Question

I have a common menu on my app with icons. Clicking an icon will start an Activity. Is there a way to know if an activity is already running and prevent it from starting multiple times (or from multiple entries)? Also can I bring an activity that is in onPause state to the front?

Answer 1

Use this:

intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

while starting Activity.

from documentation:

If set in an Intent passed to Context.startActivity(), this flag will
cause the launched activity to be brought to the front of its task’s
history stack if it is already running.