Question

I have an application with notifications that open a certain activity if I click them. I want that, if I click the notification and the activity is already opened, it’s not started again, but just brought to front.

I thought I could do it with the flag FLAG_ACTIVITY_BROUGHT_TO_FRONT or FLAG_ACTIVITY_REORDER_TO_FRONT, but it keeps opening it again so I have the activity twice.

This is my code:

event_notification = new Notification(R.drawable.icon,
            mContext.getString(R.string.event_notif_message), System.currentTimeMillis()); 
Intent notificationIntent = new Intent(mContext, EventListActivity.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT);
sendNotification(event_notification, notificationIntent, mContext.getString(R.string.event_notif_title),
                body, Utils.PA_NOTIFICATIONS_ID);

Can I manage it with flags or should I store a variable in SharedPreferences to check if it’s opened or not?

Thanks!

Answer 1

You need to set the launchMode attribute of the Activity you are starting to singleTop. This will cause incoming Intents to be delivered to the existing instance rather than starting a new instance when that Activity is already at the top of the task’s stack.

This is done in the manifest by adding android:launchMode="singleTop" to the <activity> element. To access the latest Intent (if you are interested in any data that may have passed in with it), override onNewIntent() in your Activity.