Alarm.java revision d3ef3065ab0941567c45e9aec98783138b623c68 
1/*
2 * Copyright (C) 2010 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.launcher2;
18
19import android.os.Handler;
20
21public class Alarm implements Runnable{
22    // if we reach this time and the alarm hasn't been cancelled, call the listener
23    private long mAlarmTriggerTime;
24
25    // if we've scheduled a call to run() (ie called mHandler.postDelayed), this variable is true.
26    // We use this to avoid having multiple pending callbacks
27    private boolean mWaitingForCallback;
28
29    private Handler mHandler;
30    private OnAlarmListener mAlarmListener;
31
32    public Alarm() {
33        mHandler = new Handler();
34    }
35
36    public void setOnAlarmListener(OnAlarmListener alarmListener) {
37        mAlarmListener = alarmListener;
38    }
39
40    // Sets the alarm to go off in a certain number of milliseconds. If the alarm is already set,
41    // it's overwritten and only the new alarm setting is used
42    public void setAlarm(long millisecondsInFuture) {
43        long currentTime = System.currentTimeMillis();
44        mAlarmTriggerTime = currentTime + millisecondsInFuture;
45        if (!mWaitingForCallback) {
46            mHandler.postDelayed(this, mAlarmTriggerTime - currentTime);
47            mWaitingForCallback = true;
48        }
49    }
50
51    public void cancelAlarm() {
52        mAlarmTriggerTime = 0;
53    }
54
55    // this is called when our timer runs out
56    public void run() {
57        mWaitingForCallback = false;
58        if (mAlarmTriggerTime != 0) {
59            long currentTime = System.currentTimeMillis();
60            if (mAlarmTriggerTime > currentTime) {
61                // We still need to wait some time to trigger spring loaded mode--
62                // post a new callback
63                mHandler.postDelayed(this, Math.max(0, mAlarmTriggerTime - currentTime));
64                mWaitingForCallback = true;
65            } else {
66                if (mAlarmListener != null) {
67                    mAlarmListener.onAlarm(this);
68                }
69            }
70        }
71    }
72}
73
74interface OnAlarmListener {
75    public void onAlarm(Alarm alarm);
76}
77