use strict;
use warnings;
use Tk;
use Tk::Tree;
use Tk::Balloon;

my $mw = MainWindow->new();
my $h = $mw->Scrolled('Tree', -scrollbars=>'ose', -selectmode=>'extended')->pack(-side=>'top', -fill=>'both', -expand=>1);
my %help;
for my $top (1..3) {
    $h->add($top, -text=>$top);
    for (1..3) {
        $h->add("$top.$_", -text=>"$top.$_");
        $help{"top.$_"} = "help_$top.$_";
    }
}

my $b = $mw->Balloon(-initwait=>0);
$b->attach($h->Subwidget('scrolled'), -balloonposition=>'mouse', -msg=>\%help);
MainLoop();