/*Image Power Zoomer v1.1 (June 18th, 2010)
* This notice must stay intact for usage 
* Author: Dynamic Drive at http://www.dynamicdrive.com/
* Visit http://www.dynamicdrive.com/ for full source code
*/

//June 18th, 10: Adds ability to specify a different, higher resolution version of the original image as the image shown inside the magnifying glass.

jQuery.noConflict()

var ddpowerzoomer={
    dsetting: {defaultpower:2, powerrange:[2,7], magnifiersize:[75, 75]},
    mousewheelevt: (/Firefox/i.test(navigator.userAgent))? "DOMMouseScroll" : "mousewheel", //FF doesn't recognize mousewheel as of FF3.x
    $magnifier: {outer:null, inner:null, image:null},
    activeimage: null,

    movemagnifier:function(e, moveBol, zoomdir){
        var activeimage=ddpowerzoomer.activeimage //get image mouse is currently over
        var activeimginfo=activeimage.info
        var coords=activeimginfo.coords //get offset coordinates of image relative to upper left corner of page
        var $magnifier=ddpowerzoomer.$magnifier
        var magdimensions=activeimginfo.magdimensions //get dimensions of magnifier
        var power=activeimginfo.power.current
        var powerrange=activeimginfo.power.range
        var x=e.pageX-coords.left //get x coords of mouse within image (where top corner of image is 0)
        var y=e.pageY-coords.top
        if (moveBol==true){
            if (e.pageX>=coords.left && e.pageX<=coords.right && e.pageY>=coords.top && e.pageY<=coords.bottom)  //if mouse is within currently within boundaries of active base image
                $magnifier.outer.css({left:e.pageX-magdimensions[0]/2, top:e.pageY-magdimensions[1]/2})    //move magnifier so it follows the cursor
            else{ //if mouse is outside base image
                ddpowerzoomer.activeimage=null
                $magnifier.outer.hide() //hide magnifier
            }
        }
        else if (zoomdir){ //if zoom in
            var od=activeimginfo.dimensions //get dimensions of image
            var newpower=(zoomdir=="in")? Math.min(power+1, powerrange[1]) : Math.max(power-1, powerrange[0]) //get new power from zooming in or out
            var nd=[od[0]*newpower, od[1]*newpower] //calculate dimensions of new enlarged image within magnifier
            $magnifier.image.css({width:nd[0], height:nd[1]})
            activeimginfo.power.current=newpower //set current power to new power after magnification
        }
        power=activeimginfo.power.current //get current power
        var newx=-x*power+magdimensions[0]/2 //calculate x coord to move enlarged image
        var newy=-y*power+magdimensions[1]/2
        $magnifier.inner.css({left:newx, top:newy}) //move image wrapper within magnifier so the correct image area is shown
    },

    setupimage:function($, imgref, options){
        var s=jQuery.extend({}, ddpowerzoomer.dsetting, options)
        var $imgref=$(imgref)
        imgref.info={ //create object to remember various info regarding image 
            power: {current:s.defaultpower, range:s.powerrange},
            magdimensions: s.magnifiersize,
            dimensions: [$imgref.width(), $imgref.height()],
            coords: null
        }
        $imgref.unbind('mouseenter').mouseenter(function(e){ //mouseenter event over base image
            var $magnifier=ddpowerzoomer.$magnifier
            $magnifier.outer.css({width:s.magnifiersize[0], height:s.magnifiersize[1]}) //set magnifier's size
            var offset=$imgref.offset() //get image offset from document
            var power=imgref.info.power.current
            $magnifier.inner.html('<img src="'+options.largeimagesrc+'"/>') //get base image's src and create new image inside magnifier based on it
            $magnifier.image=$magnifier.outer.find('img:first')
                .css({width:imgref.info.dimensions[0]*power, height:imgref.info.dimensions[1]*power}) //set size of enlarged image
            var coords={left:offset.left, top:offset.top, right:offset.left+imgref.info.dimensions[0], bottom:offset.top+imgref.info.dimensions[1]}
            imgref.info.coords=coords //remember left, right, and bottom right coordinates of image relative to doc
            $magnifier.outer.show()
            ddpowerzoomer.activeimage=imgref
        })
    },

    
    init:function($){
        var $magnifier=$('<div style="position:absolute;width:100px;height:100px;display:none;overflow:hidden;border:1px solid black;" />')
            .append('<div style="position:relative;left:0;top:0;" />')
            .appendTo(document.body) //create magnifier container and add to doc
        ddpowerzoomer.$magnifier={outer:$magnifier, inner:$magnifier.find('div:eq(0)'), image:null} //reference and remember various parts of magnifier
        $magnifier=ddpowerzoomer.$magnifier
        $(document).unbind('mousemove.trackmagnifier').bind('mousemove.trackmagnifier', function(e){ //bind mousemove event to doc
            if (ddpowerzoomer.activeimage){ //if mouse is currently over a magnifying image
                ddpowerzoomer.movemagnifier(e, true) //move magnifier
            }
        }) //end document.mousemove

        $magnifier.outer.bind(ddpowerzoomer.mousewheelevt, function(e){ //bind mousewheel event to magnifier
            if (ddpowerzoomer.activeimage){
                var delta=e.detail? e.detail*(-120) : e.wheelDelta //delta returns +120 when wheel is scrolled up, -120 when scrolled down
                if (delta<=-120){ //zoom out
                    ddpowerzoomer.movemagnifier(e, false, "out")
                }
                else{ //zoom in
                    ddpowerzoomer.movemagnifier(e, false, "in")
                }
                e.preventDefault()
            }
        })
    }
} //ddpowerzoomer

jQuery.fn.addpowerzoom=function(options){
    var $=jQuery
    return this.each(function(){ //return jQuery obj
        if (this.tagName!="IMG")
            return true //skip to next matched element
        if (typeof options=="undefined")
            options={}
        if (options.largeimage && options.largeimage.length>0){ //preload large image?
            options.preloadimg=new Image()
            options.preloadimg.src=options.largeimage
        }
        var $imgref=$(this)
        options.largeimagesrc=(options.preloadimg)? options.preloadimg.src : $imgref.attr('src')
        if (parseInt(this.style.width)>0 && parseInt(this.style.height)>0) //if image has explicit CSS width/height defined
            ddpowerzoomer.setupimage($, this, options)
        else if (this.complete){ //account for IE not firing image.onload
            ddpowerzoomer.setupimage($, this, options)
        }
        else{
            $imgref.bind('load', function(){
                ddpowerzoomer.setupimage($, this, options)
            })
        }
    })
}

jQuery(document).ready(function($){ //initialize power zoomer on DOM load
    ddpowerzoomer.init($)
})