gecko/addon-sdk/source/lib/sdk/hotkeys.js

41 lines
1.4 KiB
JavaScript

/* 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/. */
"use strict";
module.metadata = {
"stability": "stable"
};
const INVALID_HOTKEY = "Hotkey must have at least one modifier.";
const { toJSON: jsonify, toString: stringify,
isFunctionKey } = require("./keyboard/utils");
const { register, unregister } = require("./keyboard/hotkeys");
const Hotkey = exports.Hotkey = function Hotkey(options) {
if (!(this instanceof Hotkey))
return new Hotkey(options);
// Parsing key combination string.
let hotkey = jsonify(options.combo);
if (!isFunctionKey(hotkey.key) && !hotkey.modifiers.length) {
throw new TypeError(INVALID_HOTKEY);
}
this.onPress = options.onPress && options.onPress.bind(this);
this.toString = stringify.bind(null, hotkey);
// Registering listener on keyboard combination enclosed by this hotkey.
// Please note that `this.toString()` is a normalized version of
// `options.combination` where order of modifiers is sorted and `accel` is
// replaced with platform specific key.
register(this.toString(), this.onPress);
// We freeze instance before returning it in order to make it's properties
// read-only.
return Object.freeze(this);
};
Hotkey.prototype.destroy = function destroy() {
unregister(this.toString(), this.onPress);
};