Go back to previous screen without creating new instance

Question

As explained in image, flow is something like this. So whenever user click on logo button Activity A should be called. As simple solution we can use this method...

Intent intent = new Intent(activity, activityToStart);
startActivity(intent);

But this activity will create a new activity for my app. but I need to call the same instance of the activity as we move forward in flow diagram. from Activity A to B and then again on B can be called easily by callingfinish() but from Activity C or D, how to come back to A.

I am running out of ideas but not getting any fruitful result. Please help me if you have any suggestion or at any place i am going wrong. Thanks in advance.

Answer 1

To Come Back from D to A, use Intent Flags.

Intent intent = new Intent(activity, activityToStart);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
startActivity(intent);

FLAG_ACTIVITY_CLEAR_TOP, will instead of creating new activity, it will invoke the activity on the stack, and will pop all the activities over the activity being invoked.

Answer 2

Instead of Using

Intent intent = new Intent(activity, activityToStart);
startActivity(intent);

Use

Intent intent = new Intent(activity, activityToStart);
startActivityforResult(intent,1234);

This will make Sure that The Activity A is not Killed and when You finish Your Activity C,Activity A will get Resumed.

Note :- Whenever You create A new Activity,without finishing(Exiting) the Host Activity,The Host Activity is Saved On the Stack in LIFO order

LIFO:- Last In First Out