#!/usr/bin/perl
use warnings;
use strict;
use Tk;

my $mw   = MainWindow->new();

my @list = qw/alpha beta charlie delta echo foxtrot golf hotel
     india juliet kilo lima motel nancy oscar papa quebec radio sierra
        tango uniform victor whiskey xray yankee zulu/;

my $sl   = $mw->Scrolled('Listbox',
    -takefocus        => 1,
    -height           => 5,
    -width            => 10,
    -selectmode       => "single",
    -selectbackground => 'YELLOW',
    -selectforeground => 'black'
)->pack;
$sl->insert( 0, @list );
$sl->bind( '<KeyPress>', [ \&FindEntry, Ev('A') ] );
$sl->focus;

MainLoop;

sub FindEntry {
    my ( $sl, $key ) = @_;
    print "findEntry called\n";
    $sl->selectionClear( 0, 'end' );
    return unless $key =~ /\w/;
    foreach my $i ( 0 .. ( @list - 1 ) ) {
        if ( $list[$i] =~ /^$key/ ) {
            $sl->selectionSet($i);
            $sl->see($i);
        }
    }
}