| Interface | Description | 
|---|---|
| Image | An Image is a graphical element that can be displayed on a  Device. | 
| MouseListener | A widget has to implement this interface to be able to receive user mouse events. | 
| Class | Description | 
|---|---|
| Composite | A composite is a widget that can contain other  Widgetinstances, following the composite pattern. | 
| Device | A device represents the physical look of a device. | 
| EventQueue | The events queue is a mechanism to store some events in a linked list. | 
| FrontPanel | This is the super class of the front panel engines. | 
| Widget | Widget is the superclass of all the user interface objects. | 
| Enum | Description | 
|---|---|
| MouseListener.MouseButton | Some mouse events hold a mouse button. | 
| Annotation Type | Description | 
|---|---|
| Widget.WidgetAttribute | This interface describes only one attribute of the widget description. | 
| Widget.WidgetDescription | This interface allows a subclass of  Widgetto describe itself. |