One option is just to use
postDelayed(Runnable r, long milliseconds)
to trigger your runnable update method for whatever you update period is, without using a service. And then update the UI in your update method.
Another option is to use AsyncTask instead of Service, if your intention is to do something in the background. AsyncTask has access to the UI on its onProgressUpdate()
method and you can do your stuff there.
If you have to use a Service, then you have to broadcast from the service to the UI activity and let the UI Activity do the view update:
This in your main activity:
private StatusReceiver mReceiver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
...
mReceiver = new StatusReceiver();
...
}
@Override
protected void onStart() {
// Register the broadcast receiver
IntentFilter filter = new IntentFilter();
filter.addAction(getString(R.string.ACTION_UPDATE_CHRONO));
filter.addCategory(Intent.CATEGORY_DEFAULT);
registerReceiver(mReceiver, filter);
...
}
@Override
protected void onStop() {
...
unregisterReceiver(mReceiver);
...
}
public class StatusReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if( action.equals(getString(R.string.ACTION_UPDATE_CHRONO)) ) {
// Do your UI stuff here
}
}
}
In the service class:
private void broadcast(String status, Exception error) {
Intent broadcastIntent = new Intent((Intent) getText(R.string.ACTION_UPDATE_CHRONO));
broadcastIntent.putExtra("STATUS", status);
broadcastIntent.putExtra("ERROR", error);
sendBroadcast(broadcastIntent);
}
Call this method when you want to communicate some "status" to your main activity, like "Time for update"
or "set chrono to " + x + "milli"
.