Android : Capture Screenshot Image of Activity A from Activity B

A project has 2 activities: activity A and activity B. Activity A belongs to the project. Activity B belongs to a "library" inside the project. Activity A launches activity B (activity A -> activity B) Problem: I need to capture screenshot image of Activity A. Action button to capture screenshot is in Activity B Requirement: Get into activity A and capture its screenshot (Root views drawing cache) from activity B. Don't use "startActivityForResult" because activity A may have performed some action & its UI could have changed since then. I hope I've been able to explain this well. I'm attaching a simple screenshot to give an idea. In case of any doubts, pls feel free to ask. PS: Solution to be compatible from Android 4.0 to 6.x For sake of clarity, I've included a simple image indicating the scenario.