CellRendererToggle.setRadio

If radio is true, the cell renderer renders a radio toggle (i.e. a toggle in a group of mutually-exclusive toggles). If false, it renders a check toggle (a standalone boolean option). This can be set globally for the cell renderer, or changed just before rendering each cell in the model (for #GtkTreeView, you set up a per-row setting using #GtkTreeViewColumn to associate model columns with cell renderer properties).