How can I make the application impersonate the Gallery?

Question

Android

Hello, how can I change someone else's application so that it pretends to be Gallery or Image Editor, in general, so that from Explorer when opening images, when there is a choice of applications than to open, this application would also be displayed there? It is a screenshot editor in itself, but it appears in the options only if you send an image or you need to open screenshots from the application itself, but it’s more convenient for me to open from Root Explorer. I guess that I need to add something to the AndroidManifest.xml of the application, but I don’t know what, I tried to enter some lines by analogy with other applications, but there are always errors, but in theory it should not be difficult for those who write applications, can you tell me on what line and what code should be entered?
AndroidManifest.xml posted on gist.github:
https://gist.github.com/Semiazas1989/4698da8ba0b56...
If this is done through the manifest, if not, then tell me where to look?

Answer 1

You are missing 2 more points.
1) You will need to rebuild the apk by signing it with .
2) For the new action.VIEW, you will need to modify
the handleIntent so that it begins to understand it.
And now, roughly speaking, you think that if in Windows files with the pdf extension it is enough to specify to open with Paint, then you can immediately edit it.