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 */
16package com.android.messaging.ui.mediapicker;
17
18import android.content.Context;
19import android.os.SystemClock;
20import android.util.AttributeSet;
21import android.widget.Chronometer;
22
23import com.android.messaging.ui.PlaybackStateView;
24
25/**
26 * A pausable Chronometer implementation. The default Chronometer in Android only stops the UI
27 * from updating when you call stop(), but doesn't actually pause it. This implementation adds an
28 * additional timestamp that tracks the timespan for the pause and compensate for that.
29 */
30public class PausableChronometer extends Chronometer implements PlaybackStateView {
31    // Keeps track of how far long the Chronometer has been tracking when it's paused. We'd like
32    // to start from this time the next time it's resumed.
33    private long mTimeWhenPaused = 0;
34
35    public PausableChronometer(final Context context, final AttributeSet attrs) {
36        super(context, attrs);
37    }
38
39    /**
40     * Reset the timer and start counting from zero.
41     */
42    @Override
43    public void restart() {
44        reset();
45        start();
46    }
47
48    /**
49     * Reset the timer to zero, but don't start it.
50     */
51    @Override
52    public void reset() {
53        stop();
54        setBase(SystemClock.elapsedRealtime());
55        mTimeWhenPaused = 0;
56    }
57
58    /**
59     * Resume the timer after a previous pause.
60     */
61    @Override
62    public void resume() {
63        setBase(SystemClock.elapsedRealtime() - mTimeWhenPaused);
64        start();
65    }
66
67    /**
68     * Pause the timer.
69     */
70    @Override
71    public void pause() {
72        stop();
73        mTimeWhenPaused = SystemClock.elapsedRealtime() - getBase();
74    }
75}
76