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.launcher3;
18
19import android.os.Handler;
20import android.os.SystemClock;
21
22public 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
34    public Alarm() {
35        mHandler = new Handler();
36    }
37
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
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
61    public void cancelAlarm() {
62        mAlarmPending = false;
63    }
64
65    // this is called when our timer runs out
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
84    public boolean alarmPending() {
85        return mAlarmPending;
86    }
87}
88