scroll-sneak.js

/*!
 * Scroll Sneak
 * http://mrcoles.com/scroll-sneak/
 *
 * Copyright 2010, Peter Coles
 * Licensed under the MIT licenses.
 * http://mrcoles.com/media/mit-license.txt
 *
 * Date: Mon Mar 8 10:00:00 2010 -0500
 */
var ScrollSneak = function(prefix, wait) {
    // clean up arguments (allows prefix to be optional - a bit of overkill)
    if (typeof(wait) == 'undefined' && prefix === true) prefix = null, wait = true;
    prefix = (typeof(prefix) == 'string' ? prefix : window.location.host).split('_').join('');
    var pre_name;

    // scroll function, if window.name matches, then scroll to that position and clean up window.name
    this.scroll = function() {
        if (window.name.search('^'+prefix+'_(\\d+)_(\\d+)_') == 0) {
            var name = window.name.split('_');
            window.scrollTo(name[1], name[2]);
            window.name = name.slice(3).join('_');
        }
    }
    // if not wait, scroll immediately
    if (!wait) this.scroll();

    this.sneak = function() {
    // prevent multiple clicks from getting stored on window.name
	if (typeof(pre_name) == 'undefined') pre_name = window.name;

	// get the scroll positions
        var top = 0, left = 0;
        if (typeof(window.pageYOffset) == 'number') { // netscape
            top = window.pageYOffset, left = window.pageXOffset;
        } else if (document.body && (document.body.scrollLeft || document.body.scrollTop)) { // dom
            top = document.body.scrollTop, left = document.body.scrollLeft;
        } else if (document.documentElement && (document.documentElement.scrollLeft || document.documentElement.scrollTop)) { // ie6
            top = document.documentElement.scrollTop, left = document.documentElement.scrollLeft;
        }
	// store the scroll
        if (top || left) window.name = prefix + '_' + left + '_' + top + '_' + pre_name;
        return true;
    }
}

// Example of applying sneak to a link:
/*
(function() {
    var sneaky = new ScrollSneak(location.hostname);
    document.getElementById('sneakytest').onclick = sneaky.sneak;
})();
 */