Develop Reference

startActivity() in broadcast receiver bag(?)

I'm trying to start MainActivity with BluetoothDevice.ACTION_ACL_CONNECTED receive just like in some stack overflow answers
public class BTReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Log.d("BT", "Receive");
String action = intent.getAction();
...
switch (action) {
case BluetoothDevice.ACTION_ACL_CONNECTED:
Intent i = new Intent();
i.setClassName("com.opendashcam", "com.opendashcam.MainActivity");
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}
}
}
And like this
Intent intent1 = new Intent(context, MainActivity.class);
intent1.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent1);
But all that I can see it's just these logs (first two say that receive was gotten and activity was started with connection to written MAC)
D/BT: Receive
D/BT: started app with 00:14:41:1E:26:27
I/Timeline: Timeline: Activity_launch_request time:129879532
My Main Activity's onCreate:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("MA", "Started app");
init();
}

Since Android 10, according to Android Developers docs ,Android does not allow launching an activity from the background:
Android 10 (API level 29) and higher place restrictions on when apps can start activities when the app is running in the background. These restrictions help minimize interruptions for the user and keep the user more in control of what's shown on their screen.
As an alternative, you can show notification that will launch the activity if clicked:
In nearly all cases, apps that are in the background should display time-sensitive notifications to provide urgent information to the user instead of directly starting an activity.

Pop up window after the alarm signal - Android

I would like to know - how to show pop up window when AlarmManager will call? I've already created AlarmManager now I need to create something what will show popup window to cancel this Alarm.
My code:
public void setAlarm(long timeInMillis){
if(Build.VERSION.SDK_INT >= 23){
mCalendar.set(
mCalendar.get(Calendar.MONTH),
mCalendar.get(Calendar.YEAR),
mCalendar.get(Calendar.DAY_OF_YEAR),
mCalendar.get(Calendar.HOUR_OF_DAY),
mCalendar.get(Calendar.MINUTE)
);
}
final AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(this, MyAlarm.class);
intent.setData(currentUri);
final PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
alarmManager.setExact(AlarmManager.RTC, timeInMillis, pendingIntent);
}
and
public class MyAlarm extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
MediaPlayer mediaPlayer = MediaPlayer.create(context, Settings.System.DEFAULT_RINGTONE_URI);
mediaPlayer.start();
}
}

onReceive(context, intent) {
/*show the dialog in this method. set the onclick so it can dismiss the alarm,
get the value for the alarm from the bundle. I may be wrong about this
but i think alarmManager has a cancel(PendingIntent operation) method that u can
just send in the intent and your done.
Call a stopMedia(context) method after the cancel in order to stop the media
that is playing
*/
showDialog(context, intent)
//Extract the play media code to a method for readability
playMedia(context)
}
That should solve your problem
Before the code was posted:
We can either use the pending intent and have an activity that handles the pending intent. or use the handler to execute the code.
In either case, create a dialog fragment and then use the appropriate context to show it. setOnClickListener { alarmManager.cancel } for the dialog fragment button.
A little more explanation may be required depending on how the alarm manager is setup

Local Notifications in an Android Library

I'm writing here because I'm facing a probleme that I could not resolve even after many researches and tries.
I'm currently developing an Android Library which consists only of java classes and fragment. The problem is I need to send Local Notifications to the user, and clicking on the notifications should send the user back to the activity where he was. At this point, my library sends the notifications just fine. But the click on the notification doesn't have any action.
In my notification reciver class (which extends the BroadcastReceiver class), when the notification appears, I create a Pending Intent but I don't know what I can give as parameters to send the user to the activity. I tried using intent filters but it give me no results
So how can I have the notification sending back the user to the application ? The best would be if I was able to have the notification sending back the user to the activity where the notification is created (but it's a fragment so...)
In an usual app, I would've an intent sending back the user to an activity class but my library needs to have only fragments.
Maybe there is no problem and the solution is easy since I'm new to notifications
If someone here have an idea thanks for helping me ! :D
And if my problem isn't clear (Because of my bad english as an example) don't hesitate to ask me to add informations ^^
**Edit from 29 April : **
I managed to achieve it by giving to my broadcast pending intent the canonical name of my class using :
mContext.getClass().getCanonicalName();
Once in my broadcast receiver class I just get the class from the name of the sending class :
Class<?> activityClass = null;
try {
activityClass = Class.forName(stringSourceClass);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}

Check out below code...
public BroadcastReceiver batteryReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
try {
String title = context.getString(R.string.app_name);
Intent intent1 = new Intent(context, YourActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(),1,intent1,PendingIntent.FLAG_UPDATE_CURRENT);
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context)
.setSmallIcon(R.drawable.ic_launcher)
.setContentTitle(title)
.setContentText("Hello")
.setAutoCancel(false)
.setContentIntent(pendingIntent);
NotificationManager notificationManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(1, notificationBuilder.build());
} catch (Exception e) {
}
}
};

check the Building a notification page:
Intent resultIntent = new Intent(this, ResultActivity.class);
...
// Because clicking the notification opens a new ("special") activity, there's
// no need to create an artificial back stack.
PendingIntent resultPendingIntent =
PendingIntent.getActivity(
this,
0,
resultIntent,
PendingIntent.FLAG_UPDATE_CURRENT
);
just put your activity in resultIntent

how can I have the notification sending back the user to the
application ?
That's pretty simple:
1. While creating intent for pending intent call addAction ("action_name") method;
2. In activity you want to call (in manifest file) inside intent-filter tag add <action android:name="action_name>.
Now when your notification try to launch activity it would send intent message to system, which would search activity with proper action and launch it.
P.S. action name must be unique for every application

android stopwatch/timer app - switching back to app when time runs out

I'm developing an app, as mentioned in title. I need somehow to manage that application will be running/counting time even when user starts/switches to another application. Well, as I learned from another discussion at stackoverflow.com, there is no need to create service that works in background and pointlessly burden processor with counting time when app is not active.
Everything what is needed to be done is to store current time when user switch to another app, compare it to time when he switches back and update the UI according to difference between these times. That's for stopwatch mode. When in timer mode, I need to automatically switch back to application according to time, that is app's UI showing when going o background. What could be the best solution suitable for this and can you give me please some simple examples for this?

Use AlarmManager for that. AlarmManager allows you to schedule tasks and get notified when they are fired.

So use AlarmManager
public class MainActivity extends Activity
{
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//call function where you want
timeout();
}
public void timeout()
{ //time in milliseconds 1 minute
Long time = new GregorianCalendar().getTimeInMillis()+60*1000; //i.e.60*1000=1minute
// create an Intent and set the class which will execute when Alarm triggers, here we have
Intent intentAlarm = new Intent(this, AlarmReciever.class);
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC_WAKEUP,time, PendingIntent.getBroadcast(this,1, intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
}
}
Here is broadcast class:
public class AlarmReciever extends BroadcastReceiver
{
#Override
public void onReceive(Context context, Intent intent)
{
// show dialog or what you want
}
}
Don't forgot to edit AndroidMainfest:
//permission
<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
//our receiver
<receiver android:name=".AlarmReciever"/>

Passing Activity Instance to IntentService

Im am trying to pass an instance of my activity to an intent service. The reason for this is the intent service does a lot of background server communication and if there is an network error or the server returns an error I want to display a pop up message.
When i create the service i use this
Intent service = new Intent(this, SyncService.class);
Bundle b2 = new Bundle();
b2.putParcelable(StringsConfig.OBJECT_DELIVERABLES, objects);
service.putExtras(b2);
startService(service);
Is there a way to pass an instance of an Activity over to it. I also have a method inside the SyncService class that accept an Activity but i dont know how to create an instance of the sync service class, pass the activity over via the method, and then start the sync service.
Any help is appreciated.

Its not a great idea to pass an Activity instance to an Intent Service. If your long running Background Service needs to show a dialog message, you are much better off modelling it as an Intent.
Just do:
Intent dialogIntent = new Intent(getApplicationContext(), YourDialogActivity.class);
dialogIntent.putStringExtra(Constants.TITLE, "Your Dialog Title");
dialogIntent.putIntExtra(Constants.MESSAGE, R.string.yourErrorMessageId);
startActivity(dialogIntent);
That way, the service contract is a lot cleaner.

The recommended way for an IntentService to communicate to an activity is via BroadcastReceiver. Take a look at this example:
In the activity that you want your IntentService to communicate with, create a BroadcastReceiver that listens for a specific intent action (a String). Here my example is called batchProcessReceiver, and listens for the BATCH_PROCESS_RECEIVER action. BATCH_PROCESS_RECEIVER can be a public static constant in your Activity.
private BroadcastReceiver batchProcessReceiver = new BroadcastReceiver() {
#Override public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(BATCH_PROCESS_RECEIVER)) {
// do what you need to do here
}
}
};
In your activity's onResume:
registerReceiver(batchProcessReceiver, new IntentFilter(BATCH_PROCESS_RECEIVER));
onPause:
unregisterReceiver(batchProcessReceiver);
Then at a point in your IntentService, you can do
sendBroadcast(new Intent(MyActivity.BATCH_PROCESS_RECEIVER));
to trigger the action you want to do in your activity.