gecko-dev/browser/modules/ContentObservers.js

31 lines
1.1 KiB
JavaScript

/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* 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/. */
/**
* This process script is for small observers that we want to register
* once per content process, usually in order to forward content-based
* observer service notifications to the chrome process through
* message passing. Using a process script avoids having them in
* content.js and thereby registering N observers for N open tabs,
* which is bad for perf.
*/
"use strict";
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
var gDecoderDoctorObserver = function(subject, topic, data) {
let win = subject.top;
let mm = getMessageManagerForWindow(win);
if (mm) {
mm.sendAsyncMessage("DecoderDoctor:Notification", data);
}
};
function getMessageManagerForWindow(aContentWindow) {
return aContentWindow.docShell.messageManager;
}
Services.obs.addObserver(gDecoderDoctorObserver, "decoder-doctor-notification");