/* Javascript Galler Manager */
/* Copyright 2008 Mark Morgan, Raptor Studios Limited - http://www.raptor-studios.co.uk */

/* Ensure the following variables are provided on the **CALLING PAGE** */
/*

// The directory of the gallery
var imagePrepend = 'images/gallery/2008/20080503spa/';

// The extension type of the images
var imageExtension = '.jpg';

// The id of the large gallery image
var imageLargeID = 'galleryLarge';

// The width of the large image
var imageWidth = 675;

// The height of the large image
var imageHeight = 450;

// An Array of image names (without extensions)
var imgNames = [
				'001',
				'002',
				'003'
				];

*/


var currentImageIndex;
var totalNumberOfImages;

var preloadedImages;

/**
 *
 */
function DoPreload() {
	
	totalNumberOfImages = imgNames.length;
	
	preloadedImages = new Array(totalNumberOfImages);
	
	var i;
	for (i = 0; i < totalNumberOfImages; i++) {

		preloadedImages[i] = new Image(imageWidth, imageHeight);
		preloadedImages[i].src = imagePrepend + imgNames[i] + imageExtension;
		
	}
	
	currentImageIndex = 0;
}

/**
 *
 */
function ShowLarge(imageName) {
	
	var imageIndex = -1;
	
	var i;
	for (i = 0; i < totalNumberOfImages; i++) {
		
		if (imgNames[i] == imageName) {
			
			imageIndex = i;
			break;
			
		}
		
	}
	
	if (imageIndex != -1) {
		
		document[imageLargeID].src = preloadedImages[imageIndex].src;
		currentImageIndex = imageIndex;
		return false;
		
	}

}

/**
 *
 */
function NextImage() {

	var nextIndex = -1;
	
	if (currentImageIndex == (totalNumberOfImages - 1) ) {
		
		nextIndex = 0;
		
	} else {
		
		nextIndex = currentImageIndex + 1;
		
	}

	document[imageLargeID].src = preloadedImages[nextIndex].src;
	currentImageIndex = nextIndex;
	
	return false;
}

/**
 *
 */
function PreviousImage() {

	var nextIndex = -1;
	
	if (currentImageIndex == 0 ) {
		
		nextIndex = totalNumberOfImages - 1;
		
	} else {
		
		nextIndex = currentImageIndex - 1;
		
	}

	document[imageLargeID].src = preloadedImages[nextIndex].src;
	currentImageIndex = nextIndex;
	
	return false;
	
}