# Manager Widgets

Motif provides several classes of widgets. One such class is the Manager Class, which is a class of widgets which are used to group or control other widgets.

The Bulletin Board widget is the most basic Manager: a child is 'pinned' onto the bulletin in a specific location until moved. The Bulletin board imposes no layout policy on child widgets.

The Form widget is derived from Bulletin Board: the Form provides complex geometry management capability which allows extensive positioning, both relative and absolute, for any children.

The Row Column widget simply lays out any children in rows or columns. Motif internally uses the Row Column to implement many other widgets, for example, the Menu Bar, Option Menu, Popup Menu, Pulldown Menu, and Radio Box widgets.

The Frame widget provides a border around objects, and is useful for framing widgets such as the RowColumn which do not provide a border themselves. The Frame sizes itself just big enough to contain any children.

The Paned Window widget imposes a vertical tiling layout policy on child widgets. The width of a Paned Window is taken from the width of the largest child. The heights of individual children can be manipulated by the user using control Sashes provided for the purpose.

The Drawing Area widget is derived from Manager, although in essence it is a free-form widget which can be used for any application purpose. The Drawing Area does not actually perform any drawing itself.

The Scrolled Window widget provides a viewport onto another widget. The viewport can be adjusted using scrollbars provided for the purpose. The Scrolled List and Scrolled Text widgets are derivative of Scrolled Window.

The Main Window widget is also subclassed from Scrolled Window. The widget is intended to provide a standard main application layout. It assumes that the standard main application will consist of menubar, work area, and message area.

The Scale widget is not a general purpose Manager, although it does manage a group of widgets in order to provide a slider object.

Motif also provides some pre-defined managers which form the basis of whole dialogs: the MessageBox, SelectionBox, FileSelectionBox, and Commands widgets.

See also:

- Primitive Widgets
- Bulletin Board widget
- Row Column widget
- Menu widget
- Menu Bar widget
- Option Menu widget
- Radio Box widget
- Scrolled List widget
- Scrolled Text widget
- Scrolled Window widget
- Main Window widget
- Drawing Area widget
- Paned Window widget
- Frame widget
- Scale widget
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