import { JSONObject } from '../algorithm/json';
import { IDisposable } from '../core/disposable';
import { ISignal } from '../core/signaling';
/**
 * A registry which holds user-defined commands.
 */
export declare class CommandRegistry {
    /**
     * Construct a new command registry.
     */
    constructor();
    /**
     * A signal emmitted when a command is changed.
     */
    commandChanged: ISignal<CommandRegistry, CommandRegistry.ICommandChangedArgs>;
    /**
     * A signal emitted when a command is executed.
     */
    commandExecuted: ISignal<CommandRegistry, CommandRegistry.ICommandExecutedArgs>;
    /**
     * List the ids of the registered commands.
     *
     * @returns A new array of the registered command ids.
     */
    listCommands(): string[];
    /**
     * Test whether a specific command is registered.
     *
     * @param id - The id of the command of interest.
     *
     * @returns `true` if the command is registered, `false` otherwise.
     */
    hasCommand(id: string): boolean;
    /**
     * Add a command to the registry.
     *
     * @param id - The unique id of the command.
     *
     * @param options - The options for the command.
     *
     * @returns A disposable which will unregister the command.
     *
     * @throws An error if the given `id` is already registered.
     */
    addCommand(id: string, options: CommandRegistry.ICommandOptions): IDisposable;
    /**
     * Notify listeners that the state of a command has changed.
     *
     * @param id - The id of the command which has changed.
     *
     * #### Notes
     * This method should be called by the command author whenever the
     * application state changes such that the results of the command
     * metadata functions may have changed.
     *
     * This will cause the `commandChanged` signal to be emitted.
     *
     * If the command is not registered, this is a no-op.
     */
    notifyCommandChanged(id: string): void;
    /**
     * Get the display label for a specific command.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns The display label for the command.
     *
     * #### Notes
     * Returns an empty string if the command is not registered.
     */
    label(id: string, args: JSONObject): string;
    /**
     * Get the mnemonic index for a specific command.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns The mnemonic index for the command.
     *
     * #### Notes
     * Returns `-1` if the command is not registered.
     */
    mnemonic(id: string, args: JSONObject): number;
    /**
     * Get the icon class for a specific command.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns The icon class for the command.
     *
     * #### Notes
     * Returns an empty string if the command is not registered.
     */
    icon(id: string, args: JSONObject): string;
    /**
     * Get the short form caption for a specific command.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns The caption for the command.
     *
     * #### Notes
     * Returns an empty string if the command is not registered.
     */
    caption(id: string, args: JSONObject): string;
    /**
     * Get the usage help text for a specific command.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns The usage text for the command.
     *
     * #### Notes
     * Returns an empty string if the command is not registered.
     */
    usage(id: string, args: JSONObject): string;
    /**
     * Get the extra class name for a specific command.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns The class name for the command.
     *
     * #### Notes
     * Returns an empty string if the command is not registered.
     */
    className(id: string, args: JSONObject): string;
    /**
     * Test whether a specific command is enabled.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns `true` if the command is enabled, `false` otherwise.
     *
     * #### Notes
     * Returns `false` if the command is not registered.
     */
    isEnabled(id: string, args: JSONObject): boolean;
    /**
     * Test whether a specific command is toggled.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns `true` if the command is toggled, `false` otherwise.
     *
     * #### Notes
     * Returns `false` if the command is not registered.
     */
    isToggled(id: string, args: JSONObject): boolean;
    /**
     * Test whether a specific command is visible.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns `true` if the command is visible, `false` otherwise.
     *
     * #### Notes
     * Returns `false` if the command is not registered.
     */
    isVisible(id: string, args: JSONObject): boolean;
    /**
     * Execute a specific command.
     *
     * @param id - The id of the command of interest.
     *
     * @param args - The arguments for the command.
     *
     * @returns A promise which resolves to the result of the command.
     *
     * #### Notes
     * The promise will reject if the command is not registered.
     */
    execute(id: string, args: JSONObject): Promise<any>;
    private _commands;
}
/**
 * The namespace for the `CommandRegistry` class statics.
 */
export declare namespace CommandRegistry {
    /**
     * An arguments object for the `commandChanged` signal.
     */
    interface ICommandChangedArgs {
        /**
         * The id of the associated command.
         */
        id: string;
        /**
         * Whether the command was added, removed, or changed.
         */
        type: 'added' | 'removed' | 'changed';
    }
    /**
     * An arguments object for the `commandExecuted` signal.
     */
    interface ICommandExecutedArgs {
        /**
         * The id of the associated command.
         */
        id: string;
        /**
         * The arguments object passed to the command.
         */
        args: JSONObject;
    }
    /**
     * A type alias for a command execute function.
     *
     * @param args - The arguments for the command.
     *
     * @returns The command result, a promise to the result, or void.
     */
    type ExecFunc = (args: JSONObject) => any;
    /**
     * A type alias for a command string function.
     *
     * @param args - The arguments for the command.
     *
     * @returns The relevant string result.
     */
    type StringFunc = (args: JSONObject) => string;
    /**
     * A type alias for a command number function.
     *
     * @param args - The arguments for the command.
     *
     * @returns The relevant number result.
     */
    type NumberFunc = (args: JSONObject) => number;
    /**
     * A type alias for a command boolean function.
     *
     * @param args - The arguments for the command.
     *
     * @returns The relevant boolean result.
     */
    type BoolFunc = (args: JSONObject) => boolean;
    /**
     * An options object for creating a command.
     *
     * #### Notes
     * A command is an abstract representation of code to be executed along
     * with metadata for describing how the command should be displayed in
     * a visual representation.
     *
     * A command is a collection of functions, *not* methods. The command
     * registry will always invoke the command functions with a `thisArg`
     * which is `undefined`.
     *
     * The metadata functions for the command should be well behaved in
     * the presence of `null` args by returning a default value.
     */
    interface ICommandOptions {
        /**
         * The function to invoke when the command is executed.
         *
         * #### Notes
         * This function may be invoked manually by the user, even when
         * the `isEnabled` function returns `false`.
         */
        execute: ExecFunc;
        /**
         * The label text for the command.
         *
         * #### Notes
         * This can be a string literal, or a function which returns the
         * label based on the provided command arguments.
         *
         * The default value is an empty string.
         */
        label?: string | StringFunc;
        /**
         * The index of the mnemonic character for the command.
         *
         * #### Notes
         * This can be an index literal, or a function which returns the
         * mnemonic index based on the provided command arguments.
         *
         * The default value is `-1`.
         */
        mnemonic?: number | NumberFunc;
        /**
         * The icon class for the command.
         *
         * #### Notes
         * This class name will be added to the icon node for the visual
         * representation of the command.
         *
         * Multiple class names can be separated with white space.
         *
         * This can be a string literal, or a function which returns the
         * icon based on the provided command arguments.
         *
         * The default value is an empty string.
         */
        icon?: string | StringFunc;
        /**
         * The caption for the command.
         *
         * #### Notes
         * This should be a simple one line description of the command. It
         * is used by some visual representations to show quick info about
         * the command.
         *
         * This can be a string literal, or a function which returns the
         * caption based on the provided command arguments.
         *
         * The default value is an empty string.
         */
        caption?: string | StringFunc;
        /**
         * The usage text for the command.
         *
         * #### Notes
         * This should be a full description of the command, which includes
         * information about the structure of the arguments and the type of
         * the return value. It is used by some visual representations when
         * displaying complete help info about the command.
         *
         * This can be a string literal, or a function which returns the
         * usage text based on the provided command arguments.
         *
         * The default value is an empty string.
         */
        usage?: string | StringFunc;
        /**
         * The general class name for the command.
         *
         * #### Notes
         * This class name will be added to the primary node for the visual
         * representation of the command.
         *
         * Multiple class names can be separated with white space.
         *
         * This can be a string literal, or a function which returns the
         * class name based on the provided command arguments.
         *
         * The default value is an empty string.
         */
        className?: string | StringFunc;
        /**
         * A function which indicates whether the command is enabled.
         *
         * #### Notes
         * Visual representations may use this value to display a disabled
         * command as grayed-out or in some other non-interactive fashion.
         *
         * The default value is `true`.
         */
        isEnabled?: BoolFunc;
        /**
         * A function which indicates whether the command is toggled.
         *
         * #### Notes
         * Visual representations may use this value to display a toggled
         * command in a different form, such as a check mark icon for a
         * menu item or a depressed state for a toggle button.
         *
         * The default value is `false`.
         */
        isToggled?: BoolFunc;
        /**
         * A function which indicates whether the command is visible.
         *
         * #### Notes
         * Visual representations may use this value to hide or otherwise
         * not display a non-visible command.
         *
         * The default value is `true`.
         */
        isVisible?: BoolFunc;
    }
}