📝 Document the tray module.

docs/README.md

@@ -20,6 +20,7 @@ Modules for browser side:
 * [menu-item](api/menu-item.md)
 * [power-monitor](api/power-monitor.md)
 * [protocol](api/protocol.md)
+* [tray](api/tray.md)
 
 Modules for web page:
 

docs/api/tray.md

@@ -0,0 +1,59 @@
+# tray
+
+A `Tray` represents an icon in operating system's notification area, it is
+usually attached with a context menu.
+
+```javascript
+var Menu = require('menu');
+var Tray = require('tray');
+
+var appIcon = new Tray('/path/to/my/icon');
+var contextMenu = Menu.buildFromTemplate([
+  { label: 'Item1', type: 'radio' },
+  { label: 'Item2', type: 'radio' },
+  { label: 'Item3', type: 'radio', clicked: true },
+  { label: 'Item4', type: 'radio' },
+]);
+appIcon.setToolTip('This is my application.');
+appIcon.setContextMenu(contextMenu);
+```
+
+__Platform limitations:__
+
+* On OS X `clicked` event will be ignored if the tray icon has context menu.
+
+## Class: Tray
+
+`Tray` is an [EventEmitter](event-emitter).
+
+### new Tray(image)
+
+* `image` String
+
+Creates a new tray icon associated with the `image`.
+
+### Event: 'clicked'
+
+Emitted when the tray icon is clicked.
+
+### Tray.setImage(image)
+
+* `image` String
+
+Sets the `image` associated with this tray icon.
+
+### Tray.setPressedImage(image)
+
+* `image` String
+
+Sets the `image` associated with this tray icon when pressed.
+
+### Tray.setToolTip(toolTip)
+
+* `toolTip` String
+
+### Tray.setContextMenu(menu)
+
+* `menu` Menu
+
+[event-emitter]: http://nodejs.org/api/events.html#events_class_events_eventemitter