On Mon, 2011-10-03 at 12:21 +0200, Markus Elfring wrote: > Hello! > > The class "Gtk::CheckButton" provides the feature to display an intermediate > status (by the interface "gtk_toggle_button_set_inconsistent"), doesn't it? > http://developer.gnome.org/gtk3/3.2/GtkToggleButton.html#gtk-toggle-button-set-inconsistent > http://developer.gnome.org/gtkmm/3.2/classGtk_1_1CheckButton.html#_details > > I would like to know the recommend way to represent unknown values for model > attributes when it seems that a member function like > "Gtk::TreeView::append_column" does not support the use of three-valued logic > directly. > http://developer.gnome.org/gtkmm/3.2/classGtk_1_1TreeView.html#a0253a5477ce006bf84fae8eb205efc73 > http://en.wikipedia.org/wiki/Three-valued_logic#Representation_of_values
Maybe you mean the Gtk::TreeView::append_column() method overloads that TreeModelColumn parameters: http://developer.gnome.org/gtkmm/unstable/classGtk_1_1TreeView.html#a0253a5477ce006bf84fae8eb205efc73 That method's documentation mentions that you can instead create the TreeView::Column manually and use TreeViewColumn::set_cell_data_func() with your own callback slot, which you could use to set the "inconsistent" property: http://developer.gnome.org/gtkmm/unstable/classGtk_1_1CellRendererToggle.html#a680f8f0b502d82a6c909aafe90284026 > How do you store a "NULL" (SQL) for a model attribute with a data type like > "bool" and update its visual appearance accordingly? Obviously C++'s bool type can't represent 3 values. You would need something else, I suppose. Personally, I use Gnome::Gda::Value, from libgda, via libgdamm. It's not wonderful, but it works. -- [email protected] www.murrayc.com www.openismus.com _______________________________________________ gtkmm-list mailing list [email protected] http://mail.gnome.org/mailman/listinfo/gtkmm-list
