/* jScale Image Scaler v1.01
* Last updated: Aug 6th, 2009: Fixed bug when "ls (largest side)" option is used
* Author: JavaScript Kit at http://www.javascriptkit.com/
* Visit http://www.javascriptkit.com/script/script2/jScale/ for full source code
http://www.javascriptkit.com/script/script2/jscale/index.shtml

option 	Description
w 	String that sets the width of the image in pixels or percentage relative to the native width, ie: '250px' or '75%'. The height is then auto scaled accordingly.
h 	String that sets the height of the image in pixels or percentage relative to the native height. The width is then auto scaled accordingly.
ls 	String that sets the length of the longest side of the image in pixels or percentage relative to the native height. The length of the shorter side is then auto scaled accordingly.
speed 	Optional integer option that if set animates the image into its scaled dimensions per the desired duration, in milliseconds, ie: 2000.

jQuery(document).ready(function($){
  $('img').jScale({w:'80%'})
})
*/

jQuery.jScale={
	getnewSize:function(side, nvalue){
		var otherside=(side=="w")? "h" : "w"
		if (typeof nvalue=="undefined" || nvalue==null) //if this side has no explicit size set, scale it
			var newSize=this.ndimensions[otherside] * this.odimensions[side] / this.odimensions[otherside]
		else
			var newSize=(/%/.test(nvalue))? parseInt(nvalue)/100 * this.odimensions[side] : parseInt(nvalue)
		this.ndimensions[side]=Math.round(newSize)
	},
	getnewDimensions:function($, imgref, setting, callback){
 		//create temporary floating image to get original image's true dimensions (in case width/height attr set)
		var $tempimg=$('<img src="'+imgref.src+'" style="position:absolute; top:0; left:0; visibility:hidden" />').prependTo('body')
		this.odimensions={w:$tempimg.width(), h:$tempimg.height()} //get image dimensions
		var sortbysize=(this.odimensions.w>this.odimensions.h)? ["w","h"] : ["h","w"] //array to determine [largerside, shorterside]
		this.ndimensions={}
		if (typeof setting.ls!="undefined"){ //if setting.ls defined
			setting[sortbysize[0]]=setting.ls //set the correct side to the longest side's value setting
			setting[sortbysize[1]]=null
		}
		var sortbyavail=(setting.w)? ["w","h"] : (setting.h)? ["h","w"] : [] //check which side to work on based on availibility (which property is set by user)
		if (sortbyavail.length>0){
			this.getnewSize(sortbyavail[0], setting[sortbyavail[0]]) //work on side with property that's defined for sure first
			this.getnewSize(sortbyavail[1], setting[sortbyavail[1]]) //work on side with property that may or may not be defined last
			var callbackfunc=callback || function(){}
			if (setting.speed>0)
				$(imgref).animate({width:this.ndimensions.w+'px', height:this.ndimensions.h+'px'}, setting.speed, callbackfunc)
			else{
				$(imgref).css({width:this.ndimensions.w+'px', height:this.ndimensions.h+'px'})
				callbackfunc.call(imgref)
			}
		}
		$tempimg.remove()
	}
};

jQuery.fn.jScale=function(setting, callback){
	return this.each(function(){ //return jQuery obj
		var imgref=this
		if (typeof setting=="undefined" || imgref.tagName!="IMG")
			return true //skip to next matched element
		if (imgref.complete){ //account for IE not firing image.onload
			jQuery.jScale.getnewDimensions(jQuery, imgref, setting, callback)
		}
		else{
			$(this).bind('load', function(){
				jQuery.jScale.getnewDimensions(jQuery, imgref, setting, callback)
			})
		}
	})
};