programmatically lock user in Android app

Android 4.2.2

For my internship I'm doing a project at a narrowcasting company.

I need to lock the user in the app. Because we work with Android mini PC's in combination with bluetooth keyboards, I need a way to also disable the FN keys on the bluetooth keyboard (home, music, etc).

What I've done so far:

• hidden all of the system bars on the screen


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  disabled the return button (which was the fix for the Esc button on the keyboards)

  
  


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  tried to disable the home button programatically, which didn't help for the keyboard FN (the devices ARE ROOTED)

  
  

I would appreciate your help!