/*
content-type: multipart/related; boundary="_cloudgamer"

--_cloudgamer
content-location:blankimage
content-transfer-encoding:base64

r0lgodlhaqabajeaaaaaap///////waaach5baeaaaialaaaaaabaaeaaaicvaeaow==
*/


var imagepreview = function(file, img, options) {
	
	this.file = $$(file);//�ļ�����
	this.img = $$(img);//Ԥ��ͼƭ����
	this._preload = null;//Ԥ��ͼƭ����
	this._data = "";//ͼ������
	this._upload = null;//remoteģʽʹ�õ��θ��ļ�����
	
	var opt = this._setoptions(options);
	
	this.action = opt.action;
	this.timeout = opt.timeout;
	this.ratio = opt.ratio;
	this.maxwidth = opt.maxwidth;
	this.maxheight = opt.maxheight;
	
	this.oncheck = opt.oncheck;
	this.onshow = opt.onshow;
	this.onerr = opt.onerr;
	
	//�������ݻ�ȡ����
	this._getdata = this._getdatafun(opt.mode);
	//����Ԥ����ʾ����
	this._show = opt.mode !== "filter" ? this._simpleshow : this._filtershow;
};
//�����������ȡģʽ
imagepreview.mode = $$b.ie7 || $$b.ie8 ? "filter" :
	$$b.firefox ? "domfile" :
	$$b.opera || $$b.chrome || $$b.safari ? "remote" : "simple";
//͸��ͼƭ
imagepreview.transparent = "images/2-2.png";

imagepreview.prototype = {
  //����ĭ������
  _setoptions: function(options) {
    this.options = {//ĭ��ֵ
		mode:		imagepreview.mode,//Ԥ��ģʽ
		ratio:		0,//�զ������
		maxwidth:	0,//����ͼ���
		maxheight:	0,//����ͼ�߶�
		oncheck:	function(){},//Ԥ�����ʱִ��
		onshow:		function(){},//Ԥ��ͼƭʱִ��
		onerr:		function(){},//Ԥ������ʱִ��
		//������remoteģʽʱ��ч
		action:		undefined,//����action
		timeout:	0//���ó�ʱ(0ϊ������)
    };
    return $$.extend(this.options, options || {});
  },
  //��ʼԤ��
  preview: function() {
	if ( this.file && false !== this.oncheck() ) {
		this._preview( this._getdata() );
	}
  },
  
  //����mode�������ݻ�ȡ����
  _getdatafun: function(mode) {
	switch (mode) {
		case "filter" :
			return this._filterdata;
		case "domfile" :
			return this._domfiledata;
		case "remote" :
			return this._remotedata;
		case "simple" :
		default :
			return this._simpledata;
	}
  },
  //�˾����ݻ�ȡ����
  _filterdata: function() {
	this.file.select();
	try{
		return document.selection.createrange().text;
	} finally { document.selection.empty(); }
  },
  //domfile���ݻ�ȡ����
  _domfiledata: function() {
	//return this.file.files[0].getasdataurl();
	return window.url.createobjecturl(this.file.files[0]);
  },
  //զ�����ݻ�ȡ����
  _remotedata: function() {
	this._setupload();
	this._upload && this._upload.upload();
  },
  //һ�����ݻ�ȡ����
  _simpledata: function() {
	return this.file.value;
  },
  
  //����remoteģʽ���θ��ļ�����
  _setupload: function() {
	if ( !this._upload && this.action !== undefined && typeof quickupload === "function" ) {
		var othis = this;
		this._upload = new quickupload(this.file, {
			onready: function(){
				this.action = othis.action; this.timeout = othis.timeout;
				var parameter = this.parameter;
				parameter.ratio = othis.ratio;
				parameter.width = othis.maxwidth;
				parameter.height = othis.maxheight;
			},
			onfinish: function(iframe){
				try{
					othis._preview( iframe.contentwindow.document.body.innerhtml );
				}catch(e){ othis._error("remote error"); }
			},
			ontimeout: function(){ othis._error("timeout error"); }
		});
	}
  },
  
  //Ԥ������
  _preview: function(data) {
	//��ֵ����ͬ��ֵ��ִ����ʾ
	if ( !!data && data !== this._data ) {
		this._data = data; this._show();
	}
  },
  
  //����һ��Ԥ��ͼƭ����
  _simplepreload: function() {
	if ( !this._preload ) {
		var preload = this._preload = new image(), othis = this,
			onload = function(){ othis._imgshow( othis._data, this.width, this.height ); };
		this._onload = function(){ this.onload = null; onload.call(this); }
		preload.onload = $$b.ie ? this._onload : onload;
		preload.onerror = function(){ othis._error(); };
	} else if ( $$b.ie ) {
		this._preload.onload = this._onload;
	}
  },
  //һ����ʾ
  _simpleshow: function() {
	this._simplepreload();
	this._preload.src = this._data;
  },
  
  //�����˾�Ԥ��ͼƭ����
  _filterpreload: function() {
	if ( !this._preload ) {
		var preload = this._preload = document.createelement("div");
		//���ز������˾�
		$$d.setstyle( preload, {
			width: "1px", height: "1px",
			visibility: "hidden", position: "absolute", left: "-9999px", top: "-9999px",
			filter: "progid:dximagetransform.microsoft.alphaimageloader(sizingmethod='image')"
		});
		//����body
		var body = document.body; body.insertbefore( preload, body.childnodes[0] );
	}
  },
  //�˾���ʾ
  _filtershow: function() {
	this._filterpreload();
	var preload = this._preload,
		data = this._data.replace(/[)'"%]/g, function(s){ return escape(escape(s)); });
	try{
		preload.filters.item("dximagetransform.microsoft.alphaimageloader").src = data;
	}catch(e){ this._error("filter error"); return; }
	//�����˾�����ʾ
	this.img.style.filter = "progid:dximagetransform.microsoft.alphaimageloader(sizingmethod='scale',src=\"" + data + "\")";
	//this._imgshow( imagepreview.transparent, preload.offsetwidth, preload.offsetheight );
	if ($$b.ie) {
	    if ($$b.ie8) {
	        this._imgshow(imagepreview.transparent, preload.offsetwidth, preload.offsetheight);
	    } else {
	        this._imgshow(data, preload.offsetwidth, preload.offsetheight);
	    }
	} else {
	    this._imgshow(imagepreview.transparent, preload.offsetwidth, preload.offsetheight);
	} 

  },
  
  //��ʾԤ��
  _imgshow: function(src, width, height) {
	var img = this.img, style = img.style,
		ratio = math.max( 0, this.ratio ) || math.min( 1,
				math.max( 0, this.maxwidth ) / width  || 1,
				math.max( 0, this.maxheight ) / height || 1
			);
	//����Ԥ���ߴ�
	style.width = math.round( width * ratio ) + "px";
	style.height = math.round( height * ratio ) + "px";
	//����src
	img.src = src;
	this.onshow();
  },
  
  //���ٳ���
  dispose: function() {
	//�����θ��ļ�����
	if ( this._upload ) {
		this._upload.dispose(); this._upload = null;
	}
	//����Ԥ��ͼƭ����
	if ( this._preload ) {
		var preload = this._preload, parent = preload.parentnode;
		this._preload = preload.onload = preload.onerror = null;
		parent && parent.removechild(preload);
	}
	//������ض���
	this.file = this.img = null;
  },
  //����
  _error: function(err) {
	this.onerr(err);
  }
}