEquals(dc, token.getDisplayContent());
 
         // Move stack to first display.
-        sDisplayContent.moveStackToDisplay(stack);
+        sDisplayContent.moveStackToDisplay(stack, true /* onTop */);
         assertEquals(sDisplayContent.getDisplayId(), stack.getDisplayContent().getDisplayId());
         assertEquals(sDisplayContent, stack.getParent().getParent());
         assertEquals(sDisplayContent, stack.getDisplayContent());
diff --git a/services/tests/servicestests/src/com/android/server/wm/StackWindowControllerTests.java b/services/tests/servicestests/src/com/android/server/wm/StackWindowControllerTests.java
index 13098f6..61f7f57 100644
--- a/services/tests/servicestests/src/com/android/server/wm/StackWindowControllerTests.java
+++ b/services/tests/servicestests/src/com/android/server/wm/StackWindowControllerTests.java
@@ -103,7 +103,7 @@
         final TaskStack stack2 = stack2Controller.mContainer;
 
         // Reparent
-        stack1Controller.reparent(dc.getDisplayId(), new Rect());
+        stack1Controller.reparent(dc.getDisplayId(), new Rect(), true /* onTop */);
         assertEquals(dc, stack1.getDisplayContent());
         final int stack1PositionInParent = stack1.getParent().mChildren.indexOf(stack1);
         final int stack2PositionInParent = stack1.getParent().mChildren.indexOf(stack2);