Re: Gtk::TreeView cell background color

[Jonathon Jongsma <jonathon jongsma gmail com>]

On 11/29/05, Jason Burchfield <jason burchfield cas-inc com> wrote:
> When I add a Gtk::TreeModelColumn<bool>, which uses a
> Gtk::CellRendererToggle, to a Gtk::TreeView and try to change the cell
> color I get a seg fault.
> Is this a bug or am I doing something wrong.  All other columns work...

I'm not an expert, but I did successfully get a treeview to use
different background colors as follows.  I'll show you how I did it in
just a second, but first note that if you're just trying to alternate
colors, you may want to take a look at the
Gtk::TreeView::set_rules_hint() function
(http://gtkmm.org/docs/gtkmm-2.4/docs/reference/html/classGtk_1_1TreeView.html#a115).

Anyway, this is how I did it. I'm not sure it's the best way, but it
seemed to work.  I derived my own class from a Gtk::TreeView (called
BookmarkList) and added a single column to it that contained a string
representation of a color (e.g. #FFFFFF).  This string was supposed to
be used to set the background color of the cell.  The constructor was
as follows:

        BookmarkList::BookmarkList(void)
            : m_refListStore(Gtk::ListStore::create(m_columns))
        {
            set_model(m_refListStore);

            // Display string representation of the color
            append_column("Favorites", m_columns.m_colText);

            // set a function to call when the data for a particular value is
            // set so that we can use the information to set the background
            // color of the cell
            get_column(0)->set_cell_data_func(*get_column_cell_renderer(0),
                    sigc::mem_fun(*this, &BookmarkList::set_cell_background));

            // display column headers
            set_headers_visible(true);
        }

The important part being the set_cell_data_func call.  This function
specifies a callback function that will set the color for each cell. 
The function was defined as follows:

        void BookmarkList::set_cell_background(Gtk::CellRenderer* cell,
                const Gtk::TreeModel::iterator& iter)
        {
            // set the background color equal to the value of the hexstring
            cell->property_cell_background() = (*iter)[m_columns.m_colText];
        }

Hope that helps.
Jonathon