1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/toolkit/components/url-classifier/content/moz/observer.js Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,144 @@
1.4 +# This Source Code Form is subject to the terms of the Mozilla Public
1.5 +# License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 +# file, You can obtain one at http://mozilla.org/MPL/2.0/.
1.7 +
1.8 +
1.9 +// A couple of classes to simplify creating observers.
1.10 +//
1.11 +// // Example1:
1.12 +//
1.13 +// function doSomething() { ... }
1.14 +// var observer = new G_ObserverWrapper(topic, doSomething);
1.15 +// someObj.addObserver(topic, observer);
1.16 +//
1.17 +// // Example2:
1.18 +//
1.19 +// function doSomething() { ... }
1.20 +// new G_ObserverServiceObserver("profile-after-change",
1.21 +// doSomething,
1.22 +// true /* run only once */);
1.23 +
1.24 +
1.25 +/**
1.26 + * This class abstracts the admittedly simple boilerplate required of
1.27 + * an nsIObserver. It saves you the trouble of implementing the
1.28 + * indirection of your own observe() function.
1.29 + *
1.30 + * @param topic String containing the topic the observer will filter for
1.31 + *
1.32 + * @param observeFunction Reference to the function to call when the
1.33 + * observer fires
1.34 + *
1.35 + * @constructor
1.36 + */
1.37 +function G_ObserverWrapper(topic, observeFunction) {
1.38 + this.debugZone = "observer";
1.39 + this.topic_ = topic;
1.40 + this.observeFunction_ = observeFunction;
1.41 +}
1.42 +
1.43 +/**
1.44 + * XPCOM
1.45 + */
1.46 +G_ObserverWrapper.prototype.QueryInterface = function(iid) {
1.47 + if (iid.equals(Ci.nsISupports) || iid.equals(Ci.nsIObserver))
1.48 + return this;
1.49 + throw Components.results.NS_ERROR_NO_INTERFACE;
1.50 +}
1.51 +
1.52 +/**
1.53 + * Invoked by the thingy being observed
1.54 + */
1.55 +G_ObserverWrapper.prototype.observe = function(subject, topic, data) {
1.56 + if (topic == this.topic_)
1.57 + this.observeFunction_(subject, topic, data);
1.58 +}
1.59 +
1.60 +
1.61 +/**
1.62 + * This class abstracts the admittedly simple boilerplate required of
1.63 + * observing an observerservice topic. It implements the indirection
1.64 + * required, and automatically registers to hear the topic.
1.65 + *
1.66 + * @param topic String containing the topic the observer will filter for
1.67 + *
1.68 + * @param observeFunction Reference to the function to call when the
1.69 + * observer fires
1.70 + *
1.71 + * @param opt_onlyOnce Boolean indicating if the observer should unregister
1.72 + * after it has fired
1.73 + *
1.74 + * @constructor
1.75 + */
1.76 +function G_ObserverServiceObserver(topic, observeFunction, opt_onlyOnce) {
1.77 + this.debugZone = "observerserviceobserver";
1.78 + this.topic_ = topic;
1.79 + this.observeFunction_ = observeFunction;
1.80 + this.onlyOnce_ = !!opt_onlyOnce;
1.81 +
1.82 + this.observer_ = new G_ObserverWrapper(this.topic_,
1.83 + BindToObject(this.observe_, this));
1.84 + this.observerService_ = Cc["@mozilla.org/observer-service;1"]
1.85 + .getService(Ci.nsIObserverService);
1.86 + this.observerService_.addObserver(this.observer_, this.topic_, false);
1.87 +}
1.88 +
1.89 +/**
1.90 + * Unregister the observer from the observerservice
1.91 + */
1.92 +G_ObserverServiceObserver.prototype.unregister = function() {
1.93 + this.observerService_.removeObserver(this.observer_, this.topic_);
1.94 + this.observerService_ = null;
1.95 +}
1.96 +
1.97 +/**
1.98 + * Invoked by the observerservice
1.99 + */
1.100 +G_ObserverServiceObserver.prototype.observe_ = function(subject, topic, data) {
1.101 + this.observeFunction_(subject, topic, data);
1.102 + if (this.onlyOnce_)
1.103 + this.unregister();
1.104 +}
1.105 +
1.106 +#ifdef DEBUG
1.107 +function TEST_G_Observer() {
1.108 + if (G_GDEBUG) {
1.109 +
1.110 + var z = "observer UNITTEST";
1.111 + G_debugService.enableZone(z);
1.112 +
1.113 + G_Debug(z, "Starting");
1.114 +
1.115 + var regularObserverRan = 0;
1.116 + var observerServiceObserverRan = 0;
1.117 +
1.118 + function regularObserver() {
1.119 + regularObserverRan++;
1.120 + };
1.121 +
1.122 + function observerServiceObserver() {
1.123 + observerServiceObserverRan++;
1.124 + };
1.125 +
1.126 + var service = Cc["@mozilla.org/observer-service;1"]
1.127 + .getService(Ci.nsIObserverService);
1.128 + var topic = "google-observer-test";
1.129 +
1.130 + var o1 = new G_ObserverWrapper(topic, regularObserver);
1.131 + service.addObserver(o1, topic, false);
1.132 +
1.133 + new G_ObserverServiceObserver(topic,
1.134 + observerServiceObserver, true /* once */);
1.135 +
1.136 + // Notifications happen synchronously, so this is easy
1.137 + service.notifyObservers(null, topic, null);
1.138 + service.notifyObservers(null, topic, null);
1.139 +
1.140 + G_Assert(z, regularObserverRan == 2, "Regular observer broken");
1.141 + G_Assert(z, observerServiceObserverRan == 1, "ObsServObs broken");
1.142 +
1.143 + service.removeObserver(o1, topic);
1.144 + G_Debug(z, "PASSED");
1.145 + }
1.146 +}
1.147 +#endif
