-selectmode => 'multiple' only allows for contiguous selection, via click&drag or click&shift-click.

-selectmode => 'extended' allows for all that, plus non-contiguous selection, via ctrl-click.

Here is an example that will demonstrate the differences: 

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

my $mw = MainWindow->new();

my $hlist = $mw->HList(
  -itemtype   => 'text',
#  -selectmode => 'multiple',
  -selectmode => 'extended',
  -browsecmd  => \&bc,
);
my $text = $mw->Text();

my @words = qw(
  aback  abaft  abandon
  babble babies baboon
  cabal  cabana cabaret
);

$hlist->add($_, -text=>$_) foreach qw(a b c);
foreach ( @words ) {
  my $first = substr($_, 0, 1);
  $hlist->add("$first.$_", -text=>$_);
}

$hlist->pack(-side => 'top',    -fill => 'both', -expand => 1);
$text ->pack(-side => 'bottom', -fill => 'both', -expand => 1);

MainLoop;

sub bc {
  my $sel = join "\n", $hlist->infoSelection();
  $text->delete('1.0', 'end');
  $text->insert('end', $sel);
}

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In reply to Re: multiple selection in a Perl/Tk HList by Util
in thread multiple selection in a Perl/Tk HList by Real Perl

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