mootools 1.5.1 drag&drop with mobile support

gistfile1.txt

var Drag = new Class({

	Implements: [Events, Options],

	options: {/*
		onBeforeStart: function(thisElement){},
		onStart: function(thisElement, event){},
		onSnap: function(thisElement){},
		onDrag: function(thisElement, event){},
		onCancel: function(thisElement){},
		onComplete: function(thisElement, event){},*/
		snap: 6,
		unit: 'px',
		grid: false,
		style: true,
		limit: false,
		handle: false,
		invert: false,
		preventDefault: false,
		stopPropagation: false,
		compensateScroll: false,
		modifiers: {x: 'left', y: 'top'}
	},

	initialize: function(){
		var params = Array.link(arguments, {
			'options': Type.isObject,
			'element': function(obj){
				return obj != null;
			}
		});

		this.element = document.id(params.element);
		this.document = this.element.getDocument();
		this.setOptions(params.options || {});
		var htype = typeOf(this.options.handle);
		this.handles = ((htype == 'array' || htype == 'collection') ? $$(this.options.handle) : document.id(this.options.handle)) || this.element;
		this.mouse = {'now': {}, 'pos': {}};
		this.value = {'start': {}, 'now': {}};
		this.offsetParent = (function(el){
			var offsetParent = el.getOffsetParent();
			var isBody = !offsetParent || (/^(?:body|html)$/i).test(offsetParent.tagName);
			return isBody ? window : document.id(offsetParent);
		})(this.element);
		this.selection = 'selectstart' in document ? 'selectstart' : 'mousedown';

		this.compensateScroll = {start: {}, diff: {}, last: {}};

		if ('ondragstart' in document && !('FileReader' in window) && !Drag.ondragstartFixed){
			document.ondragstart = Function.from(false);
			Drag.ondragstartFixed = true;
		}

		this.bound = {
			start: this.start.bind(this),
			check: this.check.bind(this),
			drag: this.drag.bind(this),
			stop: this.stop.bind(this),
			cancel: this.cancel.bind(this),
			eventStop: Function.from(false),
			scrollListener: this.scrollListener.bind(this)
		};
		this.attach();
	},

	attach: function(){
		this.handles.addEvent('mousedown', this.bound.start);
		this.handles.addEvent('touchstart', this.bound.start);
		if (this.options.compensateScroll) this.offsetParent.addEvent('scroll', this.bound.scrollListener);
		return this;
	},

	detach: function(){
		this.handles.removeEvent('mousedown', this.bound.start);
		this.handles.removeEvent('touchstart', this.bound.start);
		if (this.options.compensateScroll) this.offsetParent.removeEvent('scroll', this.bound.scrollListener);
		return this;
	},

	scrollListener: function(){

		if (!this.mouse.start) return;
		var newScrollValue = this.offsetParent.getScroll();

		if (this.element.getStyle('position') == 'absolute'){
			var scrollDiff = this.sumValues(newScrollValue, this.compensateScroll.last, -1);
			this.mouse.now = this.sumValues(this.mouse.now, scrollDiff, 1);
		} else {
			this.compensateScroll.diff = this.sumValues(newScrollValue, this.compensateScroll.start, -1);
		}
		if (this.offsetParent != window) this.compensateScroll.diff = this.sumValues(this.compensateScroll.start, newScrollValue, -1);
		this.compensateScroll.last = newScrollValue;
		this.render(this.options);
	},

	sumValues: function(alpha, beta, op){
		var sum = {}, options = this.options;
		for (z in options.modifiers){
			if (!options.modifiers[z]) continue;
			sum[z] = alpha[z] + beta[z] * op;
		}
		return sum;
	},

	start: function(event){
		var options = this.options;

		if (event.rightClick) return;

		if (options.preventDefault) event.preventDefault();
		if (options.stopPropagation) event.stopPropagation();
		this.compensateScroll.start = this.compensateScroll.last = this.offsetParent.getScroll();
		this.compensateScroll.diff = {x: 0, y: 0};
		this.mouse.start = event.page;
		this.fireEvent('beforeStart', this.element);

		var limit = options.limit;
		this.limit = {x: [], y: []};

		var z, coordinates, offsetParent = this.offsetParent == window ? null : this.offsetParent;
		for (z in options.modifiers){
			if (!options.modifiers[z]) continue;

			var style = this.element.getStyle(options.modifiers[z]);

			// Some browsers (IE and Opera) don't always return pixels.
			if (style && !style.match(/px$/)){
				if (!coordinates) coordinates = this.element.getCoordinates(offsetParent);
				style = coordinates[options.modifiers[z]];
			}

			if (options.style) this.value.now[z] = (style || 0).toInt();
			else this.value.now[z] = this.element[options.modifiers[z]];

			if (options.invert) this.value.now[z] *= -1;

			this.mouse.pos[z] = event.page[z] - this.value.now[z];

			if (limit && limit[z]){
				var i = 2;
				while (i--){
					var limitZI = limit[z][i];
					if (limitZI || limitZI === 0) this.limit[z][i] = (typeof limitZI == 'function') ? limitZI() : limitZI;
				}
			}
		}

		if (typeOf(this.options.grid) == 'number') this.options.grid = {
			x: this.options.grid,
			y: this.options.grid
		};

		var events = {
			mousemove: this.bound.check,
			mouseup: this.bound.cancel,
			touchmove: this.bound.check,
			touchend: this.bound.cancel
		};
		events[this.selection] = this.bound.eventStop;
		this.document.addEvents(events);
	},

	check: function(event){
		if (this.options.preventDefault) event.preventDefault();
		var distance = Math.round(Math.sqrt(Math.pow(event.page.x - this.mouse.start.x, 2) + Math.pow(event.page.y - this.mouse.start.y, 2)));
		if (distance > this.options.snap){
			this.cancel();
			this.document.addEvents({
				mousemove: this.bound.drag,
				mouseup: this.bound.stop,
				touchmove: this.bound.drag,
				touchend: this.bound.stop
			});
			this.fireEvent('start', [this.element, event]).fireEvent('snap', this.element);
		}
	},

	drag: function(event){
		var options = this.options;
		if (options.preventDefault) event.preventDefault();
		this.mouse.now = this.sumValues(event.page, this.compensateScroll.diff, -1);

		this.render(options);
		this.fireEvent('drag', [this.element, event]);
	},

	render: function(options){
		for (var z in options.modifiers){
			if (!options.modifiers[z]) continue;
			this.value.now[z] = this.mouse.now[z] - this.mouse.pos[z];

			if (options.invert) this.value.now[z] *= -1;
			if (options.limit && this.limit[z]){
				if ((this.limit[z][1] || this.limit[z][1] === 0) && (this.value.now[z] > this.limit[z][1])){
					this.value.now[z] = this.limit[z][1];
				} else if ((this.limit[z][0] || this.limit[z][0] === 0) && (this.value.now[z] < this.limit[z][0])){
					this.value.now[z] = this.limit[z][0];
				}
			}
			if (options.grid[z]) this.value.now[z] -= ((this.value.now[z] - (this.limit[z][0]||0)) % options.grid[z]);
			if (options.style) this.element.setStyle(options.modifiers[z], this.value.now[z] + options.unit);
			else this.element[options.modifiers[z]] = this.value.now[z];
		}
	},

	cancel: function(event){
		this.document.removeEvents({
			mousemove: this.bound.check,
			mouseup: this.bound.cancel,
			touchmove: this.bound.check,
			touchend: this.bound.cancel
		});
		if (event){
			this.document.removeEvent(this.selection, this.bound.eventStop);
			this.fireEvent('cancel', this.element);
		}
	},

	stop: function(event){
		var events = {
			mousemove: this.bound.drag,
			mouseup: this.bound.stop,
			touchmove: this.bound.drag,
			touchend: this.bound.stop
		};
		events[this.selection] = this.bound.eventStop;
		this.document.removeEvents(events);
		this.mouse.start = null;
		if (event) this.fireEvent('complete', [this.element, event]);
	}

});