I have written a calculator app. Its main window is a UIView subclass that usually receives user input from the touchscreen, tapping on a virtual keyboard (not the standard pop-up keyboard).
I recently added hardware keyboard support. In order to receive key events, I implemented canBecomeFirstResponder and made it always return YES, and I'm calling becomeFirstResponder whenever the main window becomes active, and resignFirstResponder when it becomes inactive.
This is working fine except for one scenario: when running the app on an iPad, together with another app, using Split View or Slide Over, and the other app has keyboard focus on a text field, my app doesn't receive keyboard events, even when it's the foreground app. I have to go into the other app, and tap somewhere outside a text field, and then return to my app, before my app is getting key events again.
If the user taps on an actual text field in my app, it gets focus just fine, of course, but apparently my UIView calling becomeFirstResponder is not enough to take away the focus from the other app.
Is there a way to steal the focus from another app's text field in this scenario?