angularJS ngTouch - can't get relative coordinates

Question

using ngClick i am easily able to get the relative click coordinates from event.offsetX. however using ngTouch there seems to be no obvious way of doing this. i've inspected the event.originalEvent.changedTouches[] array thoroughly but all of the coordinates in my touch event are absolute.

the only way appears to be traversing the DOM and getting each element's offset relative to its parent...a terrible solution indeed. am i missing something? where is the easy access to the x,y coordinates of the touch relative to the listening element?

Answer 1

i ended up using jQuery to hack out a solution - something that i've found occasionally necessary even when trying to avoid it and go all angular. since the relative coordinates aren't provided you have to figure out the viewport offset of the target element being clicked.

perhaps ngTouch is so young that the authors hadn't thought to add this by default, but it feels like an oversight to me.

i should note that i also discovered what appears to be an ngTouch bug where, if you tap just outside the ng-click element but close enough that the touch overlaps into the element, it fires with a MouseEvent whereas if you tap well inside the element it uses a TouchEvent instead. getting the offsetX parameter is different for each of these events as shown below.

scope.click = function( event )
{
    var offsetX = null;
    if( event.originalEvent.changedTouches )
    {
        offsetX = event.originalEvent.changedTouches[0].clientX - $(event.currentTarget).offset().left;
    }
    else
    {
        offsetX = event.offsetX;
    }

    ... do stuff with offsetX ...
}