gecko/toolkit/components/url-classifier/content/moz/observer.js

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# ***** BEGIN LICENSE BLOCK *****
# Version: MPL 1.1/GPL 2.0/LGPL 2.1
#
# The contents of this file are subject to the Mozilla Public License Version
# 1.1 (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
# http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
# for the specific language governing rights and limitations under the
# License.
#
# The Original Code is Google Safe Browsing.
#
# The Initial Developer of the Original Code is Google Inc.
# Portions created by the Initial Developer are Copyright (C) 2006
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
# Fritz Schneider <fritz@google.com> (original author)
#
# Alternatively, the contents of this file may be used under the terms of
# either the GNU General Public License Version 2 or later (the "GPL"), or
# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
# in which case the provisions of the GPL or the LGPL are applicable instead
# of those above. If you wish to allow use of your version of this file only
# under the terms of either the GPL or the LGPL, and not to allow others to
# use your version of this file under the terms of the MPL, indicate your
# decision by deleting the provisions above and replace them with the notice
# and other provisions required by the GPL or the LGPL. If you do not delete
# the provisions above, a recipient may use your version of this file under
# the terms of any one of the MPL, the GPL or the LGPL.
#
# ***** END LICENSE BLOCK *****
// A couple of classes to simplify creating observers.
//
// // Example1:
//
// function doSomething() { ... }
// var observer = new G_ObserverWrapper(topic, doSomething);
// someObj.addObserver(topic, observer);
//
// // Example2:
//
// function doSomething() { ... }
// new G_ObserverServiceObserver("profile-after-change",
// doSomething,
// true /* run only once */);
/**
* This class abstracts the admittedly simple boilerplate required of
* an nsIObserver. It saves you the trouble of implementing the
* indirection of your own observe() function.
*
* @param topic String containing the topic the observer will filter for
*
* @param observeFunction Reference to the function to call when the
* observer fires
*
* @constructor
*/
function G_ObserverWrapper(topic, observeFunction) {
this.debugZone = "observer";
this.topic_ = topic;
this.observeFunction_ = observeFunction;
}
/**
* XPCOM
*/
G_ObserverWrapper.prototype.QueryInterface = function(iid) {
if (iid.equals(Ci.nsISupports) || iid.equals(Ci.nsIObserver))
return this;
throw Components.results.NS_ERROR_NO_INTERFACE;
}
/**
* Invoked by the thingy being observed
*/
G_ObserverWrapper.prototype.observe = function(subject, topic, data) {
if (topic == this.topic_)
this.observeFunction_(subject, topic, data);
}
/**
* This class abstracts the admittedly simple boilerplate required of
* observing an observerservice topic. It implements the indirection
* required, and automatically registers to hear the topic.
*
* @param topic String containing the topic the observer will filter for
*
* @param observeFunction Reference to the function to call when the
* observer fires
*
* @param opt_onlyOnce Boolean indicating if the observer should unregister
* after it has fired
*
* @constructor
*/
function G_ObserverServiceObserver(topic, observeFunction, opt_onlyOnce) {
this.debugZone = "observerserviceobserver";
this.topic_ = topic;
this.observeFunction_ = observeFunction;
this.onlyOnce_ = !!opt_onlyOnce;
this.observer_ = new G_ObserverWrapper(this.topic_,
BindToObject(this.observe_, this));
this.observerService_ = Cc["@mozilla.org/observer-service;1"]
.getService(Ci.nsIObserverService);
this.observerService_.addObserver(this.observer_, this.topic_, false);
}
/**
* Unregister the observer from the observerservice
*/
G_ObserverServiceObserver.prototype.unregister = function() {
this.observerService_.removeObserver(this.observer_, this.topic_);
this.observerService_ = null;
}
/**
* Invoked by the observerservice
*/
G_ObserverServiceObserver.prototype.observe_ = function(subject, topic, data) {
this.observeFunction_(subject, topic, data);
if (this.onlyOnce_)
this.unregister();
}
#ifdef DEBUG
function TEST_G_Observer() {
if (G_GDEBUG) {
var z = "observer UNITTEST";
G_debugService.enableZone(z);
G_Debug(z, "Starting");
var regularObserverRan = 0;
var observerServiceObserverRan = 0;
function regularObserver() {
regularObserverRan++;
};
function observerServiceObserver() {
observerServiceObserverRan++;
};
var service = Cc["@mozilla.org/observer-service;1"]
.getService(Ci.nsIObserverService);
var topic = "google-observer-test";
var o1 = new G_ObserverWrapper(topic, regularObserver);
service.addObserver(o1, topic, false);
new G_ObserverServiceObserver(topic,
observerServiceObserver, true /* once */);
// Notifications happen synchronously, so this is easy
service.notifyObservers(null, topic, null);
service.notifyObservers(null, topic, null);
G_Assert(z, regularObserverRan == 2, "Regular observer broken");
G_Assert(z, observerServiceObserverRan == 1, "ObsServObs broken");
service.removeObserver(o1, topic);
G_Debug(z, "PASSED");
}
}
#endif