//
//
// Simple popup menu implementation:
//
//

var gActiveMenu = null;


function SimpleMenuBar(aMenuId, aOptions, aMenuItemList)
{
    var div = document.getElementById(aMenuId);

    this.mDiv = div;
    div._menu = this;

    this.mOptions = aOptions || new Object();

    // Grab any options for the menu...
    //
    //      "style" - CSS style to associate with each menu item
    //
    this.mStyle = this.mOptions["style"] || "menuitem";

    // Create the TABLE for the menu bar...
    var menuTable = document.createElement("TABLE");
    div.appendChild(menuTable);

    // Create the TBODY to contain the rows...
    var tbody = document.createElement("TBODY");
    menuTable.appendChild(tbody);

    // Create the TR for the menu bar...
    var row = document.createElement("TR");
    tbody.appendChild(row);

    // Create the TD for each menu item...
    for (var i=0; i<aMenuItemList.length; i++)
    {
        row.appendChild(this._newMenuItem(aMenuItemList[i]));

        // Create a vertical separating bar between each item.
        if (i < aMenuItemList.length-1)
        {
            var bar = document.createElement("TD");

            bar.className = this.mStyle;
            bar.appendChild(document.createTextNode("|"));
            row.appendChild(bar);
        }
    }
}

//
// Each menu item can have the following "properties":
//
//      "name"      - The menu item text.
//
//      "submenu"   - Id of the DIV corresponding to a SimpleMenuBar.  This
//                    menu is shown when the menu item is clicked.
//
//      "href"      - URL of a page to load when the menu item is clicked.
//
//      "selected"  - Indicates whether this menu item should be "selected"
//                    when the menu bar is first displayed.
//
SimpleMenuBar.prototype._newMenuItem = function(aInfo)
{
    if (typeof aInfo != "object")
    {
        aInfo = {name: "no name"};
    }
    // Create and initialize the TD representing the menu item.
    var menuitem = document.createElement("TD");
    menuitem.className = this.mStyle;

    var anchor = document.createElement("A");

    anchor.className = this.mStyle;
    anchor.href = "#";
    anchor.appendChild(document.createTextNode(aInfo["name"]));

    menuitem.appendChild(anchor);
//    item.textContent=aInfo["name"];

    // Handle "properties" for the menu item...
    if (aInfo["submenu"])
    {
        menuitem._submenu = aInfo["submenu"];
    }
    else if (aInfo["href"])
    {
        menuitem._href = aInfo["href"];
///        anchor.href = aInfo["href"];
        anchor.setAttribute("href", aInfo["href"]);
    }

    if (aInfo["selected"])
    {
        this._selectMenuItem(anchor);
    }

    var me = this;
    // Install event handlers...
    menuitem.onclick = function (aEvent)
    {
        // Select the menu item... This will deselect any previously selected
        // menu item.
        me._selectMenuItem(anchor);

        // Perform the menu item action...
        if (menuitem._submenu)
        {
            showSubMenu(menuitem._submenu)
        }
        else if (menuitem._href)
        {
            window.location.href = menuitem._href;
        }

        return false;
    }

    return menuitem;
}

SimpleMenuBar.prototype._selectMenuItem = function(aTarget)
{
    // Unselect any previously selected menu item...
    if (this._selected)
    {
        this._selected.className = 
            this._selected.className.replace(/_selected/, "");
    }
    this._selected = aTarget;

    // Select the new menu item...
    aTarget.className = aTarget.className + "_selected";
}

function showSubMenu(aPopupMenuId)
{
    // Find the DIV for the sub-menu...
    var menuDiv = document.getElementById(aPopupMenuId);

    if (gActiveMenu)
    {
        // Hide any previously visible sub-menu...
        gActiveMenu.style.visibility="hidden";
    }
    menuDiv.style.visibility="visible";
    gActiveMenu = menuDiv;

    // Get the SimpleMenuBar associated with the DIV...
    var menu = menuDiv._menu;

    // Select a menu item (if necessary)
    if (typeof menu._selected == "object")
    {
        var href = menu._selected.href;

        menu._selectMenuItem(menu._selected)
        if (href)
        {
            if (! isCurrentPage(href))
            {
                window.location.href = href;
            }
        }
    }
}


var gPreloadedImages = [];

function PreloadImages(aImageList)
{
    for (var i=0; i<aImageList.length; i++)
    {
        var img = aImageList[i];

        if (! gPreloadedImages[img]) 
        {
            gPreloadedImages[img] = new Image();
        }
        gPreloadedImages[img].src = img;
        
    }
}

//
// This deals with differences between anchor href attributes returned by
// IE verses other browsers...
//
// Basically, if the anchor href is relative (ie. it begins with a '.')
// then strip off the dot and see if the remaining string is completely
// contained with in the 'location.href' (which is guaranteed to be absolute).
//
// If the anchor href is already absolute, then the "substring" comparison
// should return 0.
//
function isCurrentPage(aHref)
{
    var page = window.location.href;
    var href = aHref;

    if (aHref.charAt(0) == '.')
    {
        href = aHref.replace(/^.\//, '');
    }
    
    return page.indexOf(href) != -1;
}