1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
5 * except in compliance with the License. You may obtain a copy of the License at
6 *
7 *      http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the
10 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
11 * KIND, either express or implied. See the License for the specific language governing
12 * permissions and limitations under the License.
13 */
14
15package com.android.systemui.statusbar.phone;
16
17import android.content.Context;
18import android.content.res.Configuration;
19import android.graphics.Rect;
20import android.support.annotation.VisibleForTesting;
21import android.util.AttributeSet;
22import android.util.Log;
23import android.util.Pair;
24import android.view.MotionEvent;
25import android.view.View;
26import android.view.ViewGroup;
27import android.widget.FrameLayout;
28
29import com.android.systemui.R;
30
31import java.util.ArrayList;
32import java.util.Comparator;
33
34/**
35 * Redirects touches that aren't handled by any child view to the nearest
36 * clickable child. Only takes effect on <sw600dp.
37 */
38public class NearestTouchFrame extends FrameLayout {
39
40    private final ArrayList<View> mClickableChildren = new ArrayList<>();
41    private final boolean mIsActive;
42    private final int[] mTmpInt = new int[2];
43    private final int[] mOffset = new int[2];
44    private View mTouchingChild;
45
46    public NearestTouchFrame(Context context, AttributeSet attrs) {
47        this(context, attrs, context.getResources().getConfiguration());
48    }
49
50    @VisibleForTesting
51    NearestTouchFrame(Context context, AttributeSet attrs, Configuration c) {
52        super(context, attrs);
53        mIsActive = c.smallestScreenWidthDp < 600;
54    }
55
56    @Override
57    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
58        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
59        mClickableChildren.clear();
60        addClickableChildren(this);
61    }
62
63    @Override
64    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
65        super.onLayout(changed, left, top, right, bottom);
66        getLocationInWindow(mOffset);
67    }
68
69    private void addClickableChildren(ViewGroup group) {
70        final int N = group.getChildCount();
71        for (int i = 0; i < N; i++) {
72            View child = group.getChildAt(i);
73            if (child.isClickable()) {
74                mClickableChildren.add(child);
75            } else if (child instanceof ViewGroup) {
76                addClickableChildren((ViewGroup) child);
77            }
78        }
79    }
80
81    @Override
82    public boolean onTouchEvent(MotionEvent event) {
83        if (mIsActive) {
84            if (event.getAction() == MotionEvent.ACTION_DOWN) {
85                mTouchingChild = findNearestChild(event);
86            }
87            if (mTouchingChild != null) {
88                event.offsetLocation(mTouchingChild.getWidth() / 2 - event.getX(),
89                        mTouchingChild.getHeight() / 2 - event.getY());
90                return mTouchingChild.getVisibility() == VISIBLE
91                        && mTouchingChild.dispatchTouchEvent(event);
92            }
93        }
94        return super.onTouchEvent(event);
95    }
96
97    private View findNearestChild(MotionEvent event) {
98        return mClickableChildren
99                .stream()
100                .filter(v -> v.isAttachedToWindow())
101                .map(v -> new Pair<>(distance(v, event), v))
102                .min(Comparator.comparingInt(f -> f.first))
103                .get().second;
104    }
105
106    private int distance(View v, MotionEvent event) {
107        v.getLocationInWindow(mTmpInt);
108        int left = mTmpInt[0] - mOffset[0];
109        int top = mTmpInt[1] - mOffset[1];
110        int right = left + v.getWidth();
111        int bottom = top + v.getHeight();
112
113        int x = Math.min(Math.abs(left - (int) event.getX()),
114                Math.abs((int) event.getX() - right));
115        int y = Math.min(Math.abs(top - (int) event.getY()),
116                Math.abs((int) event.getY() - bottom));
117
118        return Math.max(x, y);
119    }
120}
121