I'm making an app that uses an Alarm service. I'm still learning how it works but one thing is very unclear and explained nowhere.
Say you create an Alarm when you launch your app. The alarm is saved somewhere because it needs to trigger even when your app is not running, right?
If so, how can I get this alarm when relaunching my app, so I don't create a new one everytime and have an infinity of alarms stored somewhere?
If not, how does it work? I was thinking about using a database or a json file but I have a feeling it's not necessary.
In my MainActivity class, I have this code to check if the alarm exists already (this code is obviously wrong)...
AlarmReceiver alarm;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b = (Button) findViewById(R.id.button);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(alarm != null){
alarm.cancel();
}
alarm = new AlarmReceiver(MainActivity.this);
}
});
}
I have set a BroadcastReceiver for when the device is rebooted (as explained in the android tutorial)
public class SampleBootReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED")) {
new AlarmReceiver(context);
}
}
}
This is the AlarmReceiver class itself:
public class AlarmReceiver {
private AlarmManager alarmMgr;
private PendingIntent alarmIntent;
public AlarmReceiver(Context context){
alarmMgr = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, AlarmBroadcastReceiver.class);
alarmIntent = PendingIntent.getBroadcast(context, 0, intent, 0);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, 17);
calendar.set(Calendar.MINUTE, 30);
alarmMgr.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
1000 * 60 * 20, alarmIntent);
ComponentName receiver = new ComponentName(context, SampleBootReceiver.class);
PackageManager pm = context.getPackageManager();
pm.setComponentEnabledSetting(receiver,
PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
PackageManager.DONT_KILL_APP);
}
public void cancel(){
alarmMgr.cancel(alarmIntent);
}
}
And the AlarmBroadcastReceiver that simply launches a notification (which works):
public class AlarmBroadcastReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
new NotificationMessage(context);
}
}
The alarm is saved somewhere because it needs to trigger even when your app is not running, right?
Correct.
how can I get this alarm when relaunching my app
You don't. It's a write-only API.
so I don't create a new one everytime and have an infinity of alarms stored somewhere?
Only create an alarm when it is needed, not on every run of your app.
Beyond that, use an equivalent PendingIntent to an existing alarm when calling the AlarmManager methods to replace that alarm (or using cancel() to cancel the alarm).
I was thinking about using a database or a json file but I have a feeling it's not necessary.
You need enough information in persistent storage to know what to do when the alarm goes off. You also need enough information in persistent storage to know what alarms are needed, to handle reboots, when you have to reschedule your previously-scheduled alarms.
Related
I wrote an application which is able to set alarms based on some specif times. These specific times change day by day. For example, sunrise time changes every day. So, I defined a main activity which is responsible to call setExact() method every night at 11:55 p.m and then it has to set tomorrow's alarms based on the specific times for tomorrow. The issue is, it does not work! When I set the alarm, it just works for one time, and it is not going to be set for the second time. I really need help. Thank you :)
public class MainPage extends AppCompatActivity {
private Calendar calendar = new GregorianCalendar();
protected GoogleApiClient client;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setMainAlarm();
}
private void setMainAlarm() {
AlarmManager alarmMgr = (AlarmManager)this.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(".mainAlarmReciever");
PendingIntent alarmIntent = PendingIntent.getBroadcast(this, 1, intent, PendingIntent.FLAG_UPDATE_CURRENT);
Calendar alertCalendar = Calendar.getInstance();
alertCalendar.set(Calendar.HOUR,23);
alertCalendar.set(Calendar.MINUTE,54);
alertCalendar.set(Calendar.SECOND,59);
if (Build.VERSION.SDK_INT >= 23) {
alarmMgr.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, alertCalendar.getTimeInMillis(), alarmIntent);
}else{
alarmMgr.setExact(AlarmManager.RTC_WAKEUP, alertCalendar.getTimeInMillis(), alarmIntent);
}
}
This is the related receiver class for that:
public class mainAlarmReciever extends WakefulBroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
AlarmSetter.createOrUpdateAllAlarms(context);
this.completeWakefulIntent(intent);
}
The issue is you do not set the mainAlarm for tomorrow on your mainAlarmReciever.
Imagine that your mainAlarmReciever->onRecieve run at 11:54:59 P.M tonight. And it does whatever tasks you want to do. You should also set the mainAlarm for Tomorrow at 11:54:59 P.M in your onRecieve function.
Another option is using setRepeating (as CommonsWare mentioned it is not exact after API 19+).
I create an alarm to retrieve location every 30 seconds, as follows:
public class AlarmReceiver extends BroadcastReceiver {
public static final String LOG_TAG = "AlarmReceiver";
#Override
public void onReceive(Context context, Intent intent) {
Log.i(LOG_TAG, "requesting location tracking.");
// start the service
Intent tracking = new Intent(context, LocationUpdateManager.class);
context.startService(tracking);
}
}
Here is the call from MainActivity to start the location update
private void startTracking(Context context) {
Log.i(LOG_TAG, "startTracking()");
// get a Calendar object with current time
Calendar cal = Calendar.getInstance();
cal.add(Calendar.SECOND, START_DELAY);
Intent intent = new Intent(context, AlarmReceiver.class);
trackingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
alarms.setInexactRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), UPDATE_INTERVAL, trackingIntent);
}
And here is the call to stop the location update:
public void stopTracking() {
Log.i(LOG_TAG, "stopTracking()");
Intent intent = new Intent(getBaseContext(), AlarmReceiver.class);
trackingIntent = PendingIntent.getBroadcast(getBaseContext(), 0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
alarms = (AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
alarms.cancel(trackingIntent);
}
In this application, whenever the app is terminated (by any means) I would like to stop the alarm also (i.e. stop updating location). To this end, I call stopTracking() in onDestroy():
protected void onDestroy() {
Log.i(LOG_TAG, "onDestroy()");
stopTracking();
super.onDestroy();
}
I have tested many times on Samsung Galaxy S4 - 4.4.2: I open the app, put it in background (by pressing home button), then open task manager and clear the app from memory. Several times the alarm stops, but several times the alarm is still alive. Could someone explain for me?
You can use application class for that.Application's class instance will be available until when app isn't closed or killed(not minimised).When app get killed onTerminate of this class will be called.See below code.
public class MyApp extends Application {
#Override
public void onCreate() {
super.onCreate();
}
#Override
public void onTerminate() {
super.onTerminate();
//do your code here.
}
}
don't forget to add this instance to AndroidManifest.xml file.
<application
android:name=".MyApp"
android:allowBackup="true"
android:label="#string/app_name" >
</application>
But as suggested by #waqaslam, you should not rely on this because there is no gaurantee that it will be called in Real device Reference here.
One more and better thing that before user kills app from "recent apps" screen or from task manager , onPause() of running activities will be always called. So you need to save all data or do finalize work in onPause() method.That would be better.Hope it will help.Thanks.
Currently I work on a reminder android app, since it remind people to take the pill , so it is really important for the system not missing the alarm.
I found some tutorial and create the code like this:
setTimer.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
GregorianCalendar date = new GregorianCalendar(2014,5,4,15,4); // Month start at 0 , meaning January is 0
long dateTime = date.getTimeInMillis();
AlarmManager alarmManager = (AlarmManager) ctx.getSystemService(Context.ALARM_SERVICE);
Intent intentAlarm = new Intent(ctx, AlarmReceiver.class);
alarmManager.set(AlarmManager.RTC_WAKEUP, dateTime, PendingIntent.getBroadcast(ctx, 1, intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
}
});
Mainfest
<uses-permission android:name="com.android.alarm.permission.SET_ALARM" />
<receiver android:name=".Listener.AlarmReceiver" />
Receiver
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "Alarm Triggered", Toast.LENGTH_LONG).show();
}
}
The problem is I wonder will the alarm invoke even I haven't open the app. The only case missing the alarm is when the user turn off the device? Thanks
You can start a background service through your app which takes care of setting up alarms and firing them even when your app is not opened or in the foreground. Here's a tutorial on services ----> http://www.vogella.com/tutorials/AndroidServices/article.html
This tutorial come from android-er,
The main activity(AndroidScheduledActivity.java) start a AlarmManager to trigger BroadcastReceiver(MyScheduledReceiver.java) repeatly. In the onReceive() method of MyScheduledReceiver, it start another activity(MyScheduledActivity.java) indirectly. Such that the activity(MyScheduledActivity.java) will be start in scheduled interval.
Now I would use AutoStart to start automatically, but I was not able to write the AutoStartNotifyReceiver .
please can you give me an idea how to manage it ?
Thanks a LOT !
main activity, AndroidScheduledActivity.java :
public class AndroidScheduledActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button buttonStart = (Button)findViewById(R.id.start);
buttonStart.setOnClickListener(new Button.OnClickListener(){
#Override
public void onClick(View arg0) {
Intent myIntent = new Intent(getBaseContext(),
MyScheduledReceiver.class);
PendingIntent pendingIntent
= PendingIntent.getBroadcast(getBaseContext(),
0, myIntent, 0);
AlarmManager alarmManager
= (AlarmManager)getSystemService(ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.add(Calendar.SECOND, 10);
long interval = 60 * 1000; //
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,
calendar.getTimeInMillis(), interval, pendingIntent);
finish();
}});
}
}
Then BroadcastReceiver, MyScheduledReceiver.java
public class MyScheduledReceiver extends BroadcastReceiver {
public void onReceive(Context context, Intent intent) {
Intent scheduledIntent = new Intent(context, MyScheduledActivity.class);
scheduledIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(scheduledIntent);
}
}
and my problem AutoStartNotifyReceiver :
public class AutoStartNotifyReceiver extends BroadcastReceiver {
private final String BOOT_COMPLETED_ACTION = "android.intent.action.BOOT_COMPLETED";
#Override
public void onReceive(Context context, Intent intent) {
if(intent.getAction().equals(BOOT_COMPLETED_ACTION)){
????????????????????
}
}
}
Your AutoStartNotifyReceiver extends BroadcastReceiver class is there because the alarms get cleared when the device resets. So, in the onReceive of this class (where you have the question marks) you need to set the alarm all over again with the same code (without, of course the finish())that you used to do it the first time in the onClick method of AndroidScheduledActivity.
Then, you need to put the following entry in your Manifest to let the system know to launch your AutoStartNotifyReceiver when the system boots up:
<receiver android:name=".AutoStartNotifyReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
</intent-filter>
</receiver>
As well as a permission in the Manifest:
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
Now, this is all assuming you only have one alarm and only set it one way every time. If that is not the case than this gets a bit more complicated. But based on the little info you provided, my solution should do what you want.
Also, since you are a newcomer here just a kindly reminder: when someone provides an adequate answer to a question, the person asking the question (you) accepts the answer by clicking the checkbox next to the answer. This is so the person answering gets credit. Welcome to SO!
thanks, it works. just need to improve my java a little more. I have to add "context" don t know exactly why.
public class AutoStartNotifyReceiver extends BroadcastReceiver {
private final String BOOT_COMPLETED_ACTION = "android.intent.action.BOOT_COMPLETED";
public void onReceive(Context context, Intent intent) {
if(intent.getAction().equals(BOOT_COMPLETED_ACTION)){
Intent myIntent = new Intent(context, MyScheduledReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, myIntent, 0);
AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.add(Calendar.SECOND, 10);
long interval = 60 * 1000;
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), interval, pendingIntent);
}
}
}
I am new to Android. I am trying to develop an Alarm Application, which is actually a speaking clock. I just want the clock to use TextToSpeech API and speak out the greeting stuff and the current time as soon as the alarm time is ticked. The speech part is done. And now I want to implement the Alarm functionality. But Initially I am just trying to display a toast after 10 secs in order to check whether my classes are working properly. And I am not getting the desired response and I don't know why ? Following are the classes
Main Class aClockActivity
public class aClockActivity extends Activity {
/** Called when the activity is first created. */
private PendingIntent mAlarmSender;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1 = (Button)findViewById(R.id.buttonOn);
button1.setOnClickListener(mStartAlarmListener);
Button button2 = (Button)findViewById(R.id.buttonOff);
button2.setOnClickListener(mStopAlarmListener);
}
private OnClickListener mStartAlarmListener = new OnClickListener() {
public void onClick(View v) {
// We want the alarm to go off 30 seconds from now.
//long firstTime = SystemClock.elapsedRealtime();
EditText Ehour = (EditText) findViewById(R.id.hour);
EditText Eminute = (EditText) findViewById(R.id.minute);
CharSequence CharHour = Ehour.getText();
CharSequence CharMinute = Eminute.getText();
int hour = Integer.parseInt(CharHour.toString());
int minute = Integer.parseInt(CharMinute.toString());
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(System.currentTimeMillis());
// calendar.add(Calendar.MINUTE, 1);
cal.add(Calendar.SECOND, 10);
mAlarmSender = PendingIntent.getBroadcast(aClockActivity.this,
0, new Intent(aClockActivity.this, Alarm_Broadcast.class), 0);
// Schedule the alarm!
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP,
cal.getTimeInMillis(), mAlarmSender);
// Tell the user about what we did.
Toast.makeText(aClockActivity.this, "The Alarm is Set",
Toast.LENGTH_LONG).show();
}
};
private OnClickListener mStopAlarmListener = new OnClickListener() {
public void onClick(View v) {
// And cancel the alarm.
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
am.cancel(mAlarmSender);
// Tell the user about what we did.
Toast.makeText(aClockActivity.this, "Setting off the alarm",
Toast.LENGTH_LONG).show();
}
};
Second Class Alarm_Broadcast
public class Alarm_Broadcast extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
Toast.makeText(context, "Alarm worked", Toast.LENGTH_LONG).show();
}
}
Note: Just ignore the Edittext part in the OnClick() method, I'd use it later on.
Apart from the above problem there are few questions that I would like to ask.
1) How can I implement this app so that when the alarm is set, it can actually run as a service in the notification bar where the original AlarmClock runs. So that even if the app is closed its still running to invoke the alarm message at the right time.
2) I cannot show any Dialog box or can use TTS if the AlarmManager invokes a Class that extends either Service or BroadcastReciever.
3) I would appreciate if some one give me the idea to implement this app, I am sure there are many experts who would have gone through the same application.
Regards
Omayr
Here is some sample code i used in an alarm clock app hope it helps.
To set the alarm:
private void setAlarm(){
Context context = getApplicationContext();
AlarmManager mgr = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(context, OnAlarmReceiver.class);
PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0);
myCal = Calendar.getInstance();
myCal.setTimeInMillis(TIME_THE_ALARM_SHOULD_GO_OFF_AS_A_LONG);
mgr.set(AlarmManager.RTC_WAKEUP, myCal.getTimeInMillis(), pi);
Log.i(myTag, "alarm set for " + myCal.getTime().toLocaleString());
Toast.makeText(getApplicationContext(),"Alarm set for " + myCal.getTime().toLocaleString(), Toast.LENGTH_LONG).show();
}
This goes in the onAlarmReceiver class:
public void onReceive(Context context, Intent intent) {
Intent i = new Intent(context, AlarmActivity.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}
this will start AlarmActivity whenever it needs to go off. In your case you'd put the toast and speech into the AlarmActivity.
How can I implement this app so that when the alarm is set, it can actually run as a service in the notification bar where the original AlarmClock runs. So that even if the app is closed its still running to invoke the alarm message at the right time.
Do not do this. Having a service stick around in memory 24x7 to watch a clock is a waste of RAM and will get you attacked by task killers, reducing your app's effectiveness. Please stick with AlarmManager.
I cannot show any Dialog box or can use TTS if the AlarmManager invokes a Class that extends either Service or BroadcastReciever.
Start an activity, perhaps a dialog-themed activity.
Just got the answer, whatever service, receiver, activity and etc you are using, you need to register it in your AndroidManifest.xml. Or else it wont work