Mootools Gallery ZoomBox Plugin

// Create the Mootools ZoomBox Class
var zoomBox = new Class({
 
	Implements : Options,
	// Editable Settings
    options: {
		zb_class:     '.zoomBox',                    // class of anchors/images to find on page.
		zb_element:   'zb_image',                    // id of zppmBox pop-up div
		zb_loader:    '/assets/images/loading.gif',  // path to loading image
		scale_image:  true,                          // scale large image if it is bigger than our screen size, bool true/false
		win_width:    1024,                          // basic window width, ignore
		win_height:   768                            // basic window height, ignore
    },
 
	initialize: function(options){
		// set options and internal settings
		this.setOptions(options);
		this.setWindowSize();
		this.currentIndex;
		this.images = new Array();
		this.positions = new Array();
 
		// create our loading image
		this.zb_loading = new Element('img', { 
			'id'    : 'zb_loading', 
			'src'   : this.options.zb_loader,
			'styles': { 
				'position': 'absolute',
				'display' : 'none',
				'left'    : 0,
				'top'     : 0
			}
		}).inject(document.body, 'bottom');
 
		// scan page for our class.
		this.thumbs = $$(this.options.zb_class);
 
		var self = this;
 
		// attach each image.
		this.thumbs.each(function(zb, index) {
			self.attach(zb, index);
		});
 
		// add event listener if the user resizes their window to scale max size of images.
		window.addEvent('resize', self.setWindowSize.bindWithEvent(this));
 
	},
 
 
	// attach out image and add event listeners.
	attach: function(zb, index) {
		var self     = this;
		// is we manually attach a new element this is needed.
		if(index == undefined) {
			index = (self.length + 1);
		}
		// set our basic width/heights.
		var zb_fx;
		var zb_src   = zb.get('href');
		var zb_org   = zb.getElements('img')[0];
		self.positions[index] = {};
		self.positions[index].zb_left = zb_org.getPosition().x;
		self.positions[index].zb_top  = zb_org.getPosition().y;
		// add out click event.
		zb.addEvent('click', function(clk) {
			new Event(clk).stop();
			// no point opening it, if its already open !
			if(!document.id(self.options.zb_element) || !document.id(self.options.zb_element).get('src').match(zb.get('href'))) {
				// add out loading gif to the image about to be opened.
				self.zb_loading.setStyles({
					'display' : '',
					'top'     : self.positions[index].zb_top,
					'left'    : self.positions[index].zb_left
				});
				// if we have one open, let it be gone
				if(document.id(self.options.zb_element)) {
					self.close(self.currentIndex);
				}
				// set current index.
				self.currentIndex = index;
				// create and place on top of the thumbnail. but keep it hidden.
				self.images[index] = new Element('img', { 
					'id'    : self.options.zb_element, 
					'src'   : zb_src,
					'styles': { 
						'position': 'absolute',
						'opacity' : 0,
						'left'    : self.positions[index].zb_left,
						'top'     : self.positions[index].zb_top
					}
				})
				.addClass('shadow') // we don't need this. but its basic styling for large image.
				.inject(document.body, 'bottom') // inject at teh bottom of our page.
				.addEvent('click', function(clk) {
					// bind out close even on clicking the new large image
					new Event(clk).stop();
					self.close(index);
				})
				// bind a load event so once the large image has loaded, we open it.
				.addEvent('load', function() {
					// get our large image size
					var zb_width  = self.images[index].getWidth();
					var zb_height = self.images[index].getHeight();
					// see if we need to scale it, so the image fits on screen.
					if(self.options.scale_image) {
						if(self.options.win_width < zb_width) {
							zb_width  = (self.options.win_width - 50);
							zb_height = (zb_width / zb_height) * zb_width;
						} 
						if(self.options.win_height < zb_height) {
							zb_height = Math.floor(self.options.win_height - 50);
							zb_width  = Math.floor((zb_height / zb_width) * zb_height);
						}
					}
					// set the imahe the size of the thumbnail
					self.images[index].setStyles({
						'width'   : zb_org.getWidth(),
						'height'  : zb_org.getHeight(),
						'cursor'  : 'pointer'
					});
					// hide teh loading gif/indicator 
					self.zb_loading.setStyle('display', 'none');
					// animate it BIG ! and center it on the screen
					var zb_fx = new Fx.Morph(self.images[index]).start({
						'top'     : ((self.options.win_height / 2) - (zb_height / 2)) + window.getScroll().y,
						'left'    : ((self.options.win_width / 2) - (zb_width / 2)),
						'width'   : zb_width,
						'height'  : zb_height,
						'opacity' : 1
					});
				});
			} else {
				// we have used it before, lets load it up.
				self.images[index].fireEvent('load');
			}
			// bind the 'escape' key to close the current image.
			window.addEvent('keyup', function(key) {
				if(key.code == 27) {
					self.close(index);
				} 
			});
		});
	},
 
	close: function(index) {
		var self = this;
		var zb_fx = new Fx.Morph(self.images[index], { 
			onComplete: function() {
				document.id(self.options.zb_element)
					.fade(0)
					.dispose();
			} 
		}).start({
			'top'     : self.positions[index].zb_top,
			'left'    : self.positions[index].zb_left,
			'width'   : 100,
			'height'  : 100,
			'opacity' : 0
		});
		window.removeEvents('keyup');
	},
 
	setWindowSize: function() {
 
		this.options.win_width = window.getWidth();
		this.options.win_height = window.getHeight();
 
	}
 
});