//Step Carousel Viewer: By Dynamic Drive, at http://www.dynamicdrive.com
//** Created: March 19th, 08'
//** Aug 16th, 08'- Updated to v 1.4:
//1) Adds ability to set speed/duration of panel animation (in milliseconds)
//2) Adds persistence support, so the last viewed panel is recalled when viewer returns within same browser session
//3) Adds ability to specify whether panels should stop at the very last and first panel, or wrap around and start all over again
//4) Adds option to specify two navigational image links positioned to the left and right of the Carousel Viewer to move the panels back and forth

//** Aug 27th, 08'- Nav buttons (if enabled) also repositions themselves now if window is resized

//** Sept 23rd, 08'- Updated to v 1.6:
//1) Carousel now stops at the very last visible panel, instead of the last panel itself. In other words, no more white space at the end.
//2) Adds ability for Carousel to auto rotate dictated by the new parameter: autostep: {enable:true, moveby:1, pause:3000}
//2i) During Auto Rotate, Carousel pauses onMouseover, resumes onMouseout. Clicking Carousel halts auto rotate.

//** Oct 22nd, 08'- Updated to v 1.6.1, which fixes functions stepBy() and stepTo() not stopping auto stepping of Carousel when called.

var stepcarousel = {
	ajaxloadingmsg: '<div style="margin: 1em; font-weight: bold"><img src="ajaxloadr.gif" style="vertical-align: middle" /> Fetching Content. Please wait...</div>', //customize HTML to show while fetching Ajax content
	defaultbuttonsfade: 0.4, //Fade degree for disabled nav buttons (0=completely transparent, 1=completely opaque)
	configholder: {},

	getCSSValue: function(val) { //Returns either 0 (if val contains 'auto') or val as an integer
		return (val == "auto") ? 0 : parseInt(val)
	},

	getremotepanels: function($, config) { //function to fetch external page containing the panel DIVs
		config.$belt.html(this.ajaxloadingmsg)
		$.ajax({
			url: config.contenttype[1], //path to external content
			async: true,
			error: function(ajaxrequest) {
				config.$belt.html('Error fetching content.<br />Server Response: ' + ajaxrequest.responseText)
			},
			success: function(content) {
				config.$belt.html(content)
				config.$panels = config.$gallery.find('.' + config.panelclass)
				stepcarousel.alignpanels($, config)
			}
		})
	},

	getoffset: function(what, offsettype) {
		return (what.offsetParent) ? what[offsettype] + this.getoffset(what.offsetParent, offsettype) : what[offsettype]
	},

	getCookie: function(Name) {
		var re = new RegExp(Name + "=[^;]+", "i"); //construct RE to search for target name/value pair
		if (document.cookie.match(re)) //if cookie found
			return document.cookie.match(re)[0].split("=")[1] //return its value
		return null
	},

	setCookie: function(name, value) {
		document.cookie = name + "=" + value
	},

	fadebuttons: function(config, currentpanel) {
		config.$leftnavbutton.fadeTo('fast', currentpanel == 0 ? this.defaultbuttonsfade : 1)
		config.$rightnavbutton.fadeTo('fast', currentpanel == config.lastvisiblepanel ? this.defaultbuttonsfade : 1)
	},

	addnavbuttons: function(config, currentpanel) {
		config.$leftnavbutton = $('<img src="' + config.defaultbuttons.leftnav[0] + '">').css({ zIndex: 50, position: 'absolute', left: config.offsets.left + config.defaultbuttons.leftnav[1] + 'px', top: config.offsets.top + config.defaultbuttons.leftnav[2] + 'px', cursor: 'hand', cursor: 'pointer' }).attr({ title: 'Move back ' + config.defaultbuttons.moveby + ' panel' }).appendTo('body')
		config.$rightnavbutton = $('<img src="' + config.defaultbuttons.rightnav[0] + '">').css({ zIndex: 50, position: 'absolute', left: config.offsets.left + config.$gallery.get(0).offsetWidth + config.defaultbuttons.rightnav[1] + 'px', top: config.offsets.top + config.defaultbuttons.rightnav[2] + 'px', cursor: 'hand', cursor: 'pointer' }).attr({ title: 'Move forward by ' + config.defaultbuttons.moveby + ' panel' }).appendTo('body')
		config.$leftnavbutton.bind('click', function() { //assign nav button event handlers
			stepcarousel.stepBy(config.galleryid, -config.defaultbuttons.moveby)
		})
		config.$rightnavbutton.bind('click', function() { //assign nav button event handlers
			stepcarousel.stepBy(config.galleryid, config.defaultbuttons.moveby)
		})
		if (config.panelbehavior.wraparound == false) { //if carousel viewer should stop at first or last panel (instead of wrap back or forth)
			this.fadebuttons(config, currentpanel)
		}
		return config.$leftnavbutton.add(config.$rightnavbutton)
	},

	stopautostep: function(config) {
		clearTimeout(config.steptimer)
		clearTimeout(config.resumeautostep)
	},

	alignpanels: function($, config) {
		var paneloffset = 0
		config.paneloffsets = [paneloffset] //array to store upper left offset of each panel (1st element=0)
		config.panelwidths = [] //array to store widths of each panel
		config.$panels.each(function(index) { //loop through panels
			var $currentpanel = $(this)
			$currentpanel.css({ float: 'none', position: 'absolute', left: paneloffset + 'px' }) //position panel
			$currentpanel.bind('click', function(e) { return config.onpanelclick(e.target) }) //bind onpanelclick() to onclick event
			paneloffset += stepcarousel.getCSSValue($currentpanel.css('marginRight')) + parseInt($currentpanel.get(0).offsetWidth || $currentpanel.css('width')) //calculate next panel offset
			config.paneloffsets.push(paneloffset) //remember this offset
			config.panelwidths.push(paneloffset - config.paneloffsets[config.paneloffsets.length - 2]) //remember panel width
		})
		config.paneloffsets.pop() //delete last offset (redundant)
		var addpanelwidths = 0
		var lastpanelindex = config.$panels.length - 1
		config.lastvisiblepanel = lastpanelindex
		for (var i = config.$panels.length - 1; i >= 0; i--) {
			addpanelwidths += (i == lastpanelindex ? config.panelwidths[lastpanelindex] : config.paneloffsets[i + 1] - config.paneloffsets[i])
			if (config.gallerywidth > addpanelwidths) {
				config.lastvisiblepanel = i //calculate index of panel that when in 1st position reveals the very last panel all at once based on gallery width
			}
		}
		config.$belt.css({ width: paneloffset + 'px' }) //Set Belt DIV to total panels' widths
		config.currentpanel = (config.panelbehavior.persist) ? parseInt(this.getCookie(window[config.galleryid + "persist"])) : 0 //determine 1st panel to show by default
		config.currentpanel = (typeof config.currentpanel == "number" && config.currentpanel < config.$panels.length) ? config.currentpanel : 0
		if (config.currentpanel != 0) {
			var endpoint = config.paneloffsets[config.currentpanel] + (config.currentpanel == 0 ? 0 : config.beltoffset)
			config.$belt.css({ left: -endpoint + 'px' })
		}
		if (config.defaultbuttons.enable == true) { //if enable default back/forth nav buttons
			var $navbuttons = this.addnavbuttons(config, config.currentpanel)
			$(window).bind("load resize", function() { //refresh position of nav buttons when page loads/resizes, in case offsets weren't available document.oncontentload
				config.offsets = { left: stepcarousel.getoffset(config.$gallery.get(0), "offsetLeft"), top: stepcarousel.getoffset(config.$gallery.get(0), "offsetTop") }
				config.$leftnavbutton.css({ left: config.offsets.left + config.defaultbuttons.leftnav[1] + 'px', top: config.offsets.top + config.defaultbuttons.leftnav[2] + 'px' })
				config.$rightnavbutton.css({ left: config.offsets.left + config.$gallery.get(0).offsetWidth + config.defaultbuttons.rightnav[1] + 'px', top: config.offsets.top + config.defaultbuttons.rightnav[2] + 'px' })
			})
		}
		if (config.autostep && config.autostep.enable) { //enable auto stepping of Carousel?		
			var $carouselparts = config.$gallery.add(typeof $navbuttons != "undefined" ? $navbuttons : null)
			$carouselparts.bind('click', function() {
				stepcarousel.stopautostep(config)
				config.autostep.status = "stopped"
			})
			$carouselparts.hover(function() { //onMouseover
				stepcarousel.stopautostep(config)
				config.autostep.hoverstate = "over"
			}, function() { //onMouseout
				if (config.steptimer && config.autostep.hoverstate == "over" && config.autostep.status != "stopped") {
					config.resumeautostep = setTimeout(function() {
						stepcarousel.autorotate(config.galleryid)
						config.autostep.hoverstate = "out"
					}, 500)
				}
			})
			config.steptimer = setTimeout(function() { stepcarousel.autorotate(config.galleryid) }, config.autostep.pause) //automatically rotate Carousel Viewer
		} //end enable auto stepping check
		this.statusreport(config.galleryid)
		config.oninit()
		config.onslideaction(this)
	},

	stepTo: function(galleryid, pindex) { /*User entered pindex starts at 1 for intuitiveness. Internally pindex still starts at 0 */
		var config = stepcarousel.configholder[galleryid]
		if (typeof config == "undefined") {
			alert("There's an error with your set up of Carousel Viewer \"" + galleryid + "\"!")
			return
		}
		stepcarousel.stopautostep(config)
		var pindex = Math.min(pindex - 1, config.paneloffsets.length - 1)
		var endpoint = config.paneloffsets[pindex] + (pindex == 0 ? 0 : config.beltoffset)
		if (config.panelbehavior.wraparound == false && config.defaultbuttons.enable == true) { //if carousel viewer should stop at first or last panel (instead of wrap back or forth)
			this.fadebuttons(config, pindex)
		}
		config.$belt.animate({ left: -endpoint + 'px' }, config.panelbehavior.speed, function() { config.onslideaction(this) })
		config.currentpanel = pindex
		this.statusreport(galleryid)
	},

	stepBy: function(galleryid, steps) { //isauto if defined indicates stepBy() is being called automatically
		var config = stepcarousel.configholder[galleryid]
		if (typeof config == "undefined") {
			alert("There's an error with your set up of Carousel Viewer \"" + galleryid + "\"!")
			return
		}
		stepcarousel.stopautostep(config)
		var direction = (steps > 0) ? 'forward' : 'back' //If "steps" is negative, that means backwards
		var pindex = config.currentpanel + steps //index of panel to stop at
		if (config.panelbehavior.wraparound == false) { //if carousel viewer should stop at first or last panel (instead of wrap back or forth)
			pindex = (direction == "back" && pindex <= 0) ? 0 : (direction == "forward") ? Math.min(pindex, config.lastvisiblepanel) : pindex
			if (config.defaultbuttons.enable == true) { //if default nav buttons are enabled, fade them in and out depending on if at start or end of carousel
				stepcarousel.fadebuttons(config, pindex)
			}
		}
		else { //else, for normal stepBy behavior
			if (pindex > config.lastvisiblepanel && direction == "forward") {
				//if destination pindex is greater than last visible panel, yet we're currently not at the end of the carousel yet
				pindex = (config.currentpanel < config.lastvisiblepanel) ? config.lastvisiblepanel : 0
			}
			else if (pindex < 0 && direction == "back") {
				//if destination pindex is less than 0, yet we're currently not at the beginning of the carousel yet
				pindex = (config.currentpanel > 0) ? 0 : config.lastvisiblepanel /*wrap around left*/
			}
		}
		var endpoint = config.paneloffsets[pindex] + (pindex == 0 ? 0 : config.beltoffset) //left distance for Belt DIV to travel to
		if (pindex == 0 && direction == 'forward' || config.currentpanel == 0 && direction == 'back' && config.panelbehavior.wraparound == true) { //decide whether to apply "push pull" effect
			config.$belt.animate({ left: -config.paneloffsets[config.currentpanel] - (direction == 'forward' ? 100 : -30) + 'px' }, 'normal', function() {
				config.$belt.animate({ left: -endpoint + 'px' }, config.panelbehavior.speed, function() { config.onslideaction(this) })
			})
		}
		else
			config.$belt.animate({ left: -endpoint + 'px' }, config.panelbehavior.speed, function() { config.onslideaction(this) })
		config.currentpanel = pindex
		this.statusreport(galleryid)
	},

	autorotate: function(galleryid) {
		var config = stepcarousel.configholder[galleryid]
		if (config.$gallery.attr('_ismouseover') != "yes") {
			this.stepBy(galleryid, config.autostep.moveby)
		}
		config.steptimer = setTimeout(function() { stepcarousel.autorotate(galleryid) }, config.autostep.pause)
	},

	statusreport: function(galleryid) {
		var config = stepcarousel.configholder[galleryid]
		var startpoint = config.currentpanel //index of first visible panel 
		var visiblewidth = 0
		for (var endpoint = startpoint; endpoint < config.paneloffsets.length; endpoint++) { //index (endpoint) of last visible panel
			visiblewidth += config.panelwidths[endpoint]
			if (visiblewidth > config.gallerywidth) {
				break
			}
		}
		startpoint += 1 //format startpoint for user friendiness
		endpoint = (endpoint + 1 == startpoint) ? startpoint : endpoint //If only one image visible on the screen and partially hidden, set endpoint to startpoint
		var valuearray = [startpoint, endpoint, config.panelwidths.length]
		for (var i = 0; i < config.statusvars.length; i++) {
			window[config.statusvars[i]] = valuearray[i] //Define variable (with user specified name) and set to one of the status values
			config.$statusobjs[i].text(valuearray[i] + " ") //Populate element on page with ID="user specified name" with one of the status values
		}
	},

	setup: function(config) {
		//Disable Step Gallery scrollbars ASAP dynamically (enabled for sake of users with JS disabled)
		//document.write('<style type="text/css">\n#' + config.galleryid + '{overflow: hidden;}\n</style>');
		jQuery(document).ready(function($) {
			config.$gallery = $('#' + config.galleryid)
			config.gallerywidth = config.$gallery.width()
			config.offsets = { left: stepcarousel.getoffset(config.$gallery.get(0), "offsetLeft"), top: stepcarousel.getoffset(config.$gallery.get(0), "offsetTop") }
			config.$belt = config.$gallery.find('.' + config.beltclass) //Find Belt DIV that contains all the panels
			config.$panels = config.$gallery.find('.' + config.panelclass) //Find Panel DIVs that each contain a slide
			config.panelbehavior.wraparound = (config.autostep && config.autostep.enable) ? true : config.panelbehavior.wraparound //if auto step enabled, set "wraparound" to true
			config.onpanelclick = (typeof config.onpanelclick == "undefined") ? function(target) { } : config.onpanelclick //attach custom "onpanelclick" event handler
			config.onslideaction = (typeof config.onslide == "undefined") ? function() { } : function(beltobj) { $(beltobj).stop(); config.onslide() } //attach custom "onslide" event handler
			config.oninit = (typeof config.oninit == "undefined") ? function() { } : config.oninit //attach custom "oninit" event handler
			config.beltoffset = stepcarousel.getCSSValue(config.$belt.css('marginLeft')) //Find length of Belt DIV's left margin
			config.statusvars = config.statusvars || []  //get variable names that will hold "start", "end", and "total" slides info
			config.$statusobjs = [$('#' + config.statusvars[0]), $('#' + config.statusvars[1]), $('#' + config.statusvars[2])]
			config.currentpanel = 0
			stepcarousel.configholder[config.galleryid] = config //store config parameter as a variable
			if (config.contenttype[0] == "ajax" && typeof config.contenttype[1] != "undefined") //fetch ajax content?
				stepcarousel.getremotepanels($, config)
			else
				stepcarousel.alignpanels($, config) //align panels and initialize gallery
		}) //end document.ready
		jQuery(window).bind('unload', function() { //clean up
			if (config.panelbehavior.persist) {
				stepcarousel.setCookie(window[config.galleryid + "persist"], config.currentpanel)
			}
			jQuery.each(config, function(ai, oi) {
				oi = null
			})
			config = null
		})
	}
}