GToolBar is the base class for toolbarsThe toolbar is a container, so can have other widgets added to it
as though it were a box container. Buttons should be added as
action items, so that they are rendered in the proper style. Check
buttons should be given the argument use.togglebutton. Use
addSpring to right align items.
passed to constructor
add_gaction_toolitem(obj)Helper to add a gaction item
add_gseparator_toolitem()Helper to add a separator
add_toolbar_items(items)Map a toolbar list, a named list of gaction items or gsepartor items
clear_toolbar()Clear toolbar items
get_widget()What widget do we use for the parent of the children
set_value(value, ...)We can't really adjust spacing between children after they have been positioned.