path: root/comm/suite/chatzilla/js/lib/menu-manager.js

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

//
function MenuManager(commandManager, menuSpecs, contextFunction, commandStr)
{
    var menuManager = this;

    this.commandManager = commandManager;
    this.menuSpecs = menuSpecs;
    this.contextFunction = contextFunction;
    this.commandStr = commandStr;
    this.repeatId = 0;
    this.cxStore = new Object();

    this.onPopupShowing =
        function mmgr_onshow(event) { return menuManager.showPopup(event); };
    this.onPopupHiding =
        function mmgr_onhide(event) { return menuManager.hidePopup(event); };
    this.onMenuCommand =
        function mmgr_oncmd(event) { return menuManager.menuCommand(event); };

    /* The code using us may override these with functions which will be called
     * after all our internal processing is done. Both are called with the
     * arguments 'event' (DOM), 'cx' (JS), 'popup' (DOM).
     */
    this.onCallbackPopupShowing = null;
    this.onCallbackPopupHiding = null;
}

MenuManager.prototype.appendMenuItems =
function mmgr_append(menuId, items)
{
    for (var i = 0; i < items.length; ++i)
        this.menuSpecs[menuId].items.push(items[i]);
}

MenuManager.prototype.createContextMenus =
function mmgr_initcxs (document)
{
    for (var id in this.menuSpecs)
    {
        if (id.indexOf("context:") == 0)
            this.createContextMenu(document, id);
    }
}

MenuManager.prototype.createContextMenu =
function mmgr_initcx (document, id)
{
    if (!document.getElementById(id))
    {
        if (!ASSERT(id in this.menuSpecs, "unknown context menu " + id))
            return;

        var dp = document.getElementById("dynamic-popups");
        var popup = this.appendPopupMenu (dp, null, id, id);
        var items = this.menuSpecs[id].items;
        this.createMenuItems (popup, null, items);

        if (!("uiElements" in this.menuSpecs[id]))
            this.menuSpecs[id].uiElements = [popup];
        else if (!arrayContains(this.menuSpecs[id].uiElements, popup))
            this.menuSpecs[id].uiElements.push(popup);
    }
}


MenuManager.prototype.createMenus =
function mmgr_createtb(document, menuid)
{
    var menu = document.getElementById(menuid);
    for (var id in this.menuSpecs)
    {
        var domID;
        if ("domID" in this.menuSpecs[id])
            domID = this.menuSpecs[id].domID;
        else
            domID = id;

        if (id.indexOf(menuid + ":") == 0)
            this.createMenu(menu, null, id, domID);
    }
}

MenuManager.prototype.createMainToolbar =
function mmgr_createtb(document, id)
{
    var toolbar = document.getElementById(id);
    var spec = this.menuSpecs[id];
    for (var i in spec.items)
    {
        this.appendToolbarItem (toolbar, null, spec.items[i]);
    }

    toolbar.className = "toolbar-primary chromeclass-toolbar";
}

MenuManager.prototype.updateMenus =
function mmgr_updatemenus(document, menus)
{
    // Cope with one string (update just the one menu)...
    if (isinstance(menus, String))
    {
        menus = [menus];
    }
    // Or nothing/nonsense (update everything).
    else if ((typeof menus != "object") || !isinstance(menus, Array))
    {
        menus = [];
        for (var k in this.menuSpecs)
        {
            if ((/^(mainmenu|context)/).test(k))
                menus.push(k);
        }
    }

    var menuBar = document.getElementById("mainmenu");

    // Loop through this array and update everything we need to.
    for (var i = 0; i < menus.length; i++)
    {
        var id = menus[i];
        if (!(id in this.menuSpecs))
            continue;
        var menu = this.menuSpecs[id];
        var domID;
        if ("domID" in this.menuSpecs[id])
            domID = this.menuSpecs[id].domID;
        else
            domID = id;

        // Context menus need to be deleted in order to be regenerated...
        if ((/^context/).test(id))
        {
            var cxMenuNode;
            if ((cxMenuNode = document.getElementById(id)))
                cxMenuNode.parentNode.removeChild(cxMenuNode);
            this.createContextMenu(document, id);
        }
        else if ((/^mainmenu/).test(id) &&
                 !("uiElements" in this.menuSpecs[id]))
        {
            this.createMenu(menuBar, null, id, domID);
            continue;
        }
        else if ((/^(mainmenu|popup)/).test(id) &&
                 ("uiElements" in this.menuSpecs[id]))
        {
            for (var j = 0; j < menu.uiElements.length; j++)
            {
                var node = menu.uiElements[j];
                domID = node.parentNode.id;
                // Clear the menu node.
                while (node.lastChild)
                    node.removeChild(node.lastChild);

                this.createMenu(node.parentNode.parentNode,
                                node.parentNode.nextSibling,
                                id, domID);
            }
        }
        
        
    }
}


/**
 * Internal use only.
 *
 * Registers event handlers on a given menu.
 */
MenuManager.prototype.hookPopup =
function mmgr_hookpop (node)
{
    node.addEventListener ("popupshowing", this.onPopupShowing, false);
    node.addEventListener ("popuphiding",  this.onPopupHiding, false);
}

/**
 * Internal use only.
 *
 * |showPopup| is called from the "onpopupshowing" event of menus managed
 * by the CommandManager. If a command is disabled, represents a command
 * that cannot be "satisfied" by the current command context |cx|, or has an
 * "enabledif" attribute that eval()s to false, then the menuitem is disabled.
 * In addition "checkedif" and "visibleif" attributes are eval()d and
 * acted upon accordingly.
 */
MenuManager.prototype.showPopup =
function mmgr_showpop (event)
{
    /* returns true if the command context has the properties required to
     * execute the command associated with |menuitem|.
     */
    function satisfied()
    {
        if (menuitem.hasAttribute("isSeparator") ||
            !menuitem.hasAttribute("commandname"))
        {
            return true;
        }

        if (menuitem.hasAttribute("repeatfor"))
            return false;

        if (!("menuManager" in cx))
        {
            dd ("no menuManager in cx");
            return false;
        }

        var name = menuitem.getAttribute("commandname");
        var commandManager = cx.menuManager.commandManager;
        var commands = commandManager.commands;

        if (!ASSERT (name in commands,
                     "menu contains unknown command '" + name + "'"))
        {
            return false;
        }

        var rv = commandManager.isCommandSatisfied(cx, commands[name]);
        delete cx.parseError;
        return rv;
    };

    /* Convenience function for "enabledif", etc, attributes. */
    function has (prop)
    {
        return (prop in cx);
    };

    /* evals the attribute named |attr| on the node |node|. */
    function evalIfAttribute (node, attr)
    {
        var ex;
        var expr = node.getAttribute(attr);
        if (!expr)
            return true;

        expr = expr.replace (/\Wand\W/gi, " && ");
        expr = expr.replace (/\Wor\W/gi, " || ");

        try
        {
            return eval("(" + expr + ")");
        }
        catch (ex)
        {
            dd ("caught exception evaling '" + node.getAttribute("id") + "'.'" +
                attr + "': '" + expr + "'\n" + ex);
        }
        return true;
    };

    /* evals the attribute named |attr| on the node |node|. */
    function evalAttribute(node, attr)
    {
        var ex;
        var expr = node.getAttribute(attr);
        if (!expr)
            return null;

        try
        {
            return eval(expr);
        }
        catch (ex)
        {
            dd ("caught exception evaling '" + node.getAttribute("id") + "'.'" +
                attr + "': '" + expr + "'\n" + ex);
        }
        return null;
    };

    var cx;
    var popup = event.originalTarget;
    var menuName = popup.getAttribute("menuName");

    /* If the host provided a |contextFunction|, use it now.  Remember the
     * return result as this.cx for use if something from this menu is actually
     * dispatched.  */
    if (typeof this.contextFunction == "function")
    {
        cx = this.cx = this.contextFunction(menuName, event);
    }
    else
    {
        cx = this.cx = { menuManager: this, originalEvent: event };
    }

    // Keep the context around by menu name. Removed in hidePopup.
    this.cxStore[menuName] = cx;

    var menuitem = popup.firstChild;
    do
    {
        if (!menuitem.hasAttribute("repeatfor"))
            continue;

        // Remove auto-generated items (located prior to real item).
        while (menuitem.previousSibling &&
               menuitem.previousSibling.hasAttribute("repeatgenerated"))
        {
            menuitem.parentNode.removeChild(menuitem.previousSibling);
        }

        if (!("repeatList" in cx))
            cx.repeatList = new Object();

        /* Get the array of new items to add by evaluating "repeatfor" with
         * "cx" in scope. Usually will return an already-calculated Array
         * either from "cx" or somewhere in the object model.
         */
        var ary = evalAttribute(menuitem, "repeatfor");

        if ((typeof ary != "object") || !isinstance(ary, Array))
            ary = [];

        /* The item itself should only be shown if there's no items in the
         * array - this base item is always disabled.
         */
        if (ary.length > 0)
            menuitem.setAttribute("hidden", "true");
        else
            menuitem.removeAttribute("hidden");

        // Save the array in the context object.
        cx.repeatList[menuitem.getAttribute("repeatid")] = ary;

        /* Get the maximum number of items we're allowed to show from |ary| by
         * evaluating "repeatlimit" with "cx" in scope. This could be a fixed
         * limit or dynamically calculated (e.g. from prefs).
         */
        var limit = evalAttribute(menuitem, "repeatlimit");
        // Make sure we've got a number at all...
        if (typeof limit != "number")
            limit = ary.length;
        // ...and make sure it's no higher than |ary.length|.
        limit = Math.min(ary.length, limit);

        var cmd = menuitem.getAttribute("commandname");
        var props = { repeatgenerated: true, repeatindex: -1,
                      repeatid: menuitem.getAttribute("repeatid"),
                      repeatmap: menuitem.getAttribute("repeatmap") };

        /* Clone non-repeat attributes. All attributes except those starting
         * with 'repeat', and those matching 'hidden' or 'disabled' are saved
         * to |props|, which is then supplied to |appendMenuItem| later.
         */
        for (var i = 0; i < menuitem.attributes.length; i++)
        {
            var name = menuitem.attributes[i].nodeName;
            if (!name.match(/^(repeat|(hidden|disabled)$)/))
                props[name] = menuitem.getAttribute(name);
        }

        var lastGroup = "";
        for (i = 0; i < limit; i++)
        {
            /* Check for groupings. For each item we add, if "repeatgroup" gives
             * a different value, we insert a separator.
             */
            if (menuitem.getAttribute("repeatgroup"))
            {
                cx.index = i;
                ary = cx.repeatList[menuitem.getAttribute("repeatid")];
                var item = ary[i];
                /* Apply any updates to "cx" for this item by evaluating
                 * "repeatmap" with "cx" and "item" in scope. This may just
                 * copy some attributes from "item" to "cx" or it may do more.
                 */
                evalAttribute(menuitem, "repeatmap");
                /* Get the item's group by evaluating "repeatgroup" with "cx"
                 * and "item" in scope. Usually will return an appropriate
                 * property from "item".
                 */
                var group = evalAttribute(menuitem, "repeatgroup");

                if ((i > 0) && (lastGroup != group))
                    this.appendMenuSeparator(popup, menuitem, props);

                lastGroup = group;
            }

            props.repeatindex = i;
            this.appendMenuItem(popup, menuitem, cmd, props);
        }
    } while ((menuitem = menuitem.nextSibling));

    menuitem = popup.firstChild;
    do
    {
        if (menuitem.hasAttribute("repeatgenerated") &&
            menuitem.hasAttribute("repeatmap"))
        {
            cx.index = menuitem.getAttribute("repeatindex");
            ary = cx.repeatList[menuitem.getAttribute("repeatid")];
            var item = ary[cx.index];
            /* Apply any updates to "cx" for this item by evaluating
             * "repeatmap" with "cx" and "item" in scope. This may just
             * copy some attributes from "item" to "cx" or it may do more.
             */
            evalAttribute(menuitem, "repeatmap");
        }

        /* should it be visible? */
        if (menuitem.hasAttribute("visibleif"))
        {
            if (evalIfAttribute(menuitem, "visibleif"))
                menuitem.removeAttribute ("hidden");
            else
            {
                menuitem.setAttribute ("hidden", "true");
                continue;
            }
        }

        /* it's visible, maybe it has a dynamic label? */
        if (menuitem.hasAttribute("format"))
        {
            var label = replaceVars(menuitem.getAttribute("format"), cx);
            if (label.indexOf("\$") != -1)
                label = menuitem.getAttribute("backupLabel");
            menuitem.setAttribute("label", label);
        }

        /* ok, it's visible, maybe it should be disabled? */
        if (satisfied())
        {
            if (menuitem.hasAttribute("enabledif"))
            {
                if (evalIfAttribute(menuitem, "enabledif"))
                    menuitem.removeAttribute ("disabled");
                else
                    menuitem.setAttribute ("disabled", "true");
            }
            else
                menuitem.removeAttribute ("disabled");
        }
        else
        {
            menuitem.setAttribute ("disabled", "true");
        }

        /* should it have a check? */
        if (menuitem.hasAttribute("checkedif"))
        {
            if (evalIfAttribute(menuitem, "checkedif"))
                menuitem.setAttribute ("checked", "true");
            else
                menuitem.removeAttribute ("checked");
        }
    } while ((menuitem = menuitem.nextSibling));

    if (typeof this.onCallbackPopupShowing == "function")
        this.onCallbackPopupShowing(event, cx, popup);

    return true;
}

/**
 * Internal use only.
 *
 * |hidePopup| is called from the "onpopuphiding" event of menus
 * managed by the CommandManager.  Clean up this.cxStore, but
 * not this.cx because that messes up nested menus.
 */
MenuManager.prototype.hidePopup =
function mmgr_hidepop(event)
{
    var popup = event.originalTarget;
    var menuName = popup.getAttribute("menuName");

    if (typeof this.onCallbackPopupHiding == "function")
        this.onCallbackPopupHiding(event, this.cxStore[menuName], popup);

    delete this.cxStore[menuName];

    return true;
}

MenuManager.prototype.menuCommand =
function mmgr_menucmd(event)
{
    /* evals the attribute named |attr| on the node |node|. */
    function evalAttribute(node, attr)
    {
        var ex;
        var expr = node.getAttribute(attr);
        if (!expr)
            return null;

        try
        {
            return eval(expr);
        }
        catch (ex)
        {
            dd ("caught exception evaling '" + node.getAttribute("id") + "'.'" +
                attr + "': '" + expr + "'\n" + ex);
        }
        return null;
    };

    var menuitem = event.originalTarget;
    var cx = this.cx;
    /* We need to re-run the repeat-map if the user has selected a special
     * repeat-generated menu item, so that the context object is correct.
     */
    if (menuitem.hasAttribute("repeatgenerated") &&
        menuitem.hasAttribute("repeatmap"))
    {
        cx.index = menuitem.getAttribute("repeatindex");
        var ary = cx.repeatList[menuitem.getAttribute("repeatid")];
        var item = ary[cx.index];
        /* Apply any updates to "cx" for this item by evaluating
         * "repeatmap" with "cx" and "item" in scope. This may just
         * copy some attributes from "item" to "cx" or it may do more.
         */
        evalAttribute(menuitem, "repeatmap");
    }

    eval(this.commandStr);
};


/**
 * Appends a sub-menu to an existing menu.
 * @param parentNode  DOM Node to insert into
 * @param beforeNode  DOM Node already contained by parentNode, to insert before
 * @param domId       ID of the sub-menu to add.
 * @param label       Text to use for this sub-menu.
 * @param accesskey   Accesskey to use for the sub-menu.
 * @param attribs     Object containing CSS attributes to set on the element.
 */
MenuManager.prototype.appendSubMenu =
function mmgr_addsmenu(parentNode, beforeNode, menuName, domId, label,
                       accesskey, attribs)
{
    var document = parentNode.ownerDocument;

    /* sometimes the menu is already there, for overlay purposes. */
    var menu = document.getElementById(domId);

    if (!menu)
    {
        menu = document.createElement ("menu");
        menu.setAttribute ("id", domId);
    }

    var menupopup = menu.firstChild;

    if (!menupopup)
    {
        menupopup = document.createElement ("menupopup");
        menupopup.setAttribute ("id", domId + "-popup");
        menu.appendChild(menupopup);
        menupopup = menu.firstChild;
    }

    menupopup.setAttribute ("menuName", menuName);

    menu.setAttribute("accesskey", accesskey);
    label = label.replace("&", "");
    menu.setAttribute ("label", label);
    menu.setAttribute ("isSeparator", true);

    // Only attach the menu if it's not there already. This can't be in the
    // if (!menu) block because the updateMenus code clears toplevel menus,
    // orphaning the submenus, to (parts of?) which we keep handles in the
    // uiElements array. See the updateMenus code.
    if (!menu.parentNode)
        parentNode.insertBefore(menu, beforeNode);

    if (typeof attribs == "object")
    {
        for (var p in attribs)
            menu.setAttribute (p, attribs[p]);
    }

    this.hookPopup (menupopup);

    return menupopup;
}

/**
 * Appends a popup to an existing popupset.
 * @param parentNode  DOM Node to insert into
 * @param beforeNode  DOM Node already contained by parentNode, to insert before
 * @param id      ID of the popup to add.
 * @param label   Text to use for this popup.  Popup menus don't normally have
 *                labels, but we set a "label" attribute anyway, in case
 *                the host wants it for some reason.  Any "&" characters will
 *                be stripped.
 * @param attribs Object containing CSS attributes to set on the element.
 */
MenuManager.prototype.appendPopupMenu =
function mmgr_addpmenu (parentNode, beforeNode, menuName, id, label, attribs)
{
    var document = parentNode.ownerDocument;
    var popup = document.createElement ("menupopup");
    popup.setAttribute ("id", id);
    if (label)
        popup.setAttribute ("label", label.replace("&", ""));
    if (typeof attribs == "object")
    {
        for (var p in attribs)
            popup.setAttribute (p, attribs[p]);
    }

    popup.setAttribute ("menuName", menuName);

    parentNode.insertBefore(popup, beforeNode);
    this.hookPopup (popup);

    return popup;
}

/**
 * Appends a menuitem to an existing menu or popup.
 * @param parentNode  DOM Node to insert into
 * @param beforeNode  DOM Node already contained by parentNode, to insert before
 * @param command A reference to the CommandRecord this menu item will represent.
 * @param attribs Object containing CSS attributes to set on the element.
 */
MenuManager.prototype.appendMenuItem =
function mmgr_addmenu (parentNode, beforeNode, commandName, attribs)
{
    var menuManager = this;

    var document = parentNode.ownerDocument;
    if (commandName == "-")
        return this.appendMenuSeparator(parentNode, beforeNode, attribs);

    var parentId = parentNode.getAttribute("id");

    if (!ASSERT(commandName in this.commandManager.commands,
                "unknown command " + commandName + " targeted for " +
                parentId))
    {
        return null;
    }

    var command = this.commandManager.commands[commandName];
    var menuitem = document.createElement ("menuitem");
    menuitem.setAttribute ("id", parentId + ":" + commandName);
    menuitem.setAttribute ("commandname", command.name);
    // Add keys if this isn't a context menu:
    if (parentId.indexOf("context") != 0)
        menuitem.setAttribute("key", "key:" + command.name);
    menuitem.setAttribute("accesskey", command.accesskey);
    var label = command.label.replace("&", "");
    menuitem.setAttribute ("label", label);
    if (command.format)
    {
        menuitem.setAttribute("format", command.format);
        menuitem.setAttribute("backupLabel", label);
    }

    if ((typeof attribs == "object") && attribs)
    {
        for (var p in attribs)
            menuitem.setAttribute (p, attribs[p]);
        if ("repeatfor" in attribs)
            menuitem.setAttribute("repeatid", this.repeatId++);
    }

    command.uiElements.push(menuitem);
    parentNode.insertBefore (menuitem, beforeNode);
    /* It seems, bob only knows why, that this must be done AFTER the node is
     * added to the document.
     */
    menuitem.addEventListener("command", this.onMenuCommand, false);

    return menuitem;
}

/**
 * Appends a menuseparator to an existing menu or popup.
 * @param parentNode  DOM Node to insert into
 * @param beforeNode  DOM Node already contained by parentNode, to insert before
 * @param attribs Object containing CSS attributes to set on the element.
 */
MenuManager.prototype.appendMenuSeparator =
function mmgr_addsep (parentNode, beforeNode, attribs)
{
    var document = parentNode.ownerDocument;
    var menuitem = document.createElement ("menuseparator");
    menuitem.setAttribute ("isSeparator", true);
    if (typeof attribs == "object")
    {
        for (var p in attribs)
            menuitem.setAttribute (p, attribs[p]);
    }
    parentNode.insertBefore (menuitem, beforeNode);

    return menuitem;
}

/**
 * Appends a toolbaritem to an existing box element.
 * @param parentNode  DOM Node to insert into
 * @param beforeNode  DOM Node already contained by parentNode, to insert before
 * @param command A reference to the CommandRecord this toolbaritem will
 *                represent.
 * @param attribs Object containing CSS attributes to set on the element.
 */
MenuManager.prototype.appendToolbarItem =
function mmgr_addtb (parentNode, beforeNode, commandName, attribs)
{
    if (commandName == "-")
        return this.appendToolbarSeparator(parentNode, beforeNode, attribs);

    var parentId = parentNode.getAttribute("id");

    if (!ASSERT(commandName in this.commandManager.commands,
                "unknown command " + commandName + " targeted for " +
                parentId))
    {
        return null;
    }

    var command = this.commandManager.commands[commandName];
    var document = parentNode.ownerDocument;
    var tbitem = document.createElement ("toolbarbutton");

    var id = parentNode.getAttribute("id") + ":" + commandName;
    tbitem.setAttribute ("id", id);
    tbitem.setAttribute ("class", "toolbarbutton-1");
    if (command.tip)
        tbitem.setAttribute ("tooltiptext", command.tip);
    tbitem.setAttribute ("label", command.label.replace("&", ""));
    tbitem.setAttribute ("oncommand",
                         "dispatch('" + commandName + "');");
    if (typeof attribs == "object")
    {
        for (var p in attribs)
            tbitem.setAttribute (p, attribs[p]);
    }

    command.uiElements.push(tbitem);
    parentNode.insertBefore (tbitem, beforeNode);

    return tbitem;
}

/**
 * Appends a toolbarseparator to an existing box.
 * @param parentNode  DOM Node to insert into
 * @param beforeNode  DOM Node already contained by parentNode, to insert before
 * @param attribs Object containing CSS attributes to set on the element.
 */
MenuManager.prototype.appendToolbarSeparator =
function mmgr_addmenu (parentNode, beforeNode, attribs)
{
    var document = parentNode.ownerDocument;
    var tbitem = document.createElement ("toolbarseparator");
    tbitem.setAttribute ("isSeparator", true);
    if (typeof attribs == "object")
    {
        for (var p in attribs)
            tbitem.setAttribute (p, attribs[p]);
    }
    parentNode.appendChild (tbitem);

    return tbitem;
}

/**
 * Creates menu DOM nodes from a menu specification.
 * @param parentNode  DOM Node to insert into
 * @param beforeNode  DOM Node already contained by parentNode, to insert before
 * @param menuSpec    array of menu items
 */
MenuManager.prototype.createMenu =
function mmgr_newmenu (parentNode, beforeNode, menuName, domId, attribs)
{
    if (typeof domId == "undefined")
        domId = menuName;

    if (!ASSERT(menuName in this.menuSpecs, "unknown menu name " + menuName))
        return null;

    var menuSpec = this.menuSpecs[menuName];
    if (!("accesskey" in menuSpec))
        menuSpec.accesskey = getAccessKey(menuSpec.label);

    var subMenu = this.appendSubMenu(parentNode, beforeNode, menuName, domId,
                                     menuSpec.label, menuSpec.accesskey,
                                     attribs);

    // Keep track where we're adding popup nodes derived from some menuSpec
    if (!("uiElements" in this.menuSpecs[menuName]))
        this.menuSpecs[menuName].uiElements = [subMenu];
    else if (!arrayContains(this.menuSpecs[menuName].uiElements, subMenu))
        this.menuSpecs[menuName].uiElements.push(subMenu);

    this.createMenuItems (subMenu, null, menuSpec.items);
    return subMenu;
}

MenuManager.prototype.createMenuItems =
function mmgr_newitems (parentNode, beforeNode, menuItems)
{
    function itemAttribs()
    {
        return (1 in menuItems[i]) ? menuItems[i][1] : null;
    };

    var parentId = parentNode.getAttribute("id");

    for (var i in menuItems)
    {
        var itemName = menuItems[i][0];
        if (itemName[0] == ">")
        {
            itemName = itemName.substr(1);
            if (!ASSERT(itemName in this.menuSpecs,
                        "unknown submenu " + itemName + " referenced in " +
                        parentId))
            {
                continue;
            }
            this.createMenu (parentNode, beforeNode, itemName,
                             parentId + ":" + itemName, itemAttribs());
        }
        else if (itemName in this.commandManager.commands)
        {
            this.appendMenuItem (parentNode, beforeNode, itemName,
                                 itemAttribs());
        }
        else if (itemName == "-")
        {
            this.appendMenuSeparator (parentNode, beforeNode, itemAttribs());
        }
        else
        {
            dd ("unknown command " + itemName + " referenced in " + parentId);
        }
    }
}