android - Intent - if activity is running, bring it to front, else start a new one (from notification)

Question

My app has notifications, which - obviously - without any flags, start a new activity every time so I get multiple same activities running on top of each other, which is just wrong.

What I want it to do is to bring the activity specified in the notifications pending intent, to the front if it is already running, otherwise start it.

So far, the intent/pending intent for that notification I have is

private static PendingIntent prepareIntent(Context context) {
    Intent intent = new Intent(context, MainActivity.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

    return PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
}

and weirdly, it sometimes works, sometimes it doesn't... I feel like I've already tried every single combination of flags.

Answer 1

You can use this:

<activity 
   android:name=".YourActivity"
   android:launchMode="singleTask"/>

which will work similar to "singleInstance" but it won't have that weird animation.