gtkmm: New API in gtkmm 3.2

gtkmm 4.7.1

New API in gtkmm 3.2

Class Gtk::FontChooser
Class Gtk::FontChooserDialog
Class Gtk::FontChooserWidget
Member Gtk::Scale::Scale (Orientation orientation)
Member Gtk::Tooltip::unset_custom ()
Member Gtk::Tooltip::unset_icon ()
Member Gtk::Tooltip::unset_markup ()
Member Gtk::Tooltip::unset_text ()
Member Gtk::TreeView::unset_drag_dest_row ()
Member Gtk::TreeView::unset_row_separator_func ()