// Author: Dietmar Rabich, lewiser
// Date: 2003-02-13
// Description: A generic script for highlighting links with rollover images.
// If the image points to the current page, it stays highlighted.
// The image within the link must have the same name as the two
// images, and these must be called "....gif" and "../../www.expo-archive.ch_high.gif"
// or "....jpg" and "../../www.expo-archive.ch_high.jpg".
// This script also fully supports language suffixes.
// Usage:
// load_images ( Pre-loads an image's two versions when the page has loaded. Call this in .
// name The name of the image object. This is the same as in ![]()
// filename The filename of the image file. The highlighted version must end in "_high.gif".
// file_suffix The file suffix of the image file. If none is specified, "gif" is the default.
// )
//
// show_image ( Shows the highlighted version of the image.
// name The name of the image object. This is the same as in ![]()
// )
// Returns:
// showStatus The status of the highlighting, which must be "true", otherwise JavaScript chokes.
//
// hide_image ( Shows the normal version of the image.
// name The name of the image object. This is the same as in ![]()
// )
//
// select_active_image ( This checks what links points to the current URL. The correspondant image is then highlighted. Call this in .
// )
//
// doc_image ( Creates an image object from a file. This is only used internally, so don't use it.
// filename The filename of the image file.
// )
// Returns:
// image The JavaScript image object containing the two images.
//
// Original: http://www.rabich.de
// HTML usage:
//
//
//
//
// 
//
// Create the image array
var Img = new Array();
// Create the image object
// Note that for files with suffixes, we insert the '_high' part before the first suffix,
// which is indicated by the first '-'.
function doc_image(filename, file_suffix) {
this.normal = new Image();
this.high = new Image();
var suffixIndex = filename.indexOf('-');
if (suffixIndex > -1) {
this.normal.src = filename + "." + file_suffix;
this.high.src = filename.substring(0, suffixIndex) + "_high" + filename.substring(suffixIndex) + "." + file_suffix;
} else {
this.normal.src = filename + "." + file_suffix;
this.high.src = filename + "_high." + file_suffix;
}
return this;
}
// Create the image information
function load_images(name, filename, file_suffix) {
if (file_suffix == null || file_suffix == "") {
file_suffix = "gif";
}
Img[name] = new doc_image(filename, file_suffix);
}
// Show the image
function show_image(name) {
document[name].src = Img[name].high.src;
return true;
}
// Hide the image, but only if it's not the image of the current page
function hide_image(name) {
var currentPage;
currentPage = document.URL;
currentPage = currentPage.substring(currentPage.lastIndexOf("/")+1);
if (name != currentPage.substr(0,name.length)) {
document[name].src = Img[name].normal.src;
}
}
// Select the active image, depending on the page's file name.
function select_active_image () {
var i;
var currentPage;
var keyLength;
currentPage = document.URL;
currentPage = currentPage.substring(currentPage.lastIndexOf("/")+1);
for (i in Img) {
keyLength = i.length;
if (i == currentPage.substr(0,keyLength)) {
document[i].src = Img[i].high.src;
}
}
}