1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.systemui;
18
19import android.content.Context;
20import android.graphics.Region;
21import android.graphics.Region.Op;
22import android.util.AttributeSet;
23import android.view.View;
24import android.view.ViewTreeObserver;
25import android.view.ViewTreeObserver.InternalInsetsInfo;
26import android.view.ViewTreeObserver.OnComputeInternalInsetsListener;
27import android.widget.FrameLayout;
28
29/**
30 * Frame layout that will intercept the touches of children if they want to
31 */
32public class RegionInterceptingFrameLayout extends FrameLayout {
33    public RegionInterceptingFrameLayout(Context context) {
34        super(context);
35    }
36
37    public RegionInterceptingFrameLayout(Context context, AttributeSet attrs) {
38        super(context, attrs);
39    }
40
41    public RegionInterceptingFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) {
42        super(context, attrs, defStyleAttr);
43    }
44
45    public RegionInterceptingFrameLayout(Context context, AttributeSet attrs, int defStyleAttr,
46            int defStyleRes) {
47        super(context, attrs, defStyleAttr, defStyleRes);
48    }
49
50    @Override
51    protected void onAttachedToWindow() {
52        super.onAttachedToWindow();
53        getViewTreeObserver().addOnComputeInternalInsetsListener(mInsetsListener);
54    }
55
56    @Override
57    protected void onDetachedFromWindow() {
58        super.onDetachedFromWindow();
59        getViewTreeObserver().removeOnComputeInternalInsetsListener(mInsetsListener);
60    }
61
62    private final OnComputeInternalInsetsListener mInsetsListener = internalInsetsInfo -> {
63        internalInsetsInfo.setTouchableInsets(InternalInsetsInfo.TOUCHABLE_INSETS_REGION);
64        internalInsetsInfo.touchableRegion.setEmpty();
65        for (int i = 0; i < getChildCount(); i++) {
66            View child = getChildAt(i);
67            if (!(child instanceof RegionInterceptableView)) {
68                continue;
69            }
70            RegionInterceptableView riv = (RegionInterceptableView) child;
71            if (!riv.shouldInterceptTouch()) {
72                continue;
73            }
74            Region unionRegion = riv.getInterceptRegion();
75            if (unionRegion == null) {
76                continue;
77            }
78
79            internalInsetsInfo.touchableRegion.op(riv.getInterceptRegion(), Op.UNION);
80        }
81    };
82
83    public interface RegionInterceptableView {
84        default public boolean shouldInterceptTouch() {
85            return false;
86        }
87
88        public Region getInterceptRegion();
89    }
90}
91