1 files changed, 276 insertions, 0 deletions
diff --git a/toolkit/components/url-classifier/content/moz/preferences.js b/toolkit/components/url-classifier/content/moz/preferences.js
new file mode 100644
index 000000000..30105ab34
--- /dev/null
+++ b/toolkit/components/url-classifier/content/moz/preferences.js
@@ -0,0 +1,276 @@
+# 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/.
+
+
+// Class for manipulating preferences. Aside from wrapping the pref
+// service, useful functionality includes:
+//
+// - abstracting prefobserving so that you can observe preferences
+//   without implementing nsIObserver 
+// 
+// - getters that return a default value when the pref doesn't exist 
+//   (instead of throwing)
+// 
+// - get-and-set getters
+//
+// Example:
+// 
+// var p = new PROT_Preferences();
+// dump(p.getPref("some-true-pref"));     // shows true
+// dump(p.getPref("no-such-pref", true)); // shows true   
+// dump(p.getPref("no-such-pref", null)); // shows null
+//
+// function observe(prefThatChanged) {
+//   dump("Pref changed: " + prefThatChanged);
+// };
+//
+// p.addObserver("somepref", observe);
+// p.setPref("somepref", true);            // dumps
+// p.removeObserver("somepref", observe);
+//
+// TODO: should probably have the prefobserver pass in the new and old
+//       values
+
+// TODO(tc): Maybe remove this class and just call natively since we're no
+//           longer an extension.
+
+/**
+ * A class that wraps the preferences service.
+ *
+ * @param opt_startPoint        A starting point on the prefs tree to resolve 
+ *                              names passed to setPref and getPref.
+ *
+ * @param opt_useDefaultPranch  Set to true to work against the default 
+ *                              preferences tree instead of the profile one.
+ *
+ * @constructor
+ */
+this.G_Preferences =
+function G_Preferences(opt_startPoint, opt_getDefaultBranch) {
+  this.debugZone = "prefs";
+  this.observers_ = {};
+  this.getDefaultBranch_ = !!opt_getDefaultBranch;
+
+  this.startPoint_ = opt_startPoint || null;
+}
+
+G_Preferences.setterMap_ = { "string": "setCharPref",
+                             "boolean": "setBoolPref",
+                             "number": "setIntPref" };
+
+G_Preferences.getterMap_ = {};
+G_Preferences.getterMap_[Ci.nsIPrefBranch.PREF_STRING] = "getCharPref";
+G_Preferences.getterMap_[Ci.nsIPrefBranch.PREF_BOOL] = "getBoolPref";
+G_Preferences.getterMap_[Ci.nsIPrefBranch.PREF_INT] = "getIntPref";
+
+G_Preferences.prototype.__defineGetter__('prefs_', function() {
+  var prefs;
+  var prefSvc = Cc["@mozilla.org/preferences-service;1"]
+                  .getService(Ci.nsIPrefService);
+
+  if (this.getDefaultBranch_) {
+    prefs = prefSvc.getDefaultBranch(this.startPoint_);
+  } else {
+    prefs = prefSvc.getBranch(this.startPoint_);
+  }
+
+  // QI to prefs in case we want to add observers
+  prefs.QueryInterface(Ci.nsIPrefBranchInternal);
+  return prefs;
+});
+
+/**
+ * Stores a key/value in a user preference. Valid types for val are string,
+ * boolean, and number. Complex values are not yet supported (but feel free to
+ * add them!).
+ */
+G_Preferences.prototype.setPref = function(key, val) {
+  var datatype = typeof(val);
+
+  if (datatype == "number" && (val % 1 != 0)) {
+    throw new Error("Cannot store non-integer numbers in preferences.");
+  }
+
+  var meth = G_Preferences.setterMap_[datatype];
+
+  if (!meth) {
+    throw new Error("Pref datatype {" + datatype + "} not supported.");
+  }
+
+  return this.prefs_[meth](key, val);
+}
+
+/**
+ * Retrieves a user preference. Valid types for the value are the same as for
+ * setPref. If the preference is not found, opt_default will be returned 
+ * instead.
+ */
+G_Preferences.prototype.getPref = function(key, opt_default) {
+  var type = this.prefs_.getPrefType(key);
+
+  // zero means that the specified pref didn't exist
+  if (type == Ci.nsIPrefBranch.PREF_INVALID) {
+    return opt_default;
+  }
+
+  var meth = G_Preferences.getterMap_[type];
+
+  if (!meth) {
+    throw new Error("Pref datatype {" + type + "} not supported.");
+  }
+
+  // If a pref has been cleared, it will have a valid type but won't
+  // be gettable, so this will throw.
+  try {
+    return this.prefs_[meth](key);
+  } catch(e) {
+    return opt_default;
+  }
+}
+
+/**
+ * Delete a preference. 
+ *
+ * @param which Name of preference to obliterate
+ */
+G_Preferences.prototype.clearPref = function(which) {
+  try {
+    // This throws if the pref doesn't exist, which is fine because a 
+    // nonexistent pref is cleared
+    this.prefs_.clearUserPref(which);
+  } catch(e) {}
+}
+
+/**
+ * Add an observer for a given pref.
+ *
+ * @param which String containing the pref to listen to
+ * @param callback Function to be called when the pref changes. This
+ *                 function will receive a single argument, a string 
+ *                 holding the preference name that changed
+ */
+G_Preferences.prototype.addObserver = function(which, callback) {
+  // Need to store the observer we create so we can eventually unregister it
+  if (!this.observers_[which])
+    this.observers_[which] = { callbacks: [], observers: [] };
+
+  /* only add an observer if the callback hasn't been registered yet */
+  if (this.observers_[which].callbacks.indexOf(callback) == -1) {
+    var observer = new G_PreferenceObserver(callback);
+    this.observers_[which].callbacks.push(callback);
+    this.observers_[which].observers.push(observer);
+    this.prefs_.addObserver(which, observer, false /* strong reference */);
+  }
+}
+
+/**
+ * Remove an observer for a given pref.
+ *
+ * @param which String containing the pref to stop listening to
+ * @param callback Function to remove as an observer
+ */
+G_Preferences.prototype.removeObserver = function(which, callback) {
+  var ix = this.observers_[which].callbacks.indexOf(callback);
+  G_Assert(this, ix != -1, "Tried to unregister a nonexistent observer"); 
+  this.observers_[which].callbacks.splice(ix, 1);
+  var observer = this.observers_[which].observers.splice(ix, 1)[0];
+  this.prefs_.removeObserver(which, observer);
+}
+
+/**
+ * Remove all preference observers registered through this object.
+ */
+G_Preferences.prototype.removeAllObservers = function() {
+  for (var which in this.observers_) {
+    for (var observer of this.observers_[which].observers) {
+      this.prefs_.removeObserver(which, observer);
+    }
+  }
+  this.observers_ = {};
+}
+
+/**
+ * Helper class that knows how to observe preference changes and
+ * invoke a callback when they do
+ *
+ * @constructor
+ * @param callback Function to call when the preference changes
+ */
+this.G_PreferenceObserver =
+function G_PreferenceObserver(callback) {
+  this.debugZone = "prefobserver";
+  this.callback_ = callback;
+}
+
+/**
+ * Invoked by the pref system when a preference changes. Passes the
+ * message along to the callback.
+ *
+ * @param subject The nsIPrefBranch that changed
+ * @param topic String "nsPref:changed" (aka 
+ *              NS_PREFBRANCH_PREFCHANGE_OBSERVER_ID -- but where does it
+ *              live???)
+ * @param data Name of the pref that changed
+ */
+G_PreferenceObserver.prototype.observe = function(subject, topic, data) {
+  G_Debug(this, "Observed pref change: " + data);
+  this.callback_(data);
+}
+
+/**
+ * XPCOM cruft
+ *
+ * @param iid Interface id of the interface the caller wants
+ */
+G_PreferenceObserver.prototype.QueryInterface = function(iid) {
+  if (iid.equals(Ci.nsISupports) || 
+      iid.equals(Ci.nsIObserver) ||
+      iid.equals(Ci.nsISupportsWeakReference))
+    return this;
+  throw Components.results.NS_ERROR_NO_INTERFACE;
+}
+
+#ifdef DEBUG
+// UNITTESTS
+this.TEST_G_Preferences = function TEST_G_Preferences() {
+  if (G_GDEBUG) {
+    var z = "preferences UNITTEST";
+    G_debugService.enableZone(z);
+    G_Debug(z, "Starting");
+
+    var p = new G_Preferences();
+    
+    var testPref = "test-preferences-unittest";
+    var noSuchPref = "test-preferences-unittest-aypabtu";
+    
+    // Used to test observing
+    var observeCount = 0;
+    let observe = function (prefChanged) {
+      G_Assert(z, prefChanged == testPref, "observer broken");
+      observeCount++;
+    };
+
+    // Test setting, getting, and observing
+    p.addObserver(testPref, observe);
+    p.setPref(testPref, true);
+    G_Assert(z, p.getPref(testPref), "get or set broken");
+    G_Assert(z, observeCount == 1, "observer adding not working");
+
+    p.removeObserver(testPref, observe);
+
+    p.setPref(testPref, false);
+    G_Assert(z, observeCount == 1, "observer removal not working");
+    G_Assert(z, !p.getPref(testPref), "get broken");
+    
+    // Remember to clean up the prefs we've set, and test removing prefs 
+    // while we're at it
+    p.clearPref(noSuchPref);
+    G_Assert(z, !p.getPref(noSuchPref, false), "clear broken");
+    
+    p.clearPref(testPref);
+    
+    G_Debug(z, "PASSED");
+  }
+}
+#endif