Handle config/display changes for WindowContext

Introduce IWindowToken to report config/display changes from
server side. When config change callback is received,
it will update the resources associated with the window token.

Test: WindowContextTests
Bug: 128338354
Bug: 146820733

Change-Id: I871bd78a21dbde1286786e65c340b6259b873660

1 files changed, 76 insertions, 0 deletions

diff --git a/core/java/android/app/WindowTokenClient.java b/core/java/android/app/WindowTokenClient.java
new file mode 100644
index 000000000000..ed0179bb9839
--- /dev/null
+++ b/core/java/android/app/WindowTokenClient.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.app;
+
+import android.annotation.NonNull;
+import android.content.Context;
+import android.content.res.Configuration;
+import android.os.Bundle;
+import android.os.IBinder;
+
+/**
+ * Client implementation of {@link IWindowToken}. It can receive configuration change callbacks from
+ * server when window token config is updated or when it is moved between displays, and update the
+ * resources associated with this token on the client side. This will make sure that
+ * {@link WindowContext} instances will have updated resources and configuration.
+ * @hide
+ */
+public class WindowTokenClient extends IWindowToken.Stub {
+    /**
+     * Attached {@link Context} for this window token to update configuration and resources.
+     * Initialized by {@link #attachContext(Context)}.
+     */
+    private Context mContext = null;
+
+    private final ResourcesManager mResourcesManager = ResourcesManager.getInstance();
+
+    /**
+     * Attaches {@code context} to this {@link WindowTokenClient}. Each {@link WindowTokenClient}
+     * can only attach one {@link Context}.
+     * <p>This method must be called before invoking
+     * {@link android.view.IWindowManager#addWindowTokenWithOptions(IBinder, int, int, Bundle,
+     * String)}.<p/>
+     *
+     * @param context context to be attached
+     * @throws IllegalStateException if attached context has already existed.
+     */
+    void attachContext(@NonNull Context context) {
+        if (mContext != null) {
+            throw new IllegalStateException("Context is already attached.");
+        }
+        mContext = context;
+        ContextImpl impl = ContextImpl.getImpl(mContext);
+        impl.setResources(impl.createWindowContextResources());
+    }
+
+    @Override
+    public void onConfigurationChanged(Configuration newConfig, int newDisplayId) {
+        final int currentDisplayId = mContext.getDisplayId();
+        final boolean displayChanged = newDisplayId != currentDisplayId;
+        final Configuration config = new Configuration(mContext.getResources()
+                .getConfiguration());
+        final boolean configChanged = config.isOtherSeqNewer(newConfig)
+                && config.updateFrom(newConfig) != 0;
+        if (displayChanged || configChanged) {
+            // TODO(ag/9789103): update resource manager logic to track non-activity tokens
+            mResourcesManager.updateResourcesForActivity(asBinder(), config, newDisplayId,
+                    displayChanged);
+        }
+        if (displayChanged) {
+            mContext.updateDisplay(newDisplayId);
+        }
+    }
+}