Managing activities in Android and preventing large activity stack

Question

I'm new to Android development and I have an app with various activities. For performance reasons I'd like to properly manage the activities when users are using my app. Here's my problem.

Activity A - starting activity with map

Activity B - user navigates to Activity B (a list view) from Activity A.

The user then selects the map icon to navigate to Activity A again.

So if you can image it, my activity stack is now:

1. Activity A
2. Activity B
3. Activity A

So if I press the back button the device it will take forever as it scrolls through activities.

Is there a way of managing this so the old activity is destroyed and is just re-created upon choosing an activity nav icon. I've read up about onDestroy() and onStop() but I'm a little confused at their implementation.

Apologies for a poorly worded question but I'm unsure of the correct lexicon to ask about activities.

Answer 1

One simple solution is to kill the Activities as soon as they leave the foreground.

You could do that by calling finish() inside onPause().

Answer 2

You could have B finish itself and return to A instead of starting another A. Or, if your stack might be more complicated, like this:

D
C
B
A

D could start A with FLAG_ACTIVITY_CLEAR_TOP, which would cause D, C, and B to be finished, leaving A on top. (That intent flag interacts non-intuitively with a couple other flags, so read the docs.)