Adding a compatibility implementation for WindowCallbacks

/*

 * Copyright (C) 2018 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 com.android.systemui.shared.system;

import android.graphics.Canvas;

import android.graphics.Rect;

import android.view.DisplayListCanvas;

import android.view.View;

import android.view.ViewRootImpl;

import android.view.WindowCallbacks;

public class WindowCallbacksCompat {

    private final WindowCallbacks mWindowCallbacks = new WindowCallbacks() {

        @Override

        public void onWindowSizeIsChanging(Rect newBounds, boolean fullscreen, Rect systemInsets,

                Rect stableInsets) {

            WindowCallbacksCompat.this.onWindowSizeIsChanging(newBounds, fullscreen, systemInsets,

                    stableInsets);

        }

        @Override

        public void onWindowDragResizeStart(Rect initialBounds, boolean fullscreen,

                Rect systemInsets, Rect stableInsets, int resizeMode) {

            WindowCallbacksCompat.this.onWindowDragResizeStart(initialBounds, fullscreen,

                    systemInsets, stableInsets, resizeMode);

        }

        @Override

        public void onWindowDragResizeEnd() {

            WindowCallbacksCompat.this.onWindowDragResizeEnd();

        }

        @Override

        public boolean onContentDrawn(int offsetX, int offsetY, int sizeX, int sizeY) {

            return WindowCallbacksCompat.this.onContentDrawn(offsetX, offsetY, sizeX, sizeY);

        }

        @Override

        public void onRequestDraw(boolean reportNextDraw) {

            WindowCallbacksCompat.this.onRequestDraw(reportNextDraw);

        }

        @Override

        public void onPostDraw(DisplayListCanvas canvas) {

            WindowCallbacksCompat.this.onPostDraw(canvas);

        }

    };

    public void onWindowSizeIsChanging(Rect newBounds, boolean fullscreen, Rect systemInsets,

            Rect stableInsets) { }

    public void onWindowDragResizeStart(Rect initialBounds, boolean fullscreen, Rect systemInsets,

            Rect stableInsets, int resizeMode) { }

    public void onWindowDragResizeEnd() { }

    public boolean onContentDrawn(int offsetX, int offsetY, int sizeX, int sizeY) {

        return false;

    }

    public void onRequestDraw(boolean reportNextDraw) { }

    public void onPostDraw(Canvas canvas) { }

    public final boolean addToView(View view) {

        ViewRootImpl root = view.getViewRootImpl();

        if (root != null) {

            root.addWindowCallbacks(mWindowCallbacks);

            root.requestInvalidateRootRenderNode();

            return true;

        }

        return false;

    }

    public final void removeFromView(View view) {

        ViewRootImpl root = view.getViewRootImpl();

        if (root != null) {

            root.removeWindowCallbacks(mWindowCallbacks);

        }

    }

}