How does one overlay widgets like a button on top of Android's default camera interface?

I would prefer to use Android's default camera control - I like all the functionality it provides and whatnot - but I do want to add just one button to let users skip taking the picture.开发者_如何学Python This would be different from the "back" button in that it would move users forward not backwards in the app's process flow.

You can't do anything to an existing app. Also, some manufacturers implement different versions of the camera app, so it is not sure that the UI will be the same on all devices.