Retain only one copy of an activity on the stack when called from non-activity

Question

How can I make sure I only retain one copy of an activity on the stack when called from non-activity?

When called from an activity I can just add the FLAG_ACTIVITY_REORDER_TO_FRONT flag to the Intent, but how can I do this from e.g. a widget or a notification?

Answer 1

When launching an Activity from a notification, you're required to create a new task by setting the FLAG_ACTIVITY_NEW_TASK flag.

Since you're required to do this, you can restrict that Activity to only having one instance by adding android:launchMode="singleTask" to its manifest entry.