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: "use strict";
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "unstable"
michael@0: };
michael@0: 
michael@0: const { EventEmitter } = require('../deprecated/events');
michael@0: const unload = require('../system/unload');
michael@0: 
michael@0: const Registry = EventEmitter.compose({
michael@0:   _registry: null,
michael@0:   _constructor: null,
michael@0:   constructor: function Registry(constructor) {
michael@0:     this._registry = [];
michael@0:     this._constructor = constructor;
michael@0:     this.on('error', this._onError = this._onError.bind(this));
michael@0:     unload.ensure(this, "_destructor");
michael@0:   },
michael@0:   _destructor: function _destructor() {
michael@0:     let _registry = this._registry.slice(0);
michael@0:     for each (let instance in _registry)
michael@0:       this._emit('remove', instance);
michael@0:     this._registry.splice(0);
michael@0:   },
michael@0:   _onError: function _onError(e) {
michael@0:     if (!this._listeners('error').length)
michael@0:       console.error(e);
michael@0:   },
michael@0:   has: function has(instance) {
michael@0:     let _registry = this._registry;
michael@0:     return (
michael@0:       (0 <= _registry.indexOf(instance)) ||
michael@0:       (instance && instance._public && 0 <= _registry.indexOf(instance._public))
michael@0:     );
michael@0:   },
michael@0:   add: function add(instance) {
michael@0:     let { _constructor, _registry } = this; 
michael@0:     if (!(instance instanceof _constructor))
michael@0:       instance = new _constructor(instance);
michael@0:     if (0 > _registry.indexOf(instance)) {
michael@0:       _registry.push(instance);
michael@0:       this._emit('add', instance);
michael@0:     }
michael@0:     return instance;
michael@0:   },
michael@0:   remove: function remove(instance) {
michael@0:     let _registry = this._registry;
michael@0:     let index = _registry.indexOf(instance)
michael@0:     if (0 <= index) {
michael@0:       this._emit('remove', instance);
michael@0:       _registry.splice(index, 1);
michael@0:     }
michael@0:   }
michael@0: });
michael@0: exports.Registry = Registry;
michael@0: