michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "stable"
michael@0: };
michael@0: 
michael@0: const INVALID_HOTKEY = "Hotkey must have at least one modifier.";
michael@0: 
michael@0: const { toJSON: jsonify, toString: stringify,
michael@0:         isFunctionKey } = require("./keyboard/utils");
michael@0: const { register, unregister } = require("./keyboard/hotkeys");
michael@0: 
michael@0: const Hotkey = exports.Hotkey = function Hotkey(options) {
michael@0:   if (!(this instanceof Hotkey))
michael@0:     return new Hotkey(options);
michael@0: 
michael@0:   // Parsing key combination string.
michael@0:   let hotkey = jsonify(options.combo);
michael@0:   if (!isFunctionKey(hotkey.key) && !hotkey.modifiers.length) {
michael@0:     throw new TypeError(INVALID_HOTKEY);
michael@0:   }
michael@0: 
michael@0:   this.onPress = options.onPress && options.onPress.bind(this);
michael@0:   this.toString = stringify.bind(null, hotkey);
michael@0:   // Registering listener on keyboard combination enclosed by this hotkey.
michael@0:   // Please note that `this.toString()` is a normalized version of
michael@0:   // `options.combination` where order of modifiers is sorted and `accel` is
michael@0:   // replaced with platform specific key.
michael@0:   register(this.toString(), this.onPress);
michael@0:   // We freeze instance before returning it in order to make it's properties
michael@0:   // read-only.
michael@0:   return Object.freeze(this);
michael@0: };
michael@0: Hotkey.prototype.destroy = function destroy() {
michael@0:   unregister(this.toString(), this.onPress);
michael@0: };