Under Mac OS X 10.10.2 and above we discovered that applications were no longer receiving the OS X positional touch events posted by our software, only the gesture events.
Our investigations revealed that positional touch events simply weren't being passed along to applications unless they came from a genuine Apple trackpad. When force click events were introduced in 10.10.2 we also discovered that our attempts to send force click events (from touch screens that support pressure) were also blocked. We suspect that the 10.10.2 update blocks both force click and now also positional events unless they come from a Apple trackpad and ignores any generated from a different source.
As it stands, we believe there will not be many OS X apps, with the exception of drawing apps, that use the position of individual touches and therefore we are not sure if this restriction will caused any real issues. Further, OS X's positional touch events were always meant to represent a relative ‘touch’ from a trackpad, not an absolute touch from a touch screen, and therefore not related to an absolute position on the desktop/within an application. Many applications rely on OS X gesture events and these are still processed which will satisfy gesture events such as trackSwipeEventWithOptions, rotateWithEvent, magnifyWithEvent to receive gesture information like rotation direction, swipe direction, zoom amount, etc. Applications that are responding to the low level multi touch events, such as touchesBegan, touchesMoved, touchesEnded will not be satisfied.
This limitation also affects other features, such as creating a signature using the trackpad (available when clicking "Create Signature" from the Markup toolbar) in Preview.