gecko-dev/browser/devtools/styleeditor/utils.js

40 строки
1.2 KiB
JavaScript

/* -*- Mode: Javascript; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
/* 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/. */
const {Cc, Ci, Cu, Cr} = require("chrome");
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource:///modules/devtools/shared/event-emitter.js");
exports.PREF_ORIG_SOURCES = "devtools.styleeditor.source-maps-enabled";
/**
* A PreferenceObserver observes a pref branch for pref changes.
* It emits an event for each preference change.
*/
function PrefObserver(branchName) {
this.branchName = branchName;
this.branch = Services.prefs.getBranch(branchName);
this.branch.addObserver("", this, false);
EventEmitter.decorate(this);
}
exports.PrefObserver = PrefObserver;
PrefObserver.prototype = {
observe: function(subject, topic, data) {
if (topic == "nsPref:changed") {
this.emit(this.branchName + data);
}
},
destroy: function() {
if (this.branch) {
this.branch.removeObserver('', this);
}
}
};