// ---
/*
	JaS is developed by Robert Nyman, http://www.robertnyman.com
	For more information, please see http://www.robertnyman.com/jas
*/
var JaS = {
	// Customization parameters
	imagePath : "pictures/",
	images : [
		["1.jpg", "Left to right - Tony Witt (Cook), Tony Durkin (Supplier), John Lawrence (AWM), John Usher (Teleg), Stan Hampson (AWM), Tony Giles (Cook), Martyn Spence (GWM), George Coulson (GWM), Bob Carmichael (AWM), Mike Seabrook(AWM), John Collins(AWM), George 'Mac' Macgregor(AWM), Bob Lewis (Cook)",],
		["2.jpg", "Group Photo  - Bob Lewis made the cake",],
		["3.jpg", "John Usher, Tony Witt and Bob Lewis",],
		["4.jpg", "John Collins, Mike Seabrook, Bob Carmichael, George 'Mac' Macgregor",],
		["5.jpg", "Martyn Spence, John Usher, Tony Giles, George 'Mac' Macgregor",],
		["6.jpg", "Tony Durkin the rest looking at the cake!", ],
		["7.jpg", "Bob Carmichael,Tony Giles,George Coulson,George Macgregor,Martyn Spence", ],
		["8.jpg", "Tony Giles speaking", ],
		["9.jpg", "Tony Giles speaking", ],
		["10.jpg", "John Collins, Mike Seabrook, Bob Carmichael, George 'Mac' Macgregor", ],
		["11.jpg", "Bob Carmichael, Mike Seabrook, Bob Lewis", ],
		["12.jpg", "Two Tony's and George", ],
		["13.jpg", "In the bar", ],
		["14.jpg", "Some of the Memorabilia", ],
		["15.jpg", "Some of the Memorabilia", ],
		["16.jpg", "BEAR 06 at Wolverhampton", ],
		["17.jpg", "BEAR 06 at Wolverhampton", ],
		["18.jpg", "BEAR 06 at Wolverhampton", ],
		["19.jpg", "BEAR 06 at Wolverhampton", ],
		["20.jpg", "BEAR 06 at Wolverhampton", ],
		["21.jpg", "BEAR 06 at Wolverhampton", ],
		["22.jpg", "Boy Entrant Memorial - The National Memorial Arboretum, Alrewas", ],
		["23.jpg", "Boy Entrant Memorial - The National Memorial Arboretum, Alrewas", ],
		["24.jpg", "Boy Entrant Memorial - The National Memorial Arboretum, Alrewas", ],
		["25.jpg", "29th Cosford Reunion - Group at Alrewas", ],
		["26.jpg", "John Usher and George 'Mac' Macgregor on the Beachat seat", ],
		["27.jpg", "John Usher and George 'Mac' Macgregor on the Beachat seat", ],
		["28.jpg", "Reunion Medal", ],
],
	fadeContainerId : "jas-container",
	imageContainerId : "jas-image",
	imageTextContainerId : "jas-image-text",
	previousLinkId : "previous-image",
	nextLinkId : "next-image",
	imageCounterId : "image-counter",
	startSlideShowId : "start-slideshow",
	stopSlideShowId : "stop-slideshow",	
	dimBackgroundOverlayId : "jas-dim-overlay",
	dimBackgroundId : "dim-background",
	noDimBackgroundId : "no-dim-background",
	thumbnailContainerId: "jas-thumbnails",
	tagsContainerId: "jas-tags",
	tagsSelectAllId: "jas-select-all-tags",
	useImageText : true,
	useThumbnails : true,
	allowDimmedBackground : true,
	automaticallyDimBackgroundWhenSlideShow : true,
	useTags : true,
	useKeyboardShortcuts : true,	
	useFadingIn : true,
	useFadingOut : true,
	useFadeWhenNotSlideshow : false,
	useFadeForSlideshow : true,
	useFadeAtInitialLoad : false,
	fadeIncrement : 0.1,	
	fadeInterval : 100, // Milliseconds	
	timeForSlideInSlideshow : 5000, // Milliseconds	
	
	// JaS function parameters
	allImages : null,
	currentImages : null,
	fadeContainer : null,
	imageContainer : null,
	imageTextContainer : null,
	previousLink : null,
	nextLink : null,
	dimBackgroundOverlay : null,
	dimBackgroundLink : null,
	noDimBackgroundLink : null,
	dimmingActivated : false,
	imageCounter : null,
	startSlideShowLink : null,
	stopSlideShowLink : null,
	thumbnailContainer : null,
	thumbnailCollection : [],
	currentThumbnailSelected : null,
	tagsContainer : null,
	tagsSelectAll : null,
	tagsList : null,
	tags : [],
	tagsCheckboxes : [],
	selectAllTags : true,
	imageText : null,
	imageText : "",
	imageSource : "",
	imageIndex : 0,
	fadingIn : true,
	fadeLevel : 0,
	fadeEndLevel : 1,
	fadeTimer : null,
	hasOpacitySupport : false,
	useMSFilter : false,
	useMSCurrentStyle : false,
	slideshowIsSupported : false,
	slideshowIsPlaying : false,
	functionAfterFade : null,
	isInitialLoad : false,
	
	init : function (){
    	if($){
			this.fadeContainer = $(this.fadeContainerId);
			this.imageContainer = $(this.imageContainerId);
			this.slideshowIsSupported = this.fadeContainer && this.imageContainer;
			if(this.slideshowIsSupported){
				this.allImages = this.images;
				this.currentImages = this.images;
				if(this.useImageText){
					this.imageTextContainer = $(this.imageTextContainerId);
					if(!this.imageTextContainer){
						this.useImageText = false;
					}
				}
				this.hasOpacitySupport = typeof this.fadeContainer.style.filter != "undefined" || typeof this.fadeContainer.style.opacity != "undefined";
				this.useMSFilter = typeof this.fadeContainer.style.filter != "undefined";
				this.useMSCurrentStyle = typeof this.fadeContainer.currentStyle != "undefined";
				
				this.previousLink = $(this.previousLinkId);
				this.previousLink.onclick = JaS.previousLinkClick;
				this.nextLink = $(this.nextLinkId);
				this.nextLink.onclick = JaS.nextLinkClick;
				this.imageCounter = $(this.imageCounterId);
				this.startSlideShowLink = $(this.startSlideShowId);
				if(this.startSlideShowLink){
					this.startSlideShowLink.style.display = "inline";
				}
				this.startSlideShowLink.onclick = JaS.startSlideShowClick;
				this.stopSlideShowLink = $(this.stopSlideShowId);
				if(this.stopSlideShowLink){
					this.stopSlideShowLink.style.display = "none";
				}
				this.stopSlideShowLink.onclick = JaS.stopSlideshowClick;
				
				if(this.allowDimmedBackground){
					this.dimBackgroundOverlay = $(this.dimBackgroundOverlayId);
					this.dimBackgroundLink = $(this.dimBackgroundId);
					this.noDimBackgroundLink = $(this.noDimBackgroundId);
					if(this.dimBackgroundOverlay && this.dimBackgroundLink && this.noDimBackgroundLink){
						this.dimBackgroundLink.onclick = JaS.dimBackgroundClick;
						this.noDimBackgroundLink.onclick = JaS.noDimackgroundClick;
						this.noDimBackgroundLink.style.display = "none";
						this.dimmingActivated = true;
					}
				}
				
				if(this.useKeyboardShortcuts){
					document.onkeydown = JaS.documentKeyDown;
				}
				
				this.thumbnailContainer = $(this.thumbnailContainerId);
				if(this.useThumbnails && this.thumbnailContainer){
					this.createThumbnails();
				}
				
				this.tagsContainer = $(this.tagsContainerId);
				if(this.useTags && this.tagsContainer){
					this.tagsSelectAll = $(this.tagsSelectAllId);
					if(this.tagsSelectAll){
						this.tagsSelectAll.onclick = JaS.tagsSelectAllClick;
						this.createTagList();
					}
				}
				
				this.isInitialLoad = true;
				this.setImage();
				this.isInitialLoad = false;
			}
		}
	},
	
	previousLinkClick : function(oEvent){
		var oEvent = (typeof oEvent != "undefined")? oEvent : event;
		JaS.preventDefaultEventBehavior(oEvent);
		JaS.previousImage();
	},
	
	nextLinkClick : function(oEvent){
		var oEvent = (typeof oEvent != "undefined")? oEvent : event;
		JaS.preventDefaultEventBehavior(oEvent);
		JaS.nextImage();
	},
	
	startSlideShowClick : function(oEvent){
		var oEvent = (typeof oEvent != "undefined")? oEvent : event;
		JaS.preventDefaultEventBehavior(oEvent);
		JaS.startSlideshow();
	},
	
	stopSlideshowClick : function(oEvent){
		var oEvent = (typeof oEvent != "undefined")? oEvent : event;
		JaS.preventDefaultEventBehavior(oEvent);
		JaS.stopSlideshow();
	},
	
	dimBackgroundClick : function(oEvent){
		var oEvent = (typeof oEvent != "undefined")? oEvent : event;
		JaS.preventDefaultEventBehavior(oEvent);
		JaS.dimBackground();
	},
	
	documentKeyDown : function(oEvent){
		var oEvent = (typeof oEvent != "undefined")? oEvent : event;
		JaS.applyKeyboardNavigation(oEvent);
	},
	
	tagsSelectAllClick : function (oEvent){
		JaS.tagsSelectAll = this.checked;
		JaS.markAllTags();
	},
	
	noDimackgroundClick : function(oEvent){
		var oEvent = (typeof oEvent != "undefined")? oEvent : event;
		JaS.preventDefaultEventBehavior(oEvent);
		JaS.noDimBackground();
	},
	
	setImage : function (){
		if(this.currentImages.length > 0){
			this.imageContainer.style.visibility = "visible";
			this.imageSource = this.currentImages[this.imageIndex][0];
			this.imageText = this.currentImages[this.imageIndex][1];
			if(this.useFadingOut && (this.slideshowIsPlaying && this.useFadeForSlideshow) || (!this.slideshowIsPlaying && this.useFadeWhenNotSlideshow) && (this.useFadeAtInitialLoad && this.isInitialLoad || !this.isInitialLoad)){
				this.fadeOut();
			}
			else{
				this.displayImageCount();
				this.imageContainer.setAttribute("src", (this.imagePath + this.imageSource));
				this.setImageText();
				this.previousLink.style.visibility = (this.imageIndex > 0)? "visible" : "hidden";
				this.nextLink.style.visibility = (this.imageIndex < (this.currentImages.length - 1))? "visible" : "hidden";
				if((this.useFadeAtInitialLoad && this.isInitialLoad || !this.isInitialLoad) && ((this.slideshowIsPlaying && this.useFadeForSlideshow) || (!this.slideshowIsPlaying && this.useFadeWhenNotSlideshow))){
					this.fadeIn();
				}
			}
			if(this.useThumbnails){
				this.markCurrentThumbnail();
			}
		}
		else{
			this.imageSource = "";
			this.imageText = "";
			this.displayImageCount();
			this.imageContainer.style.visibility = "hidden";
			this.setImageText();
		}
	},
	
	displayImageCount : function (){
    	if(this.imageCounter){
			this.imageCounter.innerHTML = (((this.currentImages.length > 0)? this.imageIndex : -1) + 1) + " / " + this.currentImages.length;
		}
	},
	
	nextImage : function (){
		if(this.imageIndex < (this.currentImages.length - 1)){
			++this.imageIndex;
			this.setImage();
		}
		else if(this.slideshowIsPlaying){
			this.stopSlideshow();
			this.imageIndex = 0;
			this.setImage();
		}
	},
	
	previousImage : function (){
		if(this.imageIndex > 0){
			--this.imageIndex;
			this.setImage();
		}         
	},

	setImageText : function (){
		this.imageTextContainer.setAttribute("alt", this.imageText);
    	if(this.useImageText && typeof this.imageText == "string"){
			this.imageTextContainer.innerHTML = this.imageText;
		}
	},
	
	setDimBackgroundSize : function(){
         var oDimBackground = this.dimBackgroundOverlay.style;
         var intWidth = document.body.offsetWidth;
         var intXScroll = (typeof window.pageXOffset != "undefined")? window.pageXOffset : document.body.scrollLeft;
         var intHeight = (typeof window.innerHeight != "undefined")? window.innerHeight : (document.documentElement)? document.documentElement.clientHeight : document.body.clientHeight;
         var intYScroll = (typeof window.window.pageYOffset != "undefined")? window.window.pageYOffset : (document.documentElement)? document.documentElement.scrollTop : document.documentElement.scrollTop;
         oDimBackground.width = intWidth + intXScroll + "px";
         oDimBackground.height = intHeight + intYScroll + "px";
	},
	
	dimBackground : function (){
         this.setDimBackgroundSize();
         this.dimBackgroundOverlay.style.display = "block";
		 this.noDimBackgroundLink.style.display = "inline";		
	},
	
	noDimBackground : function (fromStopSlideshow){
		this.dimBackgroundOverlay.style.display = "none";
		this.noDimBackgroundLink.style.display = "none";
		if(!fromStopSlideshow){
			this.stopSlideshow();
		}
	},
		
	startSlideshow : function (){
		if(this.currentImages.length > 0){
			this.startSlideShowLink.style.display = "none";
			this.stopSlideShowLink.style.display = "inline";
			this.slideshowIsPlaying = true;
			this.fadeTimer = setTimeout("JaS.nextImage()", JaS.timeForSlideInSlideshow);
			if(this.dimmingActivated  && this.automaticallyDimBackgroundWhenSlideShow){
				this.dimBackground();
			}
		}
	},
	
	stopSlideshow : function (){
		if(this.currentImages.length > 0){
			this.startSlideShowLink.style.display = "inline";
			this.stopSlideShowLink.style.display = "none";
			this.slideshowIsPlaying = false;
			this.setFadeParams(false, 1, 0);
			this.setFade();
			clearTimeout(this.fadeTimer);
			if(this.dimmingActivated && this.automaticallyDimBackgroundWhenSlideShow){
				this.noDimBackground(true);
			}
		}
	},
	
	fadeIn : function (){
		this.setFadeParams(true, 0, 1);
		this.functionAfterFade = null;
		this.fade();
		if(this.slideshowIsPlaying){
			this.functionAfterFade = "this.startSlideshow()";
		}
	},
	
	fadeOut : function (){
		this.setFadeParams(false, 1, 0);
		this.functionAfterFade = "this.fadeOutDone()";
		this.fade();
	},
	
	fadeOutDone : function (){
        this.displayImageCount();
		this.imageContainer.setAttribute("src", (this.imagePath + this.imageSource));
		this.setImageText();
		if(this.useFadingIn){
			this.fadeIn();
		}
		else{
			this.fadeLevel = 1;
			this.setFade();
		}
	},
	
	fade : function (){
		if((this.fadingIn && this.fadeLevel < this.fadeEndLevel) || !this.fadingIn && this.fadeLevel > this.fadeEndLevel){
			this.fadeLevel = (this.fadingIn)? this.fadeLevel + this.fadeIncrement : this.fadeLevel - this.fadeIncrement;
			// This line is b/c of a floating point bug in JavaScript
			this.fadeLevel = Math.round(this.fadeLevel * 10) / 10;
			this.setFade();
			this.fadeTimer = setTimeout("JaS.fade()", this.fadeInterval);
		}
		else{
			clearTimeout(this.fadeTimer);
			if(this.functionAfterFade){
				eval(this.functionAfterFade);
			}
		}
	},
	
	setFade : function (){
		if(this.useMSFilter){
			this.fadeContainer.style.filter = "progid:DXImageTransform.Microsoft.Alpha(opacity=" + (this.fadeLevel * 100) + ")";
		}
		else{
			this.fadeContainer.style.opacity = this.fadeLevel;
		}
	},
	
	setFadeParams : function (bFadingIn, intStartLevel, intEndLevel){
		this.fadingIn = bFadingIn;
		this.fadeLevel = intStartLevel;
		this.fadeEndLevel = intEndLevel;
	},
	
	createThumbnails : function (){
		this.thumbnailContainer.innerHTML = "";
		this.thumbnailCollection = [];
    	var oThumbnailsList = document.createElement("ul");
		var oListItem;
		var oThumbnail;
		var oCurrentImage;
		for(var i=0; i<this.currentImages.length; i++){
        	oCurrentImage = this.currentImages[i];
			oListItem = document.createElement("li");
			oThumbnail = document.createElement("img");
			oThumbnail.setAttribute("id", ("jas-thumbnail-" + i));
			oThumbnail.setAttribute("src", (this.imagePath + oCurrentImage[0]));
			oThumbnail.setAttribute("alt", oCurrentImage[1]);
			oThumbnail.setAttribute("title", oCurrentImage[1]);
			oThumbnail.onclick = JaS.thumbnailClick;
			this.thumbnailCollection.push(oThumbnail);
			oListItem.appendChild(oThumbnail);
			oThumbnailsList.appendChild(oListItem);			
        }
		this.thumbnailContainer.appendChild(oThumbnailsList);
		if(this.thumbnailCollection.length > 0){
			this.markCurrentThumbnail();
		}
		if(this.slideshowIsPlaying){
			this.stopSlideshow();
		}
	},
	
	thumbnailClick : function (oEvent){
		JaS.imageIndex = parseInt(this.getAttribute("id").replace(/\D*(\d+)$/, "$1"), 10);
		JaS.setImage();
	},
	
	markCurrentThumbnail : function (){
		if(this.currentThumbnailSelected){
	        this.currentThumbnailSelected.className = "";
			// Sometimes, in IE, the image loses its reference to its parent
			if(this.currentThumbnailSelected.parentNode){
				this.currentThumbnailSelected.parentNode.className = "";
			}
		}
		this.currentThumbnailSelected = this.thumbnailCollection[this.imageIndex];
		this.currentThumbnailSelected.className = "selected";
		this.currentThumbnailSelected.parentNode.className = "selected-parent";
	},
	
	createTagList : function (){
		var strCurrentTag;
		var arrCurrentTag;
		var oRegExp;
		for(var i=0; i<this.images.length; i++){
			arrCurrentTag = this.images[i][2].replace(/\s*(,)\s*/,  "$1").split(",");
			for(var j=0; j<arrCurrentTag.length; j++){
            	strCurrentTag = arrCurrentTag[j];
				oRegExp = new RegExp(strCurrentTag, "i");
				if(this.tags.toString().search(oRegExp) == -1){
					this.tags.push(strCurrentTag);
				}
            }
        }
		this.tagsList = document.createElement("ul");
		var oListItem;
		var oTagCheckbox;
		var oLabel;
		for(var k=0; k<this.tags.length; k++){
			oTag = this.tags[k];
			oListItem = document.createElement("li");
			oTagCheckbox = document.createElement("input");
			oTagCheckbox.setAttribute("type", "checkbox");
			oTagCheckbox.setAttribute("id", ("jas-" + oTag));
			oTagCheckbox.setAttribute("value", oTag);
			oTagCheckbox.checked = true;
			oTagCheckbox.onclick = JaS.tagCheckboxClick;
			oLabel = document.createElement("label");
			oLabel.setAttribute("for", ("jas-" + oTag));
			oLabel.innerHTML = oTag;
			this.tagsCheckboxes.push(oTagCheckbox);
			oListItem.appendChild(oTagCheckbox);
			oListItem.appendChild(oLabel);
			this.tagsList.appendChild(oListItem);
		}
		this.tagsContainer.appendChild(this.tagsList);
		// This loop is necessary since IE can only mark checkboxes as checked after they've been added to the document
		for(var l=0; l<this.tagsCheckboxes.length; l++){
			this.tagsCheckboxes[l].checked = true;		
		}
	},
	
	tagCheckboxClick : function (oEvent){
		JaS.applyTagFilter();
	},
	
	applyTagFilter : function (){
		this.currentImages = [];
		var arrCurrentTags = [];
		var oCheckbox;
		for(var i=0; i<this.tagsCheckboxes.length; i++){
        	oCheckbox = this.tagsCheckboxes[i];
			if(oCheckbox.checked){
				arrCurrentTags.push(oCheckbox.value);
			}
        }
		var oRegExp;
		var oImage;
		for(var j=0; j<this.images.length; j++){
        	oImage = this.images[j];
			for(var k=0; k<arrCurrentTags.length; k++){
				oRegExp = new RegExp(arrCurrentTags[k], "i");
				if(oImage[2].search(oRegExp) != -1){
					this.currentImages.push(oImage);
					break;
				}
			}
        }
		
		if(this.useThumbnails){
			this.createThumbnails();
		}
		this.imageIndex = 0;
		this.setImage();
	},
	
	markAllTags : function (){
		for(var i=0; i<this.tagsCheckboxes.length; i++){
			this.tagsCheckboxes[i].checked = this.tagsSelectAll;
        }
		this.applyTagFilter();
	},
	
	closeSession : function (oEvent){
		JaS = null;
		delete JaS;
	},
	
	applyKeyboardNavigation : function (oEvent){
    	var intKeyCode = oEvent.keyCode;
    	if(!oEvent.altKey){
			switch(intKeyCode){
				case 32:
					this.slideshowIsPlaying = (this.slideshowIsPlaying)? false : true;
					if(this.slideshowIsPlaying){
						this.startSlideshow();
					}
					else{
						this.stopSlideshow();
					}
					this.preventDefaultEventBehavior(oEvent);
					break;
				case 37:
				case 38:
					this.previousImage();
					this.preventDefaultEventBehavior(oEvent);
					break;
				case 39:
				case 40:
					this.nextImage();
					this.preventDefaultEventBehavior(oEvent);
					break;
			}
		}
	},
	
	preventDefaultEventBehavior : function (oEvent){
		if(oEvent){
			oEvent.returnValue = false;
			if(oEvent.preventDefault){
				oEvent.preventDefault();
			}
		}
	}
};
// ---
addEvent(window, "load", function(){JaS.init();}, false);
addEvent(window, "unload", function(){JaS.closeSession();}, false);
// ---
// Utility functions
function addEvent(oObject, strEvent, oFunction, bCapture){
	if(oObject){
		if(oObject.addEventListener){
			oObject.addEventListener(strEvent, oFunction, bCapture);
		}
		else if(window.attachEvent){
			oObject.attachEvent(("on" + strEvent), oFunction)
		}
	}
}
// ---
function $(strId){
	return document.getElementById(strId);
}
// ---
if(typeof Array.prototype.push != "function"){
	Array.prototype.push = ArrayPush;
	function ArrayPush(value){
		this[this.length] = value;
	}
}
// ---
