Enable to listen to WindowContext's config changes

This CL overrides registerComponentCallbacks for
WindowContext. Users can use below code snippet
to listen to Configuration changes.
```
Context windowContext = context.createWindowContext(
        display, ...);
windowContext.registerComponentCallbacks(
        new ComponentCallbacks() {
            @Override
            public void onConfigurationChanged(
                    Configuration newConfig) {
                    // Do Something
                }
        });
```

Bug: 181134729
Test: atest WindowContextTests
Test: atest ComponentCallbacksControllerTest

Change-Id: Iff46607bae3c942a96b64dcc97708f3a8c33f23a

1 files changed, 21 insertions, 0 deletions

diff --git a/core/java/android/app/WindowContext.java b/core/java/android/app/WindowContext.java
index cbe2995f2467..d44918cf0379 100644
--- a/core/java/android/app/WindowContext.java
+++ b/core/java/android/app/WindowContext.java
@@ -20,8 +20,11 @@ import static android.view.WindowManagerImpl.createWindowContextWindowManager;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.UiContext;
+import android.content.ComponentCallbacks;
+import android.content.ComponentCallbacksController;
 import android.content.Context;
 import android.content.ContextWrapper;
+import android.content.res.Configuration;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.os.RemoteException;
@@ -49,6 +52,8 @@ public class WindowContext extends ContextWrapper {
     private final IWindowManager mWms;
     private final WindowTokenClient mToken;
     private boolean mListenerRegistered;
+    private final ComponentCallbacksController mCallbacksController =
+            new ComponentCallbacksController();
 
     /**
      * Default constructor. Will generate a {@link WindowTokenClient} and attach this context to
@@ -131,8 +136,24 @@ public class WindowContext extends ContextWrapper {
     }
 
     void destroy() {
+        mCallbacksController.clearCallbacks();
         final ContextImpl impl = (ContextImpl) getBaseContext();
         impl.scheduleFinalCleanup(getClass().getName(), "WindowContext");
         Reference.reachabilityFence(this);
     }
+
+    @Override
+    public void registerComponentCallbacks(@NonNull ComponentCallbacks callback) {
+        mCallbacksController.registerCallbacks(callback);
+    }
+
+    @Override
+    public void unregisterComponentCallbacks(@NonNull ComponentCallbacks callback) {
+        mCallbacksController.unregisterCallbacks(callback);
+    }
+
+    /** Dispatch {@link Configuration} to each {@link ComponentCallbacks}. */
+    void dispatchConfigurationChanged(@NonNull Configuration newConfig) {
+        mCallbacksController.dispatchConfigurationChanged(newConfig);
+    }
 }