Re: Switch a CellRendererCombo's model

[muppet <scott asofyet org>]

On Jul 7, 2005, at 12:59 AM, Daniel Kasak wrote:

> My main TreeStore has a column at the end ( 1 from the end anyway )
> that's defined as a Gtk2::ListStore ( I've also tried with a
> Glib::Scalar ). I'm not sure if either of these are correct.

Gtk2::ListStore is the best; Gtk2::TreeModel and Glib::Object would  
also probably work, but ListStore is specific enough to ensure that  
the wrong type of object doesn't wind up in the column.

Glib::Scalar is not correct; that's basically "typeless" from gtk+'s  
point of view.  It's useful if you're using a cell data function with  
a native perl data structure.


>     $self->{columns}[$column_no] =
> Gtk2::TreeViewColumn->new_with_attributes(
>                                             $field->{name},
>                                             $renderer,
>                                             text    => $column_no,
>                                             model   =>  
> $column_no_of_model,
>                                         );
...
> When the main TreeStore is populated and gets rendered, I get a  
> string of:
>
> GLib-GObject-WARNING **: unable to set property `model' of type
> `GtkTreeModel' from value of type `gint'

That means you're using the wrong column number in  
$column_no_of_model, and the TreeViewColumn is trying to set the  
CellRendererCombo's "model" property from a value containing an  
integer, which it fetched from a TreeStore column containing an integer.


Here's a simple working example, maybe it will be better than trying  
to explain in prose:


#!/usr/bin/perl -w
use strict;
use Gtk2 -init;
use Glib ':constants';

#
# create a bunch of models to hold the appropriate choices for the  
various rows
#
my @combo_models;
foreach my $data ([qw(one two three four five)],
                  [qw(red orange yellow green blue indigo violet)],
                  [qw(george john paul ringo)],
                  [qw(north south east west)]) {
    my $model = Gtk2::ListStore->new (qw(Glib::String));
    foreach my $string (@$data) {
        $model->set ($model->append, 0, $string);
    }
    push @combo_models, $model;
}

#
# create and populate the main list
#
use constant NAME_COLUMN => 0;
use constant CURRENT_COLUMN => 1;
use constant MODEL_COLUMN => 2;
my @column_types;
$column_types[NAME_COLUMN] = 'Glib::String';
$column_types[CURRENT_COLUMN] = 'Glib::String';
$column_types[MODEL_COLUMN] = 'Gtk2::ListStore';
my $model = Gtk2::ListStore->new (@column_types);
foreach my $data (
    { name => 'Fred', current => 1, model => $combo_models[0] },
    { name => 'Barney', current => 2, model => $combo_models[1] },
    { name => 'Wilma', current => 3, model => $combo_models[2] },
    { name => 'Betty', current => 0, model => $combo_models[3] },
    { name => 'Pebbles', current => 2, model => $combo_models[0] },
    { name => 'Bam-Bam', current => 3, model => $combo_models[1] },
) {
    $data->{current} =
            $data->{model}->get
                ($data->{model}->iter_nth_child (undef, $data-> 
{current}), 0);
    $model->set ($model->append,
                 NAME_COLUMN, $data->{name},
                 CURRENT_COLUMN, $data->{current},
                 MODEL_COLUMN, $data->{model});
}

#
# create a view for that model.
#
my $treeview = Gtk2::TreeView->new ($model);

$treeview->insert_column_with_attributes
        (-1, 'Name', Gtk2::CellRendererText->new, text => NAME_COLUMN);

my $combo_renderer = Gtk2::CellRendererCombo->new;
$combo_renderer->set (text_column => 0, # col in combo model with  
text to display
                      editable => TRUE); # without this, it's just a  
text renderer
$combo_renderer->signal_connect (edited => sub {
        my ($cell, $text_path, $new_text) = @_;
        $model->set ($model->get_iter_from_string ($text_path),
                     CURRENT_COLUMN, $new_text);
});
$treeview->insert_column_with_attributes
        (-1, 'Selection', $combo_renderer,
         text => CURRENT_COLUMN, model => MODEL_COLUMN);

#
# put all that on the screen
#
my $window = Gtk2::Window->new;
$window->signal_connect (destroy => sub { Gtk2->main_quit });
$window->add ($treeview);
$window->show_all;
Gtk2->main;



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stop thinking about new ways to harm our country and our people, and  
neither do we.
  -- President George W. Bush