Re: Adding a customer cell renderer to a simplelist

[muppet <scott asofyet org>]

On Aug 29, 2004, at 8:15 PM, Daniel Kasak wrote:

> I'm a little unsure of how the columns are numbered ( whether hidden 
> columns count or not ).

SimpleList is designed to keep things Simple by maintaining a 
one-to-one relationship between the columns of the model and the 
columns of the view.  'hidden' columns are a bit of a hack; they are 
simply skipped when iterating over the column info to create view 
columns.  to that end i usually try to keep the hidden columns at the 
end of the model so the view and model column indices still line up 
properly.


> I started out by assuming that they *do* count, so I used:
>
> >     my $renderer = Gtk2::CellRendererSpinButton->new();
...
> >        $column = Gtk2::TreeViewColumn->new_with_attributes(
> >                                                             
> > "Postcode",
> >                                                             $renderer,
> >                                                             value   
> > => 6

index 6 refers to the 7th column.  your model has only 6 columns.

> >                                                        );



> It still doesn't seem like my new column is being 'registered' as far 
> as the SimpleList is concerned...

i think you're still confusing the model columns and view columns.  
you've created another column in the view, but the model has not 
changed.

most importantly, $treeview->append ($column) does not affect your 
model, it only adds another element to the display.  that view column 
can display data from any of the model columns.


> I've just had an idea now: am I supposed to have *another* column with 
> the value to be used for the custom cellrenderer to look at ( ie am I 
> supposed to define the 'PostCode' column when I first create the 
> SimpleList and then just set it's width to zero? )?

that's a thought in the right direction, as it will put another column 
into your model.

i suggest, however, you try a more elegant approach to get SimpleList 
to do the work for you:

  # add a new column type that uses a CellRendererSpinButton
  # to display and edit a Glib::Double column
  Gtk2::SimpleList->add_column_type (
                'number',
                type => 'Glib::Double',
                renderer => 'Gtk2::CellRendererSpinButton',
                attr => 'value',
  );

  my $slist = Gtk2::SimpleList->new_from_treeview(
                $prospects->get_widget('Locations_SList'),
                'DanPK'             => 'hidden',
                'LocNo'             => 'hidden',
                'Branch Name'       => 'text',
                'Address'           => 'text',
                'Suburb'            => 'text',
                'State'             => 'text'
                'PostCode'          => 'number'
  );

  # simplelist's set_column_editable() method doesn't know
  # how to handle a 'number' column, so we have to do
  # this one by hand.  note that it's the 7th column in the
  # model, but the *5th* column in the view, so its index
  # is 4.  (this confusion is why i like to keep the hidden
  # columns last.)
  my $numbercell = ($slist->get_column (4)->get_cell_renderers)[0];
  # tell it to allow editing...
  $numbercell->set (mode => "editable");
  # ... and hook up something to handle that editing.
  $numbercell->signal_connect (edited => sub {
        my (undef, $pathstring, $newval) = @_;
        # we'll cheat and use the path string as a stringified row number.
        $slist->{data}[$pathstring+0][2] = $newval;
  });


having said all that, of course, i don't think a double is what you 
want to use to represent postal codes.  you may need to hack up the 
CellRenderer to use an integer instead of a double.


--
"that's it! you're a genius!"  "yes.  that's what i think.  do you 
think i deserve a raise?"
        - dialogue from 'Godzilla versus Mothra', 1964