#!/usr/bin/perl
# Multiple Widgets with one scrollbar.pl

use Tk;
require Tk::Pane;


$mw = MainWindow->new();
$mw->title("One Scrollbar/Three Listboxes");
$mw->Button(-text => "Exit",
			-command => sub { exit })->pack(-side => 'bottom');
	
$scroll =$mw->Scrollbar();

# Anonymous array of the three Listboxes
$listboxes = [ $mw->Scrolled(Pane, -scrollbars => 'ose', 
							-sticky => 'nsew', -background => 'green'),
				$mw->Scrolled(Pane, -scrollbars => 'ose', 
							-sticky => 'nsew', -background => 'blue'),
				$mw->Scrolled(Pane, -scrollbars => 'ose', 
							-sticky => 'nsew', -background => 'cyan') ];

# This method is called when on Listbox is scrolled with the keyboard
# It makes the Scrollbar reflect the chang, and scrolls the other lists
sub scroll_listboxes {
	my ($sb, $scrolled, $lbs, @args) = @_;
	$sb->set(@args); # tell the Scrollbar what to display
	my ($top, $bottom) = $scrolled->yview();
	foreach $list (@$lbs) {
	$list->yviewMoveto($top); # adjust each lb
	}
}

# Configure each Listbox to call &scroll_listboxes
foreach $list (@$listboxes) {
	$list->configure(-yscrollcommand => 
						[ \&scroll_listboxes, $scroll,
							$list, $listboxes ] ); }

										
# Configure the Scrollbar to scroll each Listbox
$scroll->configure(-command =>sub { foreach $list (@$listboxes) {
											$list->yview(@_);
										}});
										
# Pack the Scrollbar and Listboxes
$index = 0;
$scroll->pack(-side => 'left', -fill => 'y');
foreach $list (@$listboxes) {
		$list->pack(-side => 'left');
		$list->Label(-text => "One")->pack();		
		$list->Label(-text => "Two")->pack();
		$list->Label(-text => "Three")->pack();
		$list->Label(-text => "Four")->pack();
		$list->Label(-text => "Five")->pack();		
		$list->Label(-text => "Six")->pack();
		$list->Label(-text => "Seven")->pack();
		$list->Label(-text => "Eight")->pack();	
		$list->Button(-text => "$index", -command => sub { exit})->pack();	
		$index++;
}

MainLoop;