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.recents.views.grid;
18
19import android.content.Context;
20import android.graphics.Rect;
21import android.util.AttributeSet;
22import android.view.View;
23
24import android.view.ViewTreeObserver.OnGlobalFocusChangeListener;
25import com.android.systemui.R;
26import com.android.systemui.shared.recents.model.TaskStack;
27import com.android.systemui.recents.views.TaskStackView;
28
29public class TaskViewFocusFrame extends View implements OnGlobalFocusChangeListener {
30
31    private TaskStackView mSv;
32    private TaskGridLayoutAlgorithm mTaskGridLayoutAlgorithm;
33    public TaskViewFocusFrame(Context context) {
34        this(context, null);
35    }
36
37    public TaskViewFocusFrame(Context context, AttributeSet attrs) {
38        this(context, attrs, 0);
39    }
40
41    public TaskViewFocusFrame(Context context, AttributeSet attrs, int defStyleAttr) {
42        this(context, attrs, defStyleAttr, 0);
43    }
44
45    public TaskViewFocusFrame(Context context, AttributeSet attrs, int defStyleAttr,
46        int defStyleRes) {
47        super(context, attrs, defStyleAttr, defStyleRes);
48        setBackground(mContext.getDrawable(
49            R.drawable.recents_grid_task_view_focus_frame_background));
50        setFocusable(false);
51        hide();
52    }
53
54    public TaskViewFocusFrame(Context context, TaskStackView stackView,
55        TaskGridLayoutAlgorithm taskGridLayoutAlgorithm) {
56        this(context);
57        mSv = stackView;
58        mTaskGridLayoutAlgorithm = taskGridLayoutAlgorithm;
59    }
60
61    /**
62     * Measure the width and height of the focus frame according to the current grid task view size.
63     */
64    public void measure() {
65        int thickness = mTaskGridLayoutAlgorithm.getFocusFrameThickness();
66        Rect rect = mTaskGridLayoutAlgorithm.getTaskGridRect();
67        measure(
68            MeasureSpec.makeMeasureSpec(rect.width() + thickness * 2, MeasureSpec.EXACTLY),
69            MeasureSpec.makeMeasureSpec(rect.height() + thickness * 2, MeasureSpec.EXACTLY));
70    }
71
72    /**
73     * Layout the focus frame with its size.
74     */
75    public void layout() {
76        layout(0, 0, getMeasuredWidth(), getMeasuredHeight());
77    }
78
79    /**
80     * Update the current size of grid task view and the focus frame.
81     */
82    public void resize() {
83        if (mSv.useGridLayout()) {
84            mTaskGridLayoutAlgorithm.updateTaskGridRect(mSv.getStack().getTaskCount());
85            measure();
86            requestLayout();
87        }
88    }
89
90    /**
91     * Move the task view focus frame to surround the newly focused view. If it's {@code null} or
92     * it's not an instance of GridTaskView, we hide the focus frame.
93     * @param newFocus The newly focused view.
94     */
95    public void moveGridTaskViewFocus(View newFocus) {
96        if (mSv.useGridLayout()) {
97            // The frame only shows up in the grid layout. It shouldn't show up in the stack
98            // layout including when we're in the split screen.
99            if (newFocus instanceof GridTaskView) {
100                // If the focus goes to a GridTaskView, we show the frame and layout it.
101                int[] location = new int[2];
102                newFocus.getLocationInWindow(location);
103                int thickness = mTaskGridLayoutAlgorithm.getFocusFrameThickness();
104                setTranslationX(location[0] - thickness);
105                setTranslationY(location[1] - thickness);
106                show();
107            } else {
108                // If focus goes to other views, we hide the frame.
109                hide();
110            }
111        }
112    }
113
114    @Override
115    public void onGlobalFocusChanged(View oldFocus, View newFocus) {
116        if (!mSv.useGridLayout()) {
117            return;
118        }
119        if (newFocus == null) {
120            // We're going to touch mode, unset the focus.
121            moveGridTaskViewFocus(null);
122            return;
123        }
124        if (oldFocus == null) {
125            // We're returning from touch mode, set the focus to the previously focused task.
126            final TaskStack stack = mSv.getStack();
127            final int taskCount = stack.getTaskCount();
128            final int k = stack.indexOfTask(mSv.getFocusedTask());
129            final int taskIndexToFocus = k == -1 ? (taskCount - 1) : (k % taskCount);
130            mSv.setFocusedTask(taskIndexToFocus, false, true);
131        }
132    }
133
134    private void show() {
135        setAlpha(1f);
136    }
137
138    private void hide() {
139        setAlpha(0f);
140    }
141}
142