Restore config of associated window when clearing fixed rotation

If wallpaper is visible and its target window has fixed rotation
transform, wallpaper token will be associated to share the same
transform. So if the target window cancels the transform, the
associated window, i.e. wallpaper should also be restored to the
original configuration.

Fixes: 153420536
Fixes: 153201558
Test: atest WindowTokenTests#testClearFixedRotationTransform
Change-Id: I75fe8bfadf3b681f2dc33df9c6599a9bbc5769ea

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

@@ -554,13 +554,12 @@ class WindowToken extends WindowContainer<WindowState> {
         // cleared and the configuration is restored from parent.
         if (!changed) {
             clearFixedRotationTransform(null /* applyDisplayRotation */);
-            onConfigurationChanged(getParent().getConfiguration());
         }
     }
 
     /**
-     * Clears the transform and apply display rotation if the action is given. The caller needs to
-     * refresh the configuration of this container after this method call.
+     * Clears the transform and apply display rotation if the action is given. If the display will
+     * not rotate, the transformed containers are restored to their original states.
      */
     void clearFixedRotationTransform(Runnable applyDisplayRotation) {
         final FixedRotationTransformState state = mFixedRotationTransformState;
@@ -574,6 +573,12 @@ class WindowToken extends WindowContainer<WindowState> {
         state.mIsTransforming = false;
         if (applyDisplayRotation != null) {
             applyDisplayRotation.run();
+        } else {
+            // The display will not rotate to the rotation of this container, let's cancel them.
+            for (int i = state.mAssociatedTokens.size() - 1; i >= 0; i--) {
+                state.mAssociatedTokens.get(i).cancelFixedRotationTransform();
+            }
+            cancelFixedRotationTransform();
         }
         // The state is cleared at the end, because it is used to indicate that other windows can
         // use seamless rotation when applying rotation to display.
@@ -583,6 +588,16 @@ class WindowToken extends WindowContainer<WindowState> {
         mFixedRotationTransformState = null;
     }
 
+    /** Restores the changes that applies to this container. */
+    private void cancelFixedRotationTransform() {
+        final WindowContainer<?> parent = getParent();
+        if (parent == null) {
+            // The window may be detached or detaching.
+            return;
+        }
+        onConfigurationChanged(parent.getConfiguration());
+    }
+
     @Override
     void resolveOverrideConfiguration(Configuration newParentConfig) {
         super.resolveOverrideConfiguration(newParentConfig);

services/tests/wmtests/src/com/android/server/wm/WindowTokenTests.java

@@ -29,6 +29,7 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 
+import android.content.res.Configuration;
 import android.os.IBinder;
 import android.platform.test.annotations.Presubmit;
 
@@ -134,6 +135,30 @@ public class WindowTokenTests extends WindowTestsBase {
         assertEquals(0, token.getWindowsCount());
     }
 
+    @Test
+    public void testClearFixedRotationTransform() {
+        final WindowToken appToken = mAppWindow.mToken;
+        final WindowToken wallpaperToken = mWallpaperWindow.mToken;
+        final Configuration config = new Configuration(mDisplayContent.getConfiguration());
+        final int originalRotation = config.windowConfiguration.getRotation();
+        final int targetRotation = (originalRotation + 1) % 4;
+
+        config.windowConfiguration.setRotation(targetRotation);
+        appToken.applyFixedRotationTransform(mDisplayInfo, mDisplayContent.mDisplayFrames, config);
+        wallpaperToken.linkFixedRotationTransform(appToken);
+
+        // The window tokens should apply the rotation by the transformation.
+        assertEquals(targetRotation, appToken.getWindowConfiguration().getRotation());
+        assertEquals(targetRotation, wallpaperToken.getWindowConfiguration().getRotation());
+
+        // The display doesn't rotate, the transformation will be canceled.
+        mAppWindow.mToken.clearFixedRotationTransform(null /* applyDisplayRotation */);
+
+        // The window tokens should restore to the original rotation.
+        assertEquals(originalRotation, appToken.getWindowConfiguration().getRotation());
+        assertEquals(originalRotation, wallpaperToken.getWindowConfiguration().getRotation());
+    }
+
     /**
      * Test that {@link WindowToken} constructor parameters is set with expectation.
      */