Is it technically possible to send commands/events to other apps on iOS? Is there something like a system bus on iOS? Specifically, I'm interested in triggering the release button of the camera app, while open/running in order to take a shot. My thought was, maybe it's possible to generate the event that is sent whenever the user presses the -/+ buttons on the headset, for example, which also releases the camera.
UPDATE:
I'm not trying to build my own camera app. What I'm trying to accomplish is to trigger the camera app from a background service/daemon. So assume the iOS built-in camera app is running. Can a background service/daemon send commands/events to another app? Or is there some sort of "magic" system wide event that would trigger the camera?
UPDATE:
I found this question, where the event codes from the remote are read. Is it possible to send those to the system?
Any hint appreciated.