I'm testing an iPad on iOS 4.3, which by default uses 4 finger (up/down) gestures to switch out of apps. This interferes with an on-screen piano keyboard I'm using, however, and want to remove this gesture within the frame of the keyboard. The keyboard does not use the gesture, but it regularly disrupts input (for example, when there is multi-touch input).
One way to detect this is you will get 4 touchesCancelled at once in a single
(NSSet *)touches event if the person accidentally did the 4 finger swipe, and 5 touchesCancelled if the person did the 5 finger grab.
At that point you can display a dialog box in your app, telling the user how to turn off the multitasking gestures, once he switches back to the app.
This is currently impossible to do programmatically. The most complete thread on it is here:
and the answer, if it were true, would probably be here (it's not):
The other way to go would be at least to inform the user that they have the setting "wrong." Can you detect it? It seems you cannot:
iOS Multitasking gestures: Is there any way to check if the user has them turned on or not?
I believe you go to settings> general> Multitasking gestures and turn them off.