The #GtkHandleBox widget allows a portion of a window to be "torn off". It is a bin widget which displays its child and a handle that the user can drag to tear off a separate window (the “float window”) containing the child widget. A thin “ghost” is drawn in the original location of the handlebox. By dragging the separate window back to its original location, it can be reattached.
Fluent builder for gtk.handle_box.HandleBox
Fluent builder implementation template for gtk.handle_box.HandleBox
Module for HandleBox class