ZeroClipboard源码阅读-2.简单注释

1.js代码

 

// Simple Set Clipboard System
// Author: Joseph Huckaby

var ZeroClipboard = {
	
	version: "1.0.7",
	clients: {}, // registered upload clients on page, indexed by id
	moviePath: 'ZeroClipboard.swf', // URL to movie
	nextId: 1, // ID of next movie
	
	$: function(thingy) {
		// simple DOM lookup utility function
		if (typeof(thingy) == 'string') thingy = document.getElementById(thingy);
		if (!thingy.addClass) {
			// extend element with a few useful methods
			thingy.hide = function() { this.style.display = 'none'; };
			thingy.show = function() { this.style.display = ''; };
			thingy.addClass = function(name) { this.removeClass(name); this.className += ' ' + name; };
			thingy.removeClass = function(name) {
				var classes = this.className.split(/\s+/);
				var idx = -1;
				for (var k = 0; k < classes.length; k++) {
					if (classes[k] == name) { idx = k; k = classes.length; }
				}
				if (idx > -1) {
					classes.splice( idx, 1 );
					this.className = classes.join(' ');
				}
				return this;
			};
			thingy.hasClass = function(name) {
				return !!this.className.match( new RegExp("\\s*" + name + "\\s*") );
			};
		}
		return thingy;
	},

    /**
     * 设置swf路径
     * @param path
     */
	setMoviePath: function(path) {
		// set path to ZeroClipboard.swf
		this.moviePath = path;
	},

    /**
     * 让具体的client(每个embem的swf)去接收事件
     * @param id
     * @param eventName
     * @param args
     */
	dispatch: function(id, eventName, args) {
		// receive event from flash movie, send to client		
		var client = this.clients[id];
		if (client) {
			client.receiveEvent(eventName, args);
		}
	},

    /**
     * 添加更多的client
     * @param id
     * @param client
     */
	register: function(id, client) {
		// register new client to receive events
		this.clients[id] = client;
	},

    /**
     * 不断迭代div id="d_clip_button"的父亲元素且 获得其父亲元素的大小位置,供新创建的div使用
     * @param obj
     * @param stopObj
     * @return {Object}
     */
	getDOMObjectPosition: function(obj, stopObj) {
		// get absolute coordinates for dom element
		var info = {
			left: 0, 
			top: 0, 
			width: obj.width ? obj.width : obj.offsetWidth, 
			height: obj.height ? obj.height : obj.offsetHeight
		};

		while (obj && (obj != stopObj)) {
			info.left += obj.offsetLeft;
			info.top += obj.offsetTop;
			obj = obj.offsetParent;
		}

		return info;
	},

    /**
     * new一个就设置一个的id,且注册
     * @param elem
     * @constructor
     */
	Client: function(elem) {
		// constructor for new simple upload client
		this.handlers = {};
		
		// unique ID
		this.id = ZeroClipboard.nextId++;
		this.movieId = 'ZeroClipboardMovie_' + this.id;
		
		// register client with singleton to receive flash events
		ZeroClipboard.register(this.id, this);
		
		// create movie
		if (elem) this.glue(elem);
	}
};

/**
 * 在链上添加属性
 * @type {Object}
 */
ZeroClipboard.Client.prototype = {
	
	id: 0, // unique ID for us
	ready: false, // whether movie is ready to receive events or not
	movie: null, // reference to movie object
	clipText: '', // text to copy to clipboard
	handCursorEnabled: true, // whether to show hand cursor, or default pointer cursor
	cssEffects: true, // enable CSS mouse effects on dom container
	handlers: null, // user event handlers

    /**
     * 这单词是黏上,粘合的意思
     * @param elem
     * @param appendElem
     * @param stylesToAdd
     */
	glue: function(elem, appendElem, stylesToAdd) {
		// glue to DOM element
		// elem can be ID or actual DOM element object

        //单例,因为每个swf关联一个按钮
		this.domElement = ZeroClipboard.$(elem);
		
		// float just above object, or zIndex 99 if dom element isn't set

        //若div id="d_clip_button"有zindex,那么新的div需比它大1
		var zIndex = 99;
		if (this.domElement.style.zIndex) {
			zIndex = parseInt(this.domElement.style.zIndex, 10) + 1;
		}

        //先查找
		if (typeof(appendElem) == 'string') {
			appendElem = ZeroClipboard.$(appendElem);
		}
        //若没有则appendElem=body
		else if (typeof(appendElem) == 'undefined') {
			appendElem = document.getElementsByTagName('body')[0];
		}

        //appendElem为一个大的容器,装着按钮的名字(div id="d_clip_button")和swf
        // 因此需要从this.domElement:(div id="d_clip_button")中不断查找父亲,然后获得这个元素真正的大小位置信息
		// find X/Y position of domElement
		var box = ZeroClipboard.getDOMObjectPosition(this.domElement, appendElem);

        //新建div罩在(div id="d_clip_button")上面
		// create floating DIV above element
		this.div = document.createElement('div');
		var style = this.div.style;
		style.position = 'absolute';
		style.left = '' + box.left + 'px';
		style.top = '' + box.top + 'px';
		style.width = '' + box.width + 'px';
		style.height = '' + box.height + 'px';
		style.zIndex = zIndex;

        //添加你的css
		if (typeof(stylesToAdd) == 'object') {
			for (addedStyle in stylesToAdd) {
				style[addedStyle] = stylesToAdd[addedStyle];
			}
		}
		
		// style.backgroundColor = '#f00'; // debug

        //添加新建div
		appendElem.appendChild(this.div);

        //植入swf代码
		this.div.innerHTML = this.getHTML( box.width, box.height );
	},
	
	getHTML: function(width, height) {
		// return HTML for movie
		var html = '';
		var flashvars = 'id=' + this.id + 
			'&width=' + width + 
			'&height=' + height;

        //兼容浏览器
		if (navigator.userAgent.match(/MSIE/)) {
			// IE gets an OBJECT tag
			var protocol = location.href.match(/^https/i) ? 'https://' : 'http://';
			html += '<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="'+protocol+'download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="'+width+'" height="'+height+'" id="'+this.movieId+'" align="middle"><param name="allowScriptAccess" value="always" /><param name="allowFullScreen" value="false" /><param name="movie" value="'+ZeroClipboard.moviePath+'" /><param name="loop" value="false" /><param name="menu" value="false" /><param name="quality" value="best" /><param name="bgcolor" value="#ffffff" /><param name="flashvars" value="'+flashvars+'"/><param name="wmode" value="transparent"/></object>';
		}
		else {
			// all other browsers get an EMBED tag
			html += '<embed id="'+this.movieId+'" src="'+ZeroClipboard.moviePath+'" loop="false" menu="false" quality="best" bgcolor="#ffffff" width="'+width+'" height="'+height+'" name="'+this.movieId+'" align="middle" allowScriptAccess="always" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" flashvars="'+flashvars+'" wmode="transparent" />';
		}
		return html;
	},
	
	hide: function() {
		// temporarily hide floater offscreen
        //不错的隐藏
		if (this.div) {
			this.div.style.left = '-2000px';
		}
	},
	
	show: function() {
		// show ourselves after a call to hide()
        //重新定位
		this.reposition();
	},
	
	destroy: function() {
		// destroy control and floater
        //销毁关联的元素
		if (this.domElement && this.div) {
			this.hide();
			this.div.innerHTML = '';
			
			var body = document.getElementsByTagName('body')[0];
			try { body.removeChild( this.div ); } catch(e) {;}

            //这个是:<div class="my_clip_button" id="d_clip_button"><b>Copy To Clipboard...</b></div>
			this.domElement = null;
            //这个是:新建的div
            this.div = null;
		}
	},
	
	reposition: function(elem) {
		// reposition our floating div, optionally to new container
		// warning: container CANNOT change size, only position
		if (elem) {
			this.domElement = ZeroClipboard.$(elem);
			if (!this.domElement) this.hide();
		}
		
		if (this.domElement && this.div) {
			var box = ZeroClipboard.getDOMObjectPosition(this.domElement);
			var style = this.div.style;
			style.left = '' + box.left + 'px';
			style.top = '' + box.top + 'px';
		}
	},

    /**
     * ready才设置文本
     * @param newText
     */
	setText: function(newText) {
		// set text to be copied to clipboard
		this.clipText = newText;
		if (this.ready) this.movie.setText(newText);
	},

    /**
     * 一个事件名多个处理函数
     * @param eventName
     * @param func
     */
	addEventListener: function(eventName, func) {
		// add user event listener for event
		// event types: load, queueStart, fileStart, fileComplete, queueComplete, progress, error, cancel
		eventName = eventName.toString().toLowerCase().replace(/^on/, '');
		if (!this.handlers[eventName]) this.handlers[eventName] = [];
		this.handlers[eventName].push(func);
	},

    /**
     * 设置光标图片
     * @param enabled
     */
	setHandCursor: function(enabled) {
		// enable hand cursor (true), or default arrow cursor (false)
		this.handCursorEnabled = enabled;
        //as中的movie已经通过addCallback注册回调
		if (this.ready) this.movie.setHandCursor(enabled);
	},

    /**
     * !!的妙用
     * @param enabled
     */
	setCSSEffects: function(enabled) {
		// enable or disable CSS effects on DOM container
		this.cssEffects = !!enabled;
	},
	
	receiveEvent: function(eventName, args) {
		// receive event from flash
		eventName = eventName.toString().toLowerCase().replace(/^on/, '');

        //先处理css
		// special behavior for certain events
		switch (eventName) {
			case 'load':
				// movie claims it is ready, but in IE this isn't always the case...
				// bug fix: Cannot extend EMBED DOM elements in Firefox, must use traditional function
				this.movie = document.getElementById(this.movieId);
				if (!this.movie) {
					var self = this;
					setTimeout( function() { self.receiveEvent('load', null); }, 1 );
					return;
				}
				
				// firefox on pc needs a "kick" in order to set these in certain cases
				if (!this.ready && navigator.userAgent.match(/Firefox/) && navigator.userAgent.match(/Windows/)) {
					var self = this;
					setTimeout( function() { self.receiveEvent('load', null); }, 100 );
					this.ready = true;
					return;
				}
				
				this.ready = true;
				this.movie.setText( this.clipText );
				this.movie.setHandCursor( this.handCursorEnabled );
				break;
			
			case 'mouseover':
				if (this.domElement && this.cssEffects) {
					this.domElement.addClass('hover');
					if (this.recoverActive) this.domElement.addClass('active');
				}
				break;
			
			case 'mouseout':
				if (this.domElement && this.cssEffects) {
					this.recoverActive = false;
					if (this.domElement.hasClass('active')) {
						this.domElement.removeClass('active');
						this.recoverActive = true;
					}
					this.domElement.removeClass('hover');
				}
				break;
			
			case 'mousedown':
				if (this.domElement && this.cssEffects) {
					this.domElement.addClass('active');
				}
				break;
			
			case 'mouseup':
				if (this.domElement && this.cssEffects) {
					this.domElement.removeClass('active');
					this.recoverActive = false;
				}
				break;
		} // switch eventName

        //再处理回调
		if (this.handlers[eventName]) {
			for (var idx = 0, len = this.handlers[eventName].length; idx < len; idx++) {
				var func = this.handlers[eventName][idx];
			
				if (typeof(func) == 'function') {
					// actual function reference
					func(this, args);
				}
				else if ((typeof(func) == 'object') && (func.length == 2)) {
					// PHP style object + method, i.e. [myObject, 'myMethod']
					func[0][ func[1] ](this, args);
				}
				else if (typeof(func) == 'string') {
					// name of function
					window[func](this, args);
				}
			} // foreach event handler defined
		} // user defined handler for event
	}
	
};

 

2.as部分代码

 

//调用js中的方法
button.addEventListener(MouseEvent.MOUSE_OVER, function(event:Event) {
				ExternalInterface.call( 'ZeroClipboard.dispatch', id, 'mouseOver', null );
			} );
			button.addEventListener(MouseEvent.MOUSE_OUT, function(event:Event) {
				ExternalInterface.call( 'ZeroClipboard.dispatch', id, 'mouseOut', null );
			} );
			button.addEventListener(MouseEvent.MOUSE_DOWN, function(event:Event) {
				ExternalInterface.call( 'ZeroClipboard.dispatch', id, 'mouseDown', null );
			} );
			button.addEventListener(MouseEvent.MOUSE_UP, function(event:Event) {
				ExternalInterface.call( 'ZeroClipboard.dispatch', id, 'mouseUp', null );
			} );
			
//添加回调,让js可以调用
			// external functions
			ExternalInterface.addCallback("setHandCursor", setHandCursor);
			ExternalInterface.addCallback("setText", setText);

 

3.主要流程:

as ->事件分配 ->js接收事件->处理css显示->执行用户注册的回调函数

 

4.over,过程粗略