A container with just one child

The Bin widget is a container with just one child. It is not very useful itself, but it is useful for deriving subclasses, since it provides common code needed for handling a single child widget.

Many Gtk+ widgets are subclasses of Bin, including Window, Button, Frame, HandleBox, and ScrolledWindow.

| GObject
| +----Object
| +----Widget
| +----Container
| +----Bin
| +----Window
| +----Alignment
| +----Frame
| +----Button
| +----Item
| +----ComboBox
| +----EventBox
| +----Expander
| +----HandleBox
| +----ToolItem
| +----ScrolledWindow
| +----Viewport