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 
17 package com.android.launcher2;
18 
19 import android.os.Handler;
20 
21 public 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     private boolean mAlarmPending = false;
32 
Alarm()33     public Alarm() {
34         mHandler = new Handler();
35     }
36 
setOnAlarmListener(OnAlarmListener alarmListener)37     public void setOnAlarmListener(OnAlarmListener alarmListener) {
38         mAlarmListener = alarmListener;
39     }
40 
41     // Sets the alarm to go off in a certain number of milliseconds. If the alarm is already set,
42     // it's overwritten and only the new alarm setting is used
setAlarm(long millisecondsInFuture)43     public void setAlarm(long millisecondsInFuture) {
44         long currentTime = System.currentTimeMillis();
45         mAlarmPending = true;
46         mAlarmTriggerTime = currentTime + millisecondsInFuture;
47         if (!mWaitingForCallback) {
48             mHandler.postDelayed(this, mAlarmTriggerTime - currentTime);
49             mWaitingForCallback = true;
50         }
51     }
52 
cancelAlarm()53     public void cancelAlarm() {
54         mAlarmTriggerTime = 0;
55         mAlarmPending = false;
56     }
57 
58     // this is called when our timer runs out
run()59     public void run() {
60         mWaitingForCallback = false;
61         if (mAlarmTriggerTime != 0) {
62             long currentTime = System.currentTimeMillis();
63             if (mAlarmTriggerTime > currentTime) {
64                 // We still need to wait some time to trigger spring loaded mode--
65                 // post a new callback
66                 mHandler.postDelayed(this, Math.max(0, mAlarmTriggerTime - currentTime));
67                 mWaitingForCallback = true;
68             } else {
69                 mAlarmPending = false;
70                 if (mAlarmListener != null) {
71                     mAlarmListener.onAlarm(this);
72                 }
73             }
74         }
75     }
76 
alarmPending()77     public boolean alarmPending() {
78         return mAlarmPending;
79     }
80 }
81 
82 interface OnAlarmListener {
onAlarm(Alarm alarm)83     public void onAlarm(Alarm alarm);
84 }
85