core/java/android/app/WindowTokenClient.java

/*
 * 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);
        }
    }
}