I’m looking at making an application which doesn’t yield to the home button when the button is pressed. Logically speaking I doubt this behavior is possible for security reasons (to prevent phones being hijacked). It is however an important feature for my app which is being written to help my mentally handicapped uncle use his phone.
My question at a high level is can I prevent him closing the application and returning to the core android home page/switching applications? Or is it the case that I would have to modify the android OS itself and create my own custom flavour and then jail-break/flash the phone with it?
You can’t really do this without modifying the firmware. You can get close though by writing and installing your own launcher app that automatically starts your ‘modal’ app. So when you press home, instead of the the installed app drawer, you will land right back in your app. Of course this can be disabled, and might not be too smooth but should work.