Group Gtk.RadioToolButtons?

Question

I've been trying for days to find a way to group RadioToolButtons in pygobject without success. There is no *.RadioToolButton.join_group(*) method like RadioButtons.

Here is what I've been trying:

## Toolbar
self.mainWindow.mainBox.mainToolbar = Gtk.Toolbar()
self.mainWindow.mainBox.mainToolbar.get_style_context().add_class(Gtk.STYLE_CLASS_PRIMARY_TOOLBAR)
self.mainWindow.mainBox.mainToolbar.set_style(Gtk.ToolbarStyle.BOTH)
self.mainWindow.mainBox.mainToolbar.radioGroup = list() # *.radioGroup = [] Does not work either.

## Left toolbar separator
self.mainWindow.mainBox.mainToolbar.leftSeparator = Gtk.SeparatorToolItem(draw = False)
self.mainWindow.mainBox.mainToolbar.leftSeparator.set_expand(True)

## Overview toggle button
self.mainWindow.mainBox.mainToolbar.overviewRadio = Gtk.RadioToolButton(Gtk.STOCK_HOME)
self.mainWindow.mainBox.mainToolbar.overviewRadio.set_group(self.mainWindow.mainBox.mainToolbar.radioGroup)
self.mainWindow.mainBox.mainToolbar.overviewRadio.set_is_important(True)
self.mainWindow.mainBox.mainToolbar.overviewRadio.set_label("Overview")
self.mainWindow.mainBox.mainToolbar.overviewRadio.connect("clicked", self.on_overviewRadio_clicked)
self.mainWindow.mainBox.mainToolbar.overviewRadio.set_border_width(4)

## Basic settings toggle button
self.mainWindow.mainBox.mainToolbar.basicRadio = RadioToolButton(Gtk.STOCK_PROPERTIES)
self.mainWindow.mainBox.mainToolbar.basicRadio.set_group(self.mainWindow.mainBox.mainToolbar.radioGroup)
self.mainWindow.mainBox.mainToolbar.basicRadio.set_is_important(True)
self.mainWindow.mainBox.mainToolbar.basicRadio.set_label("Basic")
self.mainWindow.mainBox.mainToolbar.basicRadio.connect("clicked", self.on_basicRadio_clicked)
self.mainWindow.mainBox.mainToolbar.basicRadio.set_border_width(4)

## Right toolbar separator
self.mainWindow.mainBox.mainToolbar.rightSeparator = Gtk.SeparatorToolItem(
    draw = False)
self.mainWindow.mainBox.mainToolbar.rightSeparator.set_expand(True)

(Not all of my code - *.show_all() is not the issue)

Here is what I get:

What am I doing wrong? How can I group these two buttons?

Answer 1

Create the second radio button so it's in the first radio button's group using:

Gtk.RadioToolButton.new_with_stock_from_widget(first_button, Gtk.STOCK_PROPERTIES)

PS. Looks like the UI task you are trying to accomplish might be better done with a Notebook?