import { ISequence } from '../algorithm/sequence';
import { Message } from '../core/messaging';
import { Keymap } from './keymap';
import { Menu } from './menu';
import { Title } from './title';
import { Widget } from './widget';
/**
 * A widget which displays menus as a canonical menu bar.
 */
export declare class MenuBar extends Widget {
    /**
     * Construct a new menu bar.
     *
     * @param options - The options for initializing the menu bar.
     */
    constructor(options: MenuBar.IOptions);
    /**
     * Dispose of the resources held by the widget.
     */
    dispose(): void;
    /**
     * Get the menu bar content node.
     *
     * #### Notes
     * This is the node which holds the menu title nodes.
     *
     * Modifying this node directly can lead to undefined behavior.
     *
     * This is a read-only property.
     */
    readonly contentNode: HTMLUListElement;
    /**
     * The keymap used by the menu bar.
     *
     * #### Notes
     * This is a read-only property.
     */
    readonly keymap: Keymap;
    /**
     * The renderer used by the menu bar.
     *
     * #### Notes
     * This is a read-only property.
     */
    readonly renderer: MenuBar.IRenderer;
    /**
     * A read-only sequence of the menus in the menu bar.
     *
     * #### Notes
     * This is a read-only property.
     */
    readonly menus: ISequence<Menu>;
    /**
     * Get the child menu of the menu bar.
     *
     * #### Notes
     * This will be `null` if the menu bar does not have an open menu.
     *
     * This is a read-only property.
     */
    readonly childMenu: Menu;
    /**
     * Get the currently active menu.
     *
     * #### Notes
     * This will be `null` if no menu is active.
     */
    /**
     * Set the currently active menu.
     *
     * #### Notes
     * If the menu does not exist, the menu will be set to `null`.
     */
    activeMenu: Menu;
    /**
     * Get the index of the currently active menu.
     *
     * #### Notes
     * This will be `-1` if no menu is active.
     */
    /**
     * Set the index of the currently active menu.
     *
     * #### Notes
     * If the index is out of range, the index will be set to `-1`.
     */
    activeIndex: number;
    /**
     * Open the active menu and activate its first menu item.
     *
     * #### Notes
     * If there is no active menu, this is a no-op.
     */
    openActiveMenu(): void;
    /**
     * Add a menu to the end of the menu bar.
     *
     * @param menu - The menu to add to the menu bar.
     *
     * #### Notes
     * If the menu is already added to the menu bar, it will be moved.
     */
    addMenu(menu: Menu): void;
    /**
     * Insert a menu into the menu bar at the specified index.
     *
     * @param index - The index at which to insert the menu.
     *
     * @param menu - The menu to insert into the menu bar.
     *
     * #### Notes
     * The index will be clamped to the bounds of the menus.
     *
     * If the menu is already added to the menu bar, it will be moved.
     */
    insertMenu(index: number, menu: Menu): void;
    /**
     * Remove a menu from the menu bar.
     *
     * @param menu - The menu to remove from the menu bar.
     *
     * @returns The index occupied by the menu, or `-1` if the menu
     *   was not contained in the menu bar.
     */
    removeMenu(menu: Menu): number;
    /**
     * Remove the menu at a given index from the menu bar.
     *
     * @param index - The index of the menu to remove.
     *
     * @returns The menu occupying the index, or `null` if the index
     *   is out of range.
     */
    removeMenuAt(index: number): Menu;
    /**
     * Remove all menus from the menu bar.
     */
    clearMenus(): void;
    /**
     * Handle the DOM events for the menu bar.
     *
     * @param event - The DOM event sent to the menu bar.
     *
     * #### Notes
     * This method implements the DOM `EventListener` interface and is
     * called in response to events on the menu bar's DOM nodes. It
     * should not be called directly by user code.
     */
    handleEvent(event: Event): void;
    /**
     * A message handler invoked on an `'after-attach'` message.
     */
    protected onAfterAttach(msg: Message): void;
    /**
     * A message handler invoked on a `'before-detach'` message.
     */
    protected onBeforeDetach(msg: Message): void;
    /**
     * A message handler invoked on an `'activate-request'` message.
     */
    protected onActivateRequest(msg: Message): void;
    /**
     * A message handler invoked on an `'update-request'` message.
     */
    protected onUpdateRequest(msg: Message): void;
    /**
     * Handle the `'keydown'` event for the menu bar.
     */
    private _evtKeyDown(event);
    /**
     * Handle the `'mousedown'` event for the menu bar.
     */
    private _evtMouseDown(event);
    /**
     * Handle the `'mousemove'` event for the menu bar.
     */
    private _evtMouseMove(event);
    /**
     * Handle the `'mouseleave'` event for the menu bar.
     */
    private _evtMouseLeave(event);
    /**
     * Open the child menu at the active index immediately.
     *
     * If a different child menu is already open, it will be closed,
     * even if there is no active menu.
     */
    private _openChildMenu();
    /**
     * Close the child menu immediately.
     *
     * This is a no-op if a child menu is not open.
     */
    private _closeChildMenu();
    /**
     * Handle the `aboutToClose` signal of a menu.
     */
    private _onMenuAboutToClose(sender);
    /**
     * Handle the `menuRequested` signal of a child menu.
     */
    private _onMenuMenuRequested(sender, args);
    /**
     * Handle the `changed` signal of a title object.
     */
    private _onTitleChanged(sender);
    private _keymap;
    private _activeIndex;
    private _childMenu;
    private _menus;
    private _nodes;
    private _renderer;
}
/**
 * The namespaces for the `MenuBar` class statics.
 */
export declare namespace MenuBar {
    /**
     * An options object for creating a menu bar.
     */
    interface IOptions {
        /**
         * The keymap to use for the menu bar.
         *
         * The layout installed on the keymap is used to translate a
         * `'keydown'` event into a mnemonic for navigation purposes.
         */
        keymap: Keymap;
        /**
         * A custom renderer for creating menu bar content.
         *
         * The default is a shared renderer instance.
         */
        renderer?: IRenderer;
    }
    /**
     * A renderer for use with a menu bar.
     */
    interface IRenderer {
        /**
         * Create a node for a menu bar item.
         *
         * @returns A new node for a menu bar item.
         *
         * #### Notes
         * The data in the node should be uninitialized.
         *
         * The `updateItemNode` method will be called for initialization.
         */
        createItemNode(): HTMLLIElement;
        /**
         * Update an item node to reflect the state of a menu title.
         *
         * @param node - A node created by a call to `createItemNode`.
         *
         * @param title - The menu title holding the data for the node.
         *
         * #### Notes
         * This method should completely reset the state of the node to
         * reflect the data in the menu title.
         */
        updateItemNode(node: HTMLLIElement, title: Title): void;
    }
    /**
     * The default implementation of `IRenderer`.
     */
    class Renderer implements IRenderer {
        /**
         * Create a node for a menu bar item.
         *
         * @returns A new node for a menu bar item.
         */
        createItemNode(): HTMLLIElement;
        /**
         * Update an item node to reflect the state of a menu title.
         *
         * @param node - A node created by a call to `createItemNode`.
         *
         * @param title - The menu title holding the data for the node.
         */
        updateItemNode(node: HTMLLIElement, title: Title): void;
        /**
         * Format a label into HTML for display.
         *
         * @param label - The label text of interest.
         *
         * @param mnemonic - The index of the mnemonic character.
         *
         * @return The formatted label HTML for display.
         */
        formatLabel(label: string, mnemonic: number): string;
    }
    /**
     * The default `Renderer` instance.
     */
    const defaultRenderer: Renderer;
}