code golf! 446 bytes minified (yui-compressor defaults)

thumbs.alunny.js

(function(window, document) {

    /**
     * Do not use thumbs.js on touch-enabled devices
     */
    if (document.ontouchstart) return;

    /**
     * Map touch events to mouse events
     */
    var eventMap = {
        'mousedown': 'touchstart',
        'mouseup':   'touchend',
        'mousemove': 'touchmove'
    }, key, eventObject;

    /**
     * Fire touch events
     *
     * Monitor mouse events and fire a touch event on the
     * object broadcasting the mouse event. This approach
     * likely has poorer performance than hijacking addEventListener
     * but it is a little more browser friendly.
     */
    for (key in eventMap) {
        document.addEventListener(key, function(e) {
            e.target.dispatchEvent(createTouchEvent(e));
        }, 0);
    }

    /**
     * Utility function to create a touch event.
     *
     * @param  name  {String} of the event
     * @return event {Object}
     */
    function createTouchEvent(e) {
        eventObject = document.createEvent('MouseEvents');

        eventObject.initMouseEvent(
            eventMap[e.type],
            e.cancelBubble,
            e.cancelable,
            e.view,
            e.detail,
            e.screenX,
            e.screenY,
            e.clientX,
            e.clientY,
            e.ctrlKey,
            e.altKey,
            e.shiftKey,
            e.metaKey,
            e.button,
            e.relatedTarget
        );

        return eventObject;
    };

})(window, document);

I'm not understanding some simple things here. The touchEvent you are dispatching is not formatted in a way that can be handled by a typical touch handler. Where is the targetTouches[] ? I think you should look at this: https://github.com/purplecabbage/GloveBox/blob/master/GloveBox.js#L364

Yea, they don't exist yet. Two reasons:

1. I have no need for targetTouches in my current projects
2. There is no standard... so I guess I would use the iOS implementation.

Do you think thumbs.js can play nice with GloveBox? I assumed GloveBox needed some extra mouse work. I can add the touch properties if you have a use for them.

Yeah, it could be made to work with glovebox.
GloveBox simply depends on the mouse events that come in being duck typed to touch events.

That said, I have some concerns about things like this: if (typeof document.ontouchstart != 'undefined') return;
Is an event handler guaranteed to be undefined if never set?

This test works in all current browsers that support touch events.
try { document.createEvent("TouchEvent"); } catch(e){return;}

Well, if you want, lets try to get thumbs.js working with GloveBox. Would be a good reason to get touch properties in thumbs.js. There is also an issue around touchmove. At the moment it's mapped to mousemove, but a touch move is really a mousedown + mousemove.

Being concerned about if (typeof document.ontouchstart != 'undefined') return; is fair. It works in the few browsers that I have tested on. I like try { document.createEvent("TouchEvent"); } catch(e){return;}. It feels more concrete.