/*
	Standards Compliant Rollover Script
	Author : Daniel Nolan
	http://www.bleedingego.co.uk/webdev.php

	Last Modified: Concent, Inc., 2008-07-01
	- new simple interface: call single function, options by a hash.
	  * not be lower-compatible!
*/

function setRollovers(opts) {

if (!opts) opts = {};
opts.rolloverClass               = opts.rolloverClass              || 'imgover';
opts.defaultRolloverImageSuffix  = opts.defaultRolloverImageSuffix || '_ov';

var targetImageIdSuffixRe = new RegExp('_' + opts.rolloverClass + '$'); // 'id_imgover'

setRolloversByTagName('img',   function(image) {return (true);                 });
setRolloversByTagName('input', function(input) {return (input.type == 'image');});

function setRolloversByTagName(targetTag, isRolloverObject) {
	var aImages = document.getElementsByTagName(targetTag); //like 'img', 'input',...
	for (var i = 0, n = aImages.length; i < n; i++) {
		var image = aImages[i];
		if (!image.className) continue;
		if (!getRolloverClass(image)) continue;
		if (!isRolloverObject(image)) continue;
		if (image.useMap) { // case of clickable map
			setRolloversClickableMap(image);
			continue; // next image
		}
		setRollover(image);
	}
}

function getRolloverClass(anObject) {
	var rolloverClassRe = new RegExp('^(' + opts.rolloverClass + ')(.*)');
	if (!anObject.className) return null;
	var classNames = anObject.className.split(' ');
	for (var i = 0, n = classNames.length; i < n; i++) {
		var classNameElements = classNames[i].match(rolloverClassRe);
		if (classNameElements) return classNameElements;
		// returns an array [class_full, class_base, class_extension]
	}
	return null;
}

function setRolloversClickableMap(image) {
	var mapId = image.useMap.match(/^\#(.*)/)[1]; // cut off the initial "#"
	var areas = document.getElementsByName(mapId).item(0).areas;
	for (var i = 0, n = areas.length; i < n; i++) {
		if (getRolloverClass(areas[i])) {
			setRollover(image, areas[i]);
		}
	}
}

function setRollover(targetImage, eventCaptureObject) {
	// if eventCaptureObject catch some mouseover/mouseout event,
	// then replace the image source of targetImage.
	var src = targetImage.src;
	var targetImageId = targetImage.getAttribute('id') || '';
	var eventCaptureId = (targetImageId.match(targetImageIdSuffixRe))
		? targetImageId.replace(targetImageIdSuffixRe, '')
		: '';

	eventCaptureObject
		= document.getElementById(eventCaptureId)
		|| eventCaptureObject
		|| targetImage;

	var rolloverImageSuffix = getRolloverClass(eventCaptureObject)[2] // _XX of imgover_XX
		|| opts.defaultRolloverImageSuffix;                       // _ov

	var ftype = src.substring(src.lastIndexOf('.'), src.length);
	var hsrc = src.replace(ftype, rolloverImageSuffix + ftype);
	var mouseoverImage = new Image();
	var mouseoutImage  = new Image();

	mouseoverImage.src = hsrc;	// preload mouseover image
	mouseoutImage.src  = src;	// save as mouseout image

	eventCaptureObject.onmouseover = function() {
		targetImage.src = hsrc;
	}

	eventCaptureObject.onmouseout = function() {
		targetImage.src = src;
	}
}
} // /setRollover