events.js

一个用javascript开发的可以拖拽表单的例子,很精典.

/* Copyright (c) 2005 Tim Taylor Consulting (see LICENSE.txt) */

ToolMan._eventsFactory = {
	fix : function(event) {
		if (!event) event = window.event

		if (event.target) {
			if (event.target.nodeType == 3) event.target = event.target.parentNode
		} else if (event.srcElement) {
			event.target = event.srcElement
		}

		return event
	},

	register : function(element, type, func) {
		if (element.addEventListener) {
			element.addEventListener(type, func, false)
		} else if (element.attachEvent) {
			if (!element._listeners) element._listeners = new Array()
			if (!element._listeners[type]) element._listeners[type] = new Array()
			var workaroundFunc = function() {
				func.apply(element, new Array())
			}
			element._listeners[type][func] = workaroundFunc
			element.attachEvent('on' + type, workaroundFunc)
		}
	},

	unregister : function(element, type, func) {
		if (element.removeEventListener) {
			element.removeEventListener(type, func, false)
		} else if (element.detachEvent) {
			if (element._listeners 
					&& element._listeners[type] 
					&& element._listeners[type][func]) {

				element.detachEvent('on' + type, 
						element._listeners[type][func])
			}
		}
	}
}