Top-level Android Activities

Question

I'm trying to create a basic app using the AppCompat Drawer, and multiple top-level activities (Not fragments) - I can't quite work out how to manage the backstack - I've tried about a hundred different approaches - but they all require some sort of weird hack to either clear the backstack - or finish the existing activity.

I have 3 activities - A, B & C. A & B are top-level, C is a child of B

I want:

• To start Activity A when the app starts
• To exit the app when I press the back button from A
• To start Activity B from the drawer
• To exit the app when I press the back button from B
• To start Activity C from Activity B
• To go back to Activity B when I press the back button from C
• When I start B from B or A from A or B from C by selecting drawer buttons - I should get the top-level Activity back in it's vanilla state.

I have:

protected void startActivity(Class activity) {
    final Intent intent = new Intent(this, activity);
    intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
    startActivity(intent);
    overridePendingTransition(0, 0);
}

Basically I pass in either ActivityA.class or ActivityB.class - with this approach - pressing back from B takes me to A

Using HO_HISTORY, looks ok - but pressing back from C exits the app

Using REORDER_TO_FRONT doesn't seem to do anything??

Using finish() after startActivity works perfectly - unless you choose A or B twice (in which case you exit the app)

Using FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TASK works perfectly in every manner - except for the super nasty screen flashing as tasks are re-created. And the performance hit...

Help??

Answer 1

Can't you just call finish() right after your starActivity call? (you'd have to remove the SINGLE_TOP flag too -- or you'll run into the behaviour you mentioned when going from B -> B)