NSEvent and Magic Mouse

Question

How do I distinguish whether the event -(void)scrollWheel:(NSEvent *)event was triggered by a Magic Mouse or a trackpad?

The reason I'm asking this question is because I want to assign a different action to the scrolling event when a trackpad is used because the user can pinch to zoom on the trackpad. On the magic mouse, however, the user can't pinch easily, so I want to use the scrolling function as a substitute for pinching.

I can distinguish between a normal mouse and a Magic Mouse using this line:

if (([event momentumPhase] != NSEventPhaseNone) || [event phase] != NSEventPhaseNone)

However this test is passed for both, trackpad and Magic Mouse.

Answer 1

I was able to distinguish between a scroll wheel on a mouse (not a Magic Mouse, but I suspect it will still work) and a trackpad using NSEvent's subtype:

enum {
   NSMouseEventSubtype           = NX_SUBTYPE_DEFAULT,
   NSTabletPointEventSubtype     = NX_SUBTYPE_TABLET_POINT,
   NSTabletProximityEventSubtype = NX_SUBTYPE_TABLET_PROXIMITY
   NSTouchEventSubtype             = NX_SUBTYPE_MOUSE_TOUCH
};

Answer 2

You should handle scrollWheel for the Magic Mouse and add a NSMagnificationGestureRecognizer for the pinch gesture on the trackpad. The two do not conflict with each-other but the swipe-scroll on the trackpad will trigger scrollWheel.