use strict;
use Tk;

use Data::Dumper;

my @data = (qw( ccc eee ddd aaa aaa ccc ddd ddd bbb ddd eee ggg fff));
my %seen;

# Create & configure text widget...
my $top = MainWindow->new;
my $list = $top->Scrolled('Listbox')->
	pack(-side=>'right', -fill=>'both', -expand =>1);

my $ref;
$ref = $top->repeat(700, \&addItem);

sub addItem
{
	my $item = shift(@data);
	if(!$item) { $ref->cancel; return };
	print STDERR "$item\n";
        # Selected items (by name)
        my @selected_items = map {$list->get($_)} $list->curselection;
        print "Selected items: @selected_items\n";
	if(! $seen{$item}) {
        my @new_selection_order = sort keys %seen;
        # Map names to list position
        my %new_selection = map {($new_selection_order[$_] => $_)} 0..$#new_selection_order;
	   $list->delete(0, 'end');
	   $list->insert('end', @new_selection_order);
           # Set selection(s)
           print "New indexes should be @new_selection{@selected_items}\n";
           $list->selectionSet($_) for @new_selection{@selected_items};
	}
	$seen{$item}++;
}

MainLoop();