1 files changed, 52 insertions, 0 deletions
diff --git a/tools/addon-sdk-1.12/lib/sdk/windows/observer.js b/tools/addon-sdk-1.12/lib/sdk/windows/observer.js
new file mode 100644
index 0000000..1097bf3
--- /dev/null
+++ b/tools/addon-sdk-1.12/lib/sdk/windows/observer.js
@@ -0,0 +1,52 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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": "unstable"
+};
+
+const { EventEmitterTrait: EventEmitter } = require("../deprecated/events");
+const { WindowTracker, windowIterator } = require("../deprecated/window-utils");
+const { DOMEventAssembler } = require("../deprecated/events/assembler");
+const { Trait } = require("../deprecated/light-traits");
+
+// Event emitter objects used to register listeners and emit events on them
+// when they occur.
+const observer = Trait.compose(DOMEventAssembler, EventEmitter).create({
+  /**
+   * Method is implemented by `EventEmitter` and is used just for emitting
+   * events on registered listeners.
+   */
+  _emit: Trait.required,
+  /**
+   * Events that are supported and emitted by the module.
+   */
+  supportedEventsTypes: [ "activate", "deactivate" ],
+  /**
+   * Function handles all the supported events on all the windows that are
+   * observed. Method is used to proxy events to the listeners registered on
+   * this event emitter.
+   * @param {Event} event
+   *    Keyboard event being emitted.
+   */
+  handleEvent: function handleEvent(event) {
+    this._emit(event.type, event.target, event);
+  }
+});
+
+// Using `WindowTracker` to track window events.
+WindowTracker({
+  onTrack: function onTrack(chromeWindow) {
+    observer._emit("open", chromeWindow);
+    observer.observe(chromeWindow);
+  },
+  onUntrack: function onUntrack(chromeWindow) {
+    observer._emit("close", chromeWindow);
+    observer.ignore(chromeWindow);
+  }
+});
+
+exports.observer = observer;