Position both the safari “touches” from a gesture event?

Question

I want to get the position (relative or otherwise) of the two fingers/touches inside a gesture event (gesturestart, gesturechange, gestureend) on mobile Safari (iOS: iPad/iPhone). I know that the gesture* events don't actually provide this in the event args but i thought there might be a 'trick' to getting this info. It would be great to get the coords of the fingers while tracking a gesture (eg. scaling and moving an object in the same gesture).

Can this be done?

Answer 1

It turns out that this information is not directly available via the 'gesture' events. The touch events are the key and i was able to get the touches collection and use the first two touches to derive a delta/midpoint of the two sets of coords. This seems to work.

Answer 2

There are three arrays in the returned event object for touch event:

1. touches
2. targetTouches
3. changedTouches

I can't remember where I originally found this info, but a quick Google search brings up http://www.sitepen.com/blog/2008/07/10/touching-and-gesturing-on-the-iphone/

Got it! https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariWebContent/HandlingEvents/HandlingEvents.html Down at "Handling Multi-Touch Events"