litejs/ui/polyfill/pointer.js

Single-page application framework

!function(Event, window) {
	var seq = 2
	, MS = "MSPointer"
	, DOWN = "pointerdown"
	, MOVE = "pointermove"
	, UP = "pointerup"
	, CANCEL = "pointercancel"
	, fixEv = Event.fixEv
	, fixFn = Event.fixFn
	, map = {
		d: "touchstart",
		m: "touchmove",
		u: "touchend",
		c: "touchcancel"
	}

	if (!window.PointerEvent) {
		var patched = (window.xhr || window)._patched || []

		// IE10
		if (window[MS + "Event"]) {
			fixEv[DOWN] = MS + "Down"
			fixEv[MOVE] = MS + "Move"
			fixEv[UP] = MS + "Up"
			fixEv[CANCEL] = MS + "Cancel"
			patched.push("pointer:MS")
			return
		}

		patched.push("pointer")

		fixEv[DOWN] = "mousedown"
		fixEv[MOVE] = "mousemove"
		fixEv[UP] = "mouseup"
		fixEv[CANCEL] = "mouseup"

		fixFn[DOWN] =
		fixFn[MOVE] =
		fixFn[UP] =
		fixEv[CANCEL] = function(el, _fn, ev) {
			var blockMouse
			if (window.TouchEvent) {
				// Calling preventDefault on a touchstart or the first touchmove event of a series
				// prevents the corresponding mouse events from firing.
				//
				// chrome://flags/ Touch Events API
				El.on(el, map[ev[7]], touchToPointer)
				mouseToPointer._rm = El.off.bind(el, el, map[ev[7]], touchToPointer)
			}
			return mouseToPointer
			function mouseToPointer(e) {
				if (blockMouse) {
					return
				}
				if (!e.target) e.target = el
				e.pointerId = 1
				e.pointerType = "mouse"
				e.width = e.height = 1
				e.pressure = e.type == "mouseup" ? 0 : 0.5
				if (el.setCapture) {
					if (e.type == "mousedown") el.setCapture(true)
					if (e.type == "mouseup") document.releaseCapture()
				}
				_fn.call(el, e)
			}
			function touchToPointer(e) {
				var touch
				, touches = e.changedTouches
				, preventDefault = e.preventDefault.bind(e)
				, stopPropagation = e.stopPropagation.bind(e)
				, i = 0
				for (; touch = touches[i++]; ) {
					touch.pointerId = touch.identifier + 2
					touch.pointerType = "touch"
					touch.width = 2 * (touch.radiusX || touch.webkitRadiusX || 0)
					touch.height = 2 * (touch.radiusY || touch.webkitRadiusY || 0)
					touch.pressure = touch.force || touch.webkitForce || 0.5
					touch.preventDefault = preventDefault
					touch.stopPropagation = stopPropagation
					_fn.call(el, touch)
				}
				blockMouse = e.touches[0]
			}
		}
	}
}(Event, this)