use strict;
use warnings;
use Tk;
use Data::Dumper;
my $mw = tkinit;

my $getter = sub{ $_[0]->Subwidget('entry')->get};
my $setter = sub{my $e = $_[0]->Subwidget('entry');
                 $e->delete(0,'end');
                 $e->insert('end', $_[1]);
             };
my $inst = sub{$_[0]->bind('<Key-Return>' ,$_[1]);
               $_[0]->configure(-browsecmd => $_[1]);
           };
my $mbe;
$mbe = $mw->EntrySet(-entryclass   => 'BrowseEntry',
                     -getter       => $getter,
                     -valuelist => [],
                     # -entryoptions => [-choices => []],
                     -setter       => $setter,
                     -callback_installer => $inst,
                     -changed_command => sub{mbe_changed( $mbe )},
                 )->pack(-fill => 'both',
                         -expand => 1);
$mw->Button(-text => 'dump value',
            -command => sub{print Dumper $mbe->valuelist},
            )->pack;
MainLoop;

{
    my  @choices;
    sub mbe_changed{
        my $mbe = shift;
        my %seen;
        my @valuelist = @{$mbe->valuelist};
        for my $item ( @choices, @valuelist) {
            $seen{ $item } = 1;
        }
        @choices = sort keys %seen;
        my @e = (@{$mbe->{_EntrySet}{entry_pool}},
                 @{$mbe->{_EntrySet}{entries}});
        for my $entry ( @e ) {
            $entry->configure(-choices => \@choices);
        }
        $mbe->valuelist(\@valuelist);
    }
}