The Tor Browser: addon-sdk/source/lib/sdk/core/disposable.js@6474c204b198 (annotated)

addon-sdk/source/lib/sdk/core/disposable.js@6474c204b198 (annotated)

addon-sdk/source/lib/sdk/core/disposable.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* 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": "experimental"
 };
 const { Class } = require("./heritage");
 const { Observer, subscribe, unsubscribe, observe } = require("./observer");
 const { isWeak, WeakReference } = require("./reference");
 const method = require("../../method/core");
 const unloadSubject = require('@loader/unload');
 const addonUnloadTopic = "sdk:loader:destroy";
 const uninstall = method("disposable/uninstall");
 exports.uninstall = uninstall;
 const shutdown = method("disposable/shutdown");
 exports.shutdown = shutdown;
 const disable = method("disposable/disable");
 exports.disable = disable;
 const upgrade = method("disposable/upgrade");
 exports.upgrade = upgrade;
 const downgrade = method("disposable/downgrade");
 exports.downgrade = downgrade;
 const unload = method("disposable/unload");
 exports.unload = unload;
 const dispose = method("disposable/dispose");
 exports.dispose = dispose;
 dispose.define(Object, object => object.dispose());
 const setup = method("disposable/setup");
 exports.setup = setup;
 setup.define(Object, (object, ...args) => object.setup(...args));
 // Set's up disposable instance.
 const setupDisposable = disposable => {
   subscribe(disposable, addonUnloadTopic, isWeak(disposable));
 };
 // Tears down disposable instance.
 const disposeDisposable = disposable => {
   unsubscribe(disposable, addonUnloadTopic);
 };
 // Base type that takes care of disposing it's instances on add-on unload.
 // Also makes sure to remove unload listener if it's already being disposed.
 const Disposable = Class({
   implements: [Observer],
   initialize: function(...args) {
     // First setup instance before initializing it's disposal. If instance
     // fails to initialize then there is no instance to be disposed at the
     // unload.
     setup(this, ...args);
     setupDisposable(this);
   },
   destroy: function(reason) {
     // Destroying disposable removes unload handler so that attempt to dispose
     // won't be made at unload & delegates to dispose.
     disposeDisposable(this);
     unload(this, reason);
   },
   setup: function() {
     // Implement your initialize logic here.
   },
   dispose: function() {
     // Implement your cleanup logic here.
   }
 });
 exports.Disposable = Disposable;
 // Disposable instances observe add-on unload notifications in
 // order to trigger `unload` on them.
 observe.define(Disposable, (disposable, subject, topic, data) => {
   const isUnloadTopic = topic === addonUnloadTopic;
   const isUnloadSubject = subject.wrappedJSObject === unloadSubject;
   if (isUnloadTopic && isUnloadSubject) {
     unsubscribe(disposable, topic);
     unload(disposable);
   }
 });
 const unloaders = {
   destroy: dispose,
   uninstall: uninstall,
   shutdown: shutdown,
   disable: disable,
   upgrade: upgrade,
   downgrade: downgrade
 }
 const unloaded = new WeakMap();
 unload.define(Disposable, (disposable, reason) => {
   if (!unloaded.get(disposable)) {
     unloaded.set(disposable, true);
     // Pick an unload handler associated with an unload
     // reason (falling back to destroy if not found) and
     // delegate unloading to it.
     const unload = unloaders[reason] || unloaders.destroy;
     unload(disposable);
   }
 });
 // If add-on is disabled munally, it's being upgraded, downgraded
 // or uniststalled `dispose` is invoked to undo any changes that
 // has being done by it in this session.
 disable.define(Disposable, dispose);
 downgrade.define(Disposable, dispose);
 upgrade.define(Disposable, dispose);
 uninstall.define(Disposable, dispose);
 // If application is shut down no dispose is invoked as undo-ing
 // changes made by instance is likely to just waste of resources &
 // increase shutdown time. Although specefic components may choose
 // to implement shutdown handler that does something better.
 shutdown.define(Disposable, disposable => {});