jDragAndDrop.js

(function() {
	"use strict";

	var DragAndDrop = J.Class("DragAndDrop");

	DragAndDrop.prototype.init = function (element) {
		this.E = element;
		/*
		||	Polyfill for IE7
		||	*/
		if (!this.E.hasAttribute) {
			this.E.hasAttribute = function (name) {
				var returnVar = false;
				if (this[name]) {
					returnVar = true;
				}
				return returnVar;
			};
		}
	};

	DragAndDrop.prototype.onDrag = function (e) { e.preventDefault(); };
	DragAndDrop.prototype.onEnd = function (e) { e.preventDefault(); };
	DragAndDrop.prototype.onEnter = function (e) { e.preventDefault(); };
	DragAndDrop.prototype.onOver = function (e) { e.preventDefault(); };
	DragAndDrop.prototype.onLeave = function (e) { e.preventDefault(); };
	DragAndDrop.prototype.onDrop = function (e) { e.preventDefault(); };

	DragAndDrop.prototype.setListeners = function () {
			/*	@ var events;
			||	Aspect Orientated to intercept old IE and map the events correctly with the need to extra code
			||	in the event handlers
			||	*/
			var events = {
					"dragstart" : this.onDrag,
					"dragend" : this.onEnd,
					"dragover" : this.onOver,
					"dragenter" : this.onEnter,
					"dragleave" : this.onLeave,
					"drop" : this.onDrop
			};
			/*
			||	Event Handlers closure for legacy support (IE 7 & 8)
			||	*/
			function eventHandler(E) {
					var e = E || window.event;
					e.cancelBubble = true;
					if (!e.target) {
							e.target = e.srcElement;
					}
					if (!e.preventDefault) {
							e.preventDefault = function () {this.returnValue = false; };
					}
					events[e.type](e);
			}

			if (!!window.addEventListener) {
					/*
					||	Remove prior listeners if they are being reset to prevent double event firing.
					||	*/
					if (this.E.hasAttribute('draggable') && this.E.getAttribute('draggable') === "true") {
							this.E.removeEventListener("dragstart", this.onDrag, false);
							this.E.removeEventListener("dragend", this.onEnd, false);
					} else {
							this.E.removeEventListener("dragover", this.onOver, false);
							this.E.removeEventListener("dragenter", this.onEnter, false);
							this.E.removeEventListener("dragleave", this.onLeave, false);
							this.E.removeEventListener("drop", this.onDrop, false);
					}
					/*
					||	Add All event listeners, defaults will should be set to cancel default actions as per spec?
					||	*/
					if (this.E.hasAttribute('draggable') && this.E.getAttribute('draggable') === "true") {
							this.E.addEventListener("dragstart", this.onDrag, false);
							this.E.addEventListener("dragend", this.onEnd, false);
							/*
							||	IE9 Support event handler
							||	*/
							if (this.E.dragDrop) {
									this.E.addEventListener("mousemove",
											function (e) {
													if (window.event) {
															var t = e.target;
															if (window.event.button === 1) {
																	t.dragDrop();
															}
													}
							return false;
											}, false);
							}
					} else {
							this.E.addEventListener("dragover", this.onOver, false);
							this.E.addEventListener("dragenter", this.onEnter, false);
							this.E.addEventListener("dragleave", this.onLeave, false);
							this.E.addEventListener("drop", this.onDrop, false);
					}
			} else {
					/*
					||	If IE 8 or 7, then use old event triggers and polyfill handler.
					||	*/
					if (this.E.hasAttribute('draggable') && this.E.getAttribute('draggable') === "true") {
							this.E.ondragstart = eventHandler;
							this.E.ondragend = eventHandler;
							/*
							||	IE requires manual instigation of drag and drop for non anchor/ img elements.
							||	*/
							this.E.onmousemove = function (E) {
									var e = E || window.event, t = e.srcElement;
									if (window.event.button === 1) {
											t.dragDrop();
									}
							};
					} else {
							this.E.ondragover = eventHandler;
							this.E.ondragenter = eventHandler;
							this.E.ondragleave = eventHandler;
							this.E.ondrop = eventHandler;
					}
			}
	};

	DragAndDrop.prototype.toString = function () {
			return "Drag And Drop Element";
	};

	J.export("DragAndDrop", DragAndDrop);
}());