Bug 731779: Integrate the Add-on SDK loader and API libraries into Firefox (uplifting from addon-sdk a16bbd5772880b578a939eeb65102bca6560d494)

addon-sdk/source/lib/sdk/simple-prefs.js

@@ -0,0 +1,32 @@
+/* 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/. */
+'use strict';
+
+module.metadata = {
+  "stability": "experimental"
+};
+
+const { emit, off } = require("./event/core");
+const { when: unload } = require("./system/unload");
+const { PrefsTarget } = require("./preferences/event-target");
+const { id } = require("./self");
+const observers = require("./deprecated/observer-service");
+
+const ADDON_BRANCH = "extensions." + id + ".";
+const BUTTON_PRESSED = id + "-cmdPressed";
+
+const target = PrefsTarget({ branchName: ADDON_BRANCH });
+
+// Listen to clicks on buttons
+function buttonClick(subject, data) {
+  emit(target, data);
+}
+observers.add(BUTTON_PRESSED, buttonClick);
+
+// Make sure we cleanup listeners on unload.
+unload(function() {
+  observers.remove(BUTTON_PRESSED, buttonClick);
+});
+
+module.exports = target;