def create_frame(title)
frame = Gtk::Frame.new(title)
hbox = Gtk::HBox.new(false, 8)
hbox.set_border_width(8)
frame.add(hbox)
scrollwin = Gtk::ScrolledWindow.new
scrollwin.set_policy(Gtk::POLICY_NEVER, Gtk::POLICY_AUTOMATIC)
scrollwin.shadow_type = Gtk::SHADOW_IN
hbox.pack_start(scrollwin, true, true)
tree_view = Gtk::TreeView.new
tree_view.headers_visible = false
scrollwin.add(tree_view)
selection = tree_view.selection
selection.mode = Gtk::SELECTION_BROWSE
button_vbox = Gtk::VBox.new(false, 5)
hbox.pack_start(button_vbox, false, false)
@size_group.add_widget(button_vbox)
return frame, tree_view, button_vbox
end