UIApplicationSupportsIndirectInputEvents

Discussion

If the value of this key is YES:

• When the user clicks an indirect pointing device, UIKit generates a UITouch of type UITouch.TouchType.indirectPointer.

• When pinching or rotating using an indirect touch surface, UIKit drives UIPinchGestureRecognizer and UIRotationGestureRecognizer with an event of type UIEvent.EventType.transform.

• Currently, only certain prepackaged gestures in UIKit, like UIPinchGestureRecognizer and UIRotationGestureRecognizer, are capable of handling this event. Other gestures may be added to this list in future releases.

• Gestures that may have worked previously with the simulated touches no longer work.

• Be careful with certain UIGestureRecognizer APIs when gestures are driven by events of type UIEvent.EventType.scroll or UIEvent.EventType.transform.numberOfTouches returns 0, and location(ofTouch:in:) raises an exception because there are no touches driving these gestures with those events. For the case when exceptions might be raised, use either shouldReceive(_:) or the delegate call of gestureRecognizer(_:shouldReceive:) to determine that gesture recognizers are acting on a non-touch-based event.

If the value of this key is NO:

• When the user clicks an indirect pointing device, UIKit generates a UITouch of type UITouch.TouchType.direct.

• When pinching or rotating using an indirect touch surface, UIKit creates touches a fixed distance apart that simulate the gesture on the indirect touch surface.

• Because these are normal UITouch events, they may incidentally activate other gesture recognizers

If you don’t include this key in your app’s Info.plist:

• In iOS 17 and later, the system defaults to supporting indirect input events, meaning it treats your app the same as if you specify YES.

• In versions of iOS earlier than iOS 17, the system defaults to not supporting indirect input events, meaning it treats your app the same as if you specify NO.