Question

Is it possible to handle touch events in the key UIWindow in the app Delegate or anywhere else?

Any help would be appreciated please.

Answer 1

There is a handy catch-all method in UIWindow called sendEvent: which sees every event near the start of the event-handling pipeline. If you want to do any non-standard additional event handling, this is a good place to put it. Something like this:

- (void)sendEvent:(UIEvent *)event {
  if ([self eventIsNoteworthy:event]) [self extraEventHandling:event];
  [super sendEvent:event];  // Apple says you must always call this!
}

Docs: UIWindow class reference | iOS event delivery docs

This blog post also mentions how to override hitTest:withEvent: to catch some events before they’re bound to the target leaf subview in the view hierarchy. You can also override that method on your UIWindow object if you want.