1/*
2 * Copyright (C) 2015 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 android.view;
18
19import android.os.Handler;
20
21import com.android.internal.util.GrowingArrayUtils;
22
23/**
24 * Class used to enqueue pending work from Views when no Handler is attached.
25 *
26 * @hide Exposed for test framework only.
27 */
28public class HandlerActionQueue {
29    private HandlerAction[] mActions;
30    private int mCount;
31
32    public void post(Runnable action) {
33        postDelayed(action, 0);
34    }
35
36    public void postDelayed(Runnable action, long delayMillis) {
37        final HandlerAction handlerAction = new HandlerAction(action, delayMillis);
38
39        synchronized (this) {
40            if (mActions == null) {
41                mActions = new HandlerAction[4];
42            }
43            mActions = GrowingArrayUtils.append(mActions, mCount, handlerAction);
44            mCount++;
45        }
46    }
47
48    public void removeCallbacks(Runnable action) {
49        synchronized (this) {
50            final int count = mCount;
51            int j = 0;
52
53            final HandlerAction[] actions = mActions;
54            for (int i = 0; i < count; i++) {
55                if (actions[i].matches(action)) {
56                    // Remove this action by overwriting it within
57                    // this loop or nulling it out later.
58                    continue;
59                }
60
61                if (j != i) {
62                    // At least one previous entry was removed, so
63                    // this one needs to move to the "new" list.
64                    actions[j] = actions[i];
65                }
66
67                j++;
68            }
69
70            // The "new" list only has j entries.
71            mCount = j;
72
73            // Null out any remaining entries.
74            for (; j < count; j++) {
75                actions[j] = null;
76            }
77        }
78    }
79
80    public void executeActions(Handler handler) {
81        synchronized (this) {
82            final HandlerAction[] actions = mActions;
83            for (int i = 0, count = mCount; i < count; i++) {
84                final HandlerAction handlerAction = actions[i];
85                handler.postDelayed(handlerAction.action, handlerAction.delay);
86            }
87
88            mActions = null;
89            mCount = 0;
90        }
91    }
92
93    public int size() {
94        return mCount;
95    }
96
97    public Runnable getRunnable(int index) {
98        if (index >= mCount) {
99            throw new IndexOutOfBoundsException();
100        }
101        return mActions[index].action;
102    }
103
104    public long getDelay(int index) {
105        if (index >= mCount) {
106            throw new IndexOutOfBoundsException();
107        }
108        return mActions[index].delay;
109    }
110
111    private static class HandlerAction {
112        final Runnable action;
113        final long delay;
114
115        public HandlerAction(Runnable action, long delay) {
116            this.action = action;
117            this.delay = delay;
118        }
119
120        public boolean matches(Runnable otherAction) {
121            return otherAction == null && action == null
122                    || action != null && action.equals(otherAction);
123        }
124    }
125}
126