The DockItem class has two methods, UpdateNow and ResetIcon, and one property, Graphics. Use the methods of the Graphics class to modify the appearance of the icon. (The Graphics property may be Nil; it is non- Nil only when an OS X window has been minimized to the dock.) The ResetIcon method resets the icon to its original state (default appearance). Since a Mac OS X icon is intended to be scaled automatically, you should design it as a 128x128 pixel icon. Call the UpdateNow method to redraw the icon. You can also use the ClearRect property of the Graphics class to start over form a blank icon. Anything you can do with a Graphics object you are able to do with the Dock's Graphics object (like drawing in a picture, or using a Shape 2D). The Dockitem property of the Application class enables you to control the DockItem for the whole application.