The contents of a handle box can be 'dragged' out of the box by the user.
The contents will then be placed in a separate window.
GTK2.HandleBox()->add(GTK2.Label("The contents"))
Properties:
int handle-position
int shadow
int shadow-type
int snap-edge
int snap-edge-set
Signals:
child_attached
Called when a new child is added to the box
child_detached
Called when a child is removed from the box
GTK2.HScrollbar()->create()