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.launcher3;
18 
19 import android.os.Handler;
20 import android.os.SystemClock;
21 
22 public class Alarm implements Runnable{
23     // if we reach this time and the alarm hasn't been cancelled, call the listener
24     private long mAlarmTriggerTime;
25 
26     // if we've scheduled a call to run() (ie called mHandler.postDelayed), this variable is true.
27     // We use this to avoid having multiple pending callbacks
28     private boolean mWaitingForCallback;
29 
30     private Handler mHandler;
31     private OnAlarmListener mAlarmListener;
32     private boolean mAlarmPending = false;
33 
Alarm()34     public Alarm() {
35         mHandler = new Handler();
36     }
37 
setOnAlarmListener(OnAlarmListener alarmListener)38     public void setOnAlarmListener(OnAlarmListener alarmListener) {
39         mAlarmListener = alarmListener;
40     }
41 
42     // Sets the alarm to go off in a certain number of milliseconds. If the alarm is already set,
43     // it's overwritten and only the new alarm setting is used
setAlarm(long millisecondsInFuture)44     public void setAlarm(long millisecondsInFuture) {
45         long currentTime = SystemClock.uptimeMillis();
46         mAlarmPending = true;
47         long oldTriggerTime = mAlarmTriggerTime;
48         mAlarmTriggerTime = currentTime + millisecondsInFuture;
49 
50         // If the previous alarm was set for a longer duration, cancel it.
51         if (mWaitingForCallback && oldTriggerTime > mAlarmTriggerTime) {
52             mHandler.removeCallbacks(this);
53             mWaitingForCallback = false;
54         }
55         if (!mWaitingForCallback) {
56             mHandler.postDelayed(this, mAlarmTriggerTime - currentTime);
57             mWaitingForCallback = true;
58         }
59     }
60 
cancelAlarm()61     public void cancelAlarm() {
62         mAlarmPending = false;
63     }
64 
65     // this is called when our timer runs out
run()66     public void run() {
67         mWaitingForCallback = false;
68         if (mAlarmPending) {
69             long currentTime = SystemClock.uptimeMillis();
70             if (mAlarmTriggerTime > currentTime) {
71                 // We still need to wait some time to trigger spring loaded mode--
72                 // post a new callback
73                 mHandler.postDelayed(this, Math.max(0, mAlarmTriggerTime - currentTime));
74                 mWaitingForCallback = true;
75             } else {
76                 mAlarmPending = false;
77                 if (mAlarmListener != null) {
78                     mAlarmListener.onAlarm(this);
79                 }
80             }
81         }
82     }
83 
alarmPending()84     public boolean alarmPending() {
85         return mAlarmPending;
86     }
87 }
88