use Tk;
use Tk::PNG;
use MIME::Base64;

use GD::Graph;
use GD::Graph::bars;

my $data = [
   [qw/1st 2nd 3rd 4th 5th 6th 7th 8th 9th/],
   [qw/  1   2   5   6   3 1.5   1   3   4/],
];

my $graph = GD::Graph::bars->new(400, 300);
$graph->set(
   x_label        => 'X Label',
   y_label        => 'Y label',
   title          => 'Some simple graph',
   y_max_value    => 8,
   y_tick_number  => 8,
   y_label_skip   => 2
) or die $my_graph->error;

my $gd = $graph->plot($data) or die $my_graph->error;

my $mw = MainWindow->new;
my $png = $mw->Photo(-data => encode_base64($gd->png));

$mw->Button( -text => 'doit', -command => sub{
    $data->[ 1 ] = [ map{ rand 5 } 1 .. 9 ];
    undef $graph;
    $graph = GD::Graph::bars->new(400, 300);
    $graph->set(
       x_label        => 'X Label',
       y_label        => 'Y label',
       title          => 'Some simple graph',
       y_max_value    => 8,
       y_tick_number  => 8,
       y_label_skip   => 2
    ) or die $my_graph->error;

    my $gd = $graph->plot($data) or die $my_graph->error;
    $png->blank;
    $png->configure( -data  => encode_base64($gd->png) );
    $mw->update;
} )->pack;

$mw->Label(-image => $png)->pack;

MainLoop;