Touch Events

Lens supports multi-touch interaction. When LuminAR registers a touch, Lens fires and event on the touched element, and this event will bubble up to parent elements.

There are three event types: lens:touchstart is fired when a touch begins, lens:touchmove is fired any time a finger that is touching moves, and lens:touchend is fired when a finger stops touching.

Each event has four properties: touches is a MultiTouch containing all fingers currently touching the surface. targetTouches is a MultiTouch containing all touches that started out on the element the event is fired on. changedTouches is a MultiTouch containing the subset of targetTouches involved in the event: for a lens:touchstart event, this will be the fingers that started touching; for a lens:touchmove event, this will be the fingers that moved, and for a lens:touchend event this will be the fingers that stopped touching. Finally, the touch property is a single Touch such that touch = changedTouches[0].

For further discussion of these properties, see http://www.w3.org/TR/touch-events/#usage-examples and http://stackoverflow.com/a/7236327/2005979

As an alernative to watching for lens:touchmove and lens:touchend events, you can use MultiTouch#moved, MultiTouch#ended, Touch#moved, and Touch#ended.