// global vertical menu state
var menubarReady = false;

// create hash table-like lookup for menu objects with id string indexes
function makeMenuBarHashes() {
    for (var i = 0; i < vmenus.length; i++) {
        vmenus[vmenus[i].elemId] = vmenus[i];
        vmenus[vmenus[i].mBarImgId] = vmenus[i];
    }
}

// assign menu label image event handlers
function assignMenuBarLabelEvents() {
    var elem;
    for (var i = 0; i < vmenus.length; i++) {
        elem = document.getElementById(vmenus[i].mBarImgId);
        elem.onmouseover = vswap;
        elem.onmouseout = vswap;
    }
}

// invoked from init(), generates the menu div elements and their contents.
// all this action is invisible to user during construction
function makeMenuBar() {
    var menuDiv, menuItem, itemLink, mbarImg, textNode, offsetLeft, offsetTop;
    
    // determine key adjustment factors for the total height of menu divs
    
    var menuItemH = 0;
    var bodyFontSize = parseInt(getElementStyle(document.body, "fontSize", "font-size"));
    // test to see if browser's font size has been adjusted by the user
    // and that the new size registers as an applied style property
    if (bodyFontSize == parseInt(CSSRuleValues.defaultBodyFontSize)) {
        menuItemH = (parseFloat(CSSRuleValues.menuItemHeight));
    } else {
        // works nicely in Netscape 7
        menuItemH = parseInt(parseFloat(CSSRuleValues.menuItemLineHeight) * bodyFontSize);
    }
    var heightAdjust = parseInt(CSSRuleValues.menuWrapperPadding) + 
        parseInt(CSSRuleValues.menuWrapperBorderWidth);
    if (navigator.appName == "Microsoft Internet Explorer" && 
        navigator.userAgent.indexOf("Win") != -1 && 
        (typeof document.compatMode == "undefined" || 
        document.compatMode == "BackCompat")) {
        heightAdjust = -heightAdjust;
    }
    
    // use menus array to drive div creation loop
    for (var i = 0; i < vmenus.length; i++) {
        menuDiv = document.createElement("div");
        menuDiv.id = "vpopupmenu" + i;
        // preserve menu's ID as property of the menus array item
        vmenus[i].elemId = "vpopupmenu" + i;
        menuDiv.className = "menubarWrapper";
        if (vmenus[i].menuItems.length > 0) {
            menuDiv.style.height = (menuItemH * vmenus[i].menuItems.length) - heightAdjust + "px";
        } else {
            // don't display any menu div lacking menu items
            menuDiv.style.display = "none";
        }
        // define event handlers
        menuDiv.onmouseover = keepMenuBar;
        menuDiv.onmouseout = requestMenuBarHide;

        // set stacking order in case other layers are around the page
        menuDiv.style.zIndex = 1000;
        
        // assemble menu item elements for inside menu div
        for (var j = 0; j < vmenus[i].menuItems.length; j++) {
            menuItem = document.createElement("div");
            menuItem.id = "vpopupmenuItem_" + i + "_" + j;
            menuItem.className = "menubarItem";
            menuItem.onmouseover = vtoggleHighlight;
            menuItem.onmouseout = vtoggleHighlight;
            menuItem.onclick = hideMenuBar;
            menuItem.style.top = menuItemH * j + "px";
            itemLink = document.createElement("a");
            itemLink.href = vmenus[i].menuItems[j].href;
            itemLink.className = "menubarItem";
            itemLink.onmouseover = vtoggleHighlight;
            itemLink.onmouseout = vtoggleHighlight;
            textNode = document.createTextNode(vmenus[i].menuItems[j].text);
            itemLink.appendChild(textNode);
            menuItem.appendChild(itemLink);
            menuDiv.appendChild(menuItem);
        }
        // append each menu div to the body
        document.body.appendChild(menuDiv);
    }
    makeMenuBarHashes();
    assignMenuBarLabelEvents();
    // pre-position menu
    for (i = 0; i < vmenus.length; i++) {
        positionMenuBar(vmenus[i].elemId);
    }
    menubarReady = true;
}

// initialize global that helps manage menu hiding
var menubarTimer;

// invoked from mouseovers inside menus to cancel hide
// request from mouseout of menu bar image et al.
function keepMenuBar() {
    clearTimeout(menubarTimer);
}

function vcancelAll() {
    keepMenuBar();
    menubarReady = false;
}

// invoked from mouseouts to request hiding all menus
// in 1/4 second, unless cancelled
function requestMenuBarHide() {
    menubarTimer = setTimeout("hideMenuBar()", 250);
}

// "brute force" hiding of all menus and restoration
// of normal menu bar images
function hideMenuBar() {
    for (var i = 0; i < vmenus.length; i++) {
       document.getElementById(vmenus[i].mBarImgId).className = "menuBar";
       var menu = document.getElementById(vmenus[i].elemId)
       menu.style.visibility = "hidden";
    }
}

// set menu position just before displaying it
function positionMenuBar(menuId){
    // use the menu bar image for position reference of related div
    var mBarImg = document.getElementById(vmenus[menuId].mBarImgId);
    var offsetTrail = mBarImg;
    var offsetLeft = 0;
    var offsetTop = 0;
    while (offsetTrail) {
        offsetLeft += offsetTrail.offsetLeft;
        offsetTop += offsetTrail.offsetTop;
        offsetTrail = offsetTrail.offsetParent;
    }
    if (navigator.userAgent.indexOf("Mac") != -1 && 
        typeof document.body.leftMargin != "undefined") {
        offsetLeft += document.body.leftMargin;
        offsetTop += document.body.topMargin;
    }
    var menuDiv = document.getElementById(menuId);
    menuDiv.style.top = offsetTop + "px";
	menuDiv.style.left = offsetLeft + parseInt(CSSRuleValues.menuItemWidth) + "px";
}

// display a particular menu div
function showMenuBar(menuId) {
    if (menubarReady) {
        keepMenuBar();
        hideMenuBar();
        positionMenuBar(menuId);
        var menu = document.getElementById(menuId);
        menu.style.visibility = "visible";
    }
}

// menu bar image swapping, invoked from mouse events in menu bar
// swap style sheets for menu items during rollovers
function vtoggleHighlight(evt) {
    evt = (evt) ? evt : ((event) ? event : null);
    if (typeof menubarReady != "undefined") {
        if (menubarReady && evt) {
            var elem = (evt.target) ? evt.target : evt.srcElement;
            if (elem.nodeType == 3) {
                elem = elem.parentNode;
            }
            if (evt.type == "mouseover") {
                keepMenuBar();
                elem.className ="menubarItemOn";
            } else {
                elem.className ="menubarItem";
                requestMenuBarHide();
            }
            evt.cancelBubble = true;
        }
    }
}

function vswap(evt) {
    evt = (evt) ? evt : ((event) ? event : null);
    if (typeof menubarReady != "undefined") {
        if (evt && (document.getElementById && document.styleSheets) && menubarReady) {
            var elem = (evt.target) ? evt.target : evt.srcElement;
			if (elem.className == "menuBar" || elem.className == "menuBarHilite") {
				if (elem.nodeName == "A") {
					elem = elem.parentNode;
				}
				if (evt.type == "mouseover") {
                    showMenuBar(vmenus[elem.id].elemId);
                    elem.className = "menuBarHilite";
                } else if (evt.type == "mouseout") {
                    requestMenuBarHide();
                }
                evt.cancelBubble = true;
            }
        }
    }
}

// create menus only if key items are supported
function initMenuBar() {
    if (document.getElementById && document.styleSheets) {
        setTimeout("makeMenuBar()", 5);
        window.onunload=vcancelAll;
    }
}