Each of these widgets performs a specific user interface function. They are simple because they cannot have widget children\(emthey may only be used as leaves of the widget tree. These widgets display information or take user input. Command A push button that, when selected, may cause a specific action to take place. This widget can display a multi-line string or a bitmap or pixmap image. Grip A rectangle that, when selected, will cause an action to take place. Label A rectangle that can display a multi-line string or a bitmap or pixmap image. List A list of text strings presented in row column format that may be individually selected. When an element is selected an action may take place. Panner A rectangular area containing a slider that may be moved in two dimensions. Notification of movement may be continuous or discrete. Repeater A push button that triggers an action at an increasing rate when selected. This widget can display a multi-line string or a bitmap or pixmap image. Scrollbar A rectangular area containing a thumb that when slid along one dimension may cause a specific action to take place. The Scrollbar may be oriented horizontally or vertically. Simple The base class for most of the simple widgets. Provides a rectangular area with a settable mouse cursor and special border. StripChart A real time data graph that will automatically update and scroll. Toggle A push button that contains state information. Toggles may also be used as "radio buttons" to implement a "one of many" or "zero or one of many" group of buttons. This widget can display a multi-line string or a bitmap or pixmap image.