The Tor Browser / file revision

 /* 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 { Ci } = require("chrome");

 const method = require("../../method/core");

 const { add, remove, iterator } = require("../lang/weak-set");

 let getTargetWindow = method("getTargetWindow");

 getTargetWindow.define(function (target) {

   if (target instanceof Ci.nsIDOMWindow)

     return target;

   if (target instanceof Ci.nsIDOMDocument)

     return target.defaultView || null;

   return null;

 });

 exports.getTargetWindow = getTargetWindow;

 let attachTo = method("attachTo");

 exports.attachTo = attachTo;

 let detachFrom = method("detatchFrom");

 exports.detachFrom = detachFrom;

 function attach(modification, target) {

   if (!modification)

     return;

   let window = getTargetWindow(target);

   attachTo(modification, window);

   // modification are stored per content; `window` reference can still be the

   // same even if the content is changed, therefore `document` is used instead.

   add(modification, window.document);

 }

 exports.attach = attach;

 function detach(modification, target) {

   if (!modification)

     return;

   if (target) {

     let window = getTargetWindow(target);

     detachFrom(modification, window);

     remove(modification, window.document);

   }

   else {

     let documents = iterator(modification);

     for (let document of documents) {

       detachFrom(modification, document.defaultView);

       remove(modification, document);

     }

   }

 }

 exports.detach = detach;