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      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 
     33     public Alarm() {
     34         mHandler = new Handler();
     35     }
     36 
     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
     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 
     53     public void cancelAlarm() {
     54         mAlarmTriggerTime = 0;
     55         mAlarmPending = false;
     56     }
     57 
     58     // this is called when our timer runs out
     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 
     77     public boolean alarmPending() {
     78         return mAlarmPending;
     79     }
     80 }
     81 
     82 interface OnAlarmListener {
     83     public void onAlarm(Alarm alarm);
     84 }
     85