/**
 * Service for binding keyboard shortcuts to execute commands
 *
 * A keybinding is a sequence or key combination on a computer keyboard which
 * invokes commands. This service supports key bindings as a way of responding
 * to individual keys typed by a user. The key combination can be pressing a single
 * key or a sequence of keys one after the other.
 *
 * The service works together with the `CommandBus` to execute the commands and
 * a command needs to already be registered on the command bus in order to be
 * bound as a keyboard shortcut.
 *
 * The following example registers the command `MyCommand` to be handled by
 * `MyHandler` and creates a keybinding for it. The `bind` method takes the key
 * combination and command object as input.
 *
 * Later, if the keybinding no longer is needed it can be removed with the
 * `unbind` method.
 *
 * @example
 * // The command bus needs to have a handler registered for the command
 * // before it can be bound to a key sequence
 * const handler = new MyHandler();
 * commandBus.register(MyCommand, handler);
 *
 * // Bind 'ctrl+s' to trigger the command
 * const command = new MyCommand();
 * keybindingRegistry.bind('ctrl+s', command);
 *
 * // Remove the binding when we no longer need it to trigger the command
 * keybindingRegistry.unbind('ctrl+s')
 * @note This service is work in progress
 * @private
 */
export interface KeybindingRegistry {
    /**
     * Bind a command to a specific key combination to add it to the registry
     *
     * @param {string} keys the string representation of keys
     * @param {Object} command the command to trigger when keys are pressed
     * @throws Will throw an error if the command is invalid or not registered
     */
    bind: (keys: string, command: object) => void;
    /**
     * Unbind a keybinding to remove it from the registry
     *
     * @param {string} keys the string representation of the key combination
     * @param {Object} command the command connected to the key combination
     */
    unbind: (keys: string, command: object) => void;
    /**
     * Get a list of the key bindings that are currently in the registry
     *
     * @returns {Keybinding[]} the list of command and its specific key combination
     */
    getKeybindings: () => Keybinding[];
    /**
     * Checks if a key combination or a specific keybinding is already bound
     *
     * @param {string} keys the string representation of a key combination
     * @param {Object} command the command connected to the key combination
     * @returns {boolean} true if key combination already exists, else false
     */
    isBound: (keys: string, command?: object) => boolean;
}
/**
 * A key combination and its corresponding command that will be triggered when
 * the key combination is pressed
 */
export interface Keybinding {
    /**
     * The string representation of key combination
     */
    keys: string;
    /**
     * The command to trigger when the key combination is pressed
     */
    command: object;
}