The Gnome.DockLayout widget is meant to make it simple for
programmers to handle the layout of a GnomeDock widget.
Gnome.DockLayout can contain an arbitrary number of W(Gnome.DockItem)
widgets, each of them with its own placement information. It is
possible to "extract" a layout from an existing W(GnomeDock)
widget, as well as adding the items present in a Gnome.DockLayout
to it. Moreover, Gnome.DockLayout is able to create a layout
configuration string that can be later used to re-construct the
layout on a brand new Gnome.DockLayout widget.
As a consequence, Gnome.DockLayout is very useful to save and
retrieve W(GnomeDock) configurations into files. For example,
W(GnomeApp) uses Gnome.DockLayout to create a default layout
configuration, override it with the user-specific configuration
file, and finally apply it to it's W(GnomeDock).
Gnome.DockItem()->set_shadow_type()