Editable toggle when multiple model cols in view col

[Edd Dawson <edd nunswithguns net>]

Hello all,

The first column of my TreeView displays two columns from my TreeStore model: a 
bool/toggle and a string.

I would like the toggle to be editable, but not the adjacent string. I'm 
struggling to implement this behavior.

Here's what I have at the moment:

----------------------
// Create a view column that contains a check-box and some text
Gtk::TreeView::Column* joint_column =
	Gtk::manage(new Gtk::TreeView::Column("Fixture"));

joint_column->pack_start(fixtures_record_.get<1>(), false);
joint_column->pack_start(fixtures_record_.get<0>());
		
// Add it to the TreeView
fixtures_view_.append_column(*joint_column);

// Make it editable
Gtk::TreeViewColumn *col = fixtures_view_.get_column(0);
Gtk::CellRendererToggle *rend =
	dynamic_cast<Gtk::CellRendererToggle *>(col->get_first_cell_renderer());
			
assert(rend);
rend->property_mode() = Gtk::CELL_RENDERER_MODE_EDITABLE;
col->add_attribute(rend->property_activatable(), fixtures_record_.get<6>());
----------------------

Here, fixtures_record_ is an object of type derived from 
Gtk::TreeModel::ColumnRecord and each of its get<N>() member functions returns a 
Gtk::TreeModelColumn<T> for some appropriate T; get<0>() returns a 
TreeModelColumn<string>, get<1>() a TreeModelColumn<bool>, and get<6>() a 
TreeModelColumn<bool>.

All cells in column 6 are set to 'true'.

I believe the last two lines are in error, but I don't know how or why.

The book (http://www.gtkmm.org/docs/gtkmm-2.4/docs/tutorial/html/ch08s02.html) says:

"You must set the cell's editable property to true, like so:

cell.property_editable() = true;"

but I can't work out what kind of object 'cell' is, here. CellRendererText has a 
property_editable() function, but CellRendererToggle hasn't and nor have any of 
its bases.

Any help is very much appreciated!

Kind regards,

Edd