How to emulate gestures on android in someone else's application?

Question

Android

You need to emulate gestures in someone else's application from your application + take screenshots. Naturally, root is implied.
How to do it?
Ready-made programs are not of interest, you need something at the API level. In the search for some scattered info, mainly about the fact that INJECT_EVENT permissions require a system certificate. Those. with such permissions, at least the application cannot be uploaded to the store.
There are programs in the store that can do this, you need info on how they do it :) https://play.google.com/store/apps/details?id=com....
I found another way like this: www.pocketmagic .net/2013/01/programmatically-injec...but there is still not enough knowledge to understand how the interception of system events and their substitution occurs there. Some native library is used. Can someone clarify?

Answer 1

If you are satisfied with running scripts from a computer, then you can use monkeyrunner and they emulate clicks and can take screenshots.
developer.android.com/tools/help/monkeyrunner_conc...