#!/usr/bin/perl --
use strict;
use warnings;
use Tk;
use Tk::WidgetDump;
my $mw = Tk::MainWindow->new;
my $fs = $mw->FileSelect( -font => "Arial 24" );
FontForKids( $mw , "Arial 24" );
$mw->WidgetDump; 
$fs->Show;
sub FontForKids {
    my( $mw , $font ) = @_;
    my @kids = $mw->children ;
    while( @kids ){
        my $kid = shift @kids;
        push @kids, $kid->children;
        eval { $kid->configure( -font => $font ); 1 }
##        or warn $@;
    }
    return $mw;
}