use strict;
use warnings;

use Tk;
use Tk::Pane;

my $mw = MainWindow->new;
my($create_fields_num)=5;
my($paned_win) = $mw->Panedwindow(-showhandle => 1);
$paned_win->pack(-side => 'top', -expand => 1, -fill => 'both');

my($l_pane) = $paned_win->Scrolled('Pane', 
	-scrollbars => 'osoe',
	-sticky => 'new'
)->pack(-side => 'top', -anchor => 'nw', -expand => 1, -fill => 'both');

my($lab_entry) = $l_pane->LabEntry(
	-label => "Enter Num:",
	-labelPack    => [-side => 'left', -anchor => 'w'],
	-textvariable => \$create_fields_num
)->pack(-side => 'top', -anchor => 'n', -fill => 'x');
$l_pane->Button(
	-text => 'Create Fields',
	-command => [\&create_fields, $l_pane, $paned_win, \$create_fields_num]
)->pack(-side => 'top', -anchor => 'n', -fill => 'x');

my($r_pane) = $paned_win->Scrolled('Pane', 
	-scrollbars => 'osoe',
	-sticky => 'new'
)->pack(-side => 'top', -anchor => 'nw', -expand => 1, -fill => 'both');

$paned_win->add($l_pane, $r_pane);
MainLoop;

sub create_fields{
	my($l_pane, $paned_win, $fields) = @_;
	my($sub_frame) = $l_pane->Frame;
	foreach(@{$sub_frame->configure}){
		print join(" ", @{$_}, "\n");
	}
	for(my $field_num=0; $field_num < $$fields; $field_num++){
		$l_pane->Entry()->pack(-side => 'left');

	}
	
	# Move the sash to accommodate the new fields
	$mw->after(30, sub{
		my($xscrollbar, $yscrollbar, $bar_width, $bar_visible);
		foreach(@{$l_pane->children()}){
			if($_->name eq 'scrollbar'){
				$xscrollbar = $_;
			}
			if($_->name eq 'ysbslice'){
				$yscrollbar = $_;
			}
		}
		
		if($xscrollbar->ismapped){
			my($bar_width) = $xscrollbar->width;
			my($xscrollbar_height)= $xscrollbar->height;
			my($yscrollbar_width) = $yscrollbar->width;
			my(undef, $visible_fraction) = $l_pane->xview;
			my($x, $y) = $paned_win->sash(coord  => 0);

			my($width) =  ($bar_width/$visible_fraction)+$xscrollbar_height;

			if($yscrollbar->ismapped){
				$width = $width+$yscrollbar_width;
			}

			if($xscrollbar->ismapped){
				$paned_win->sash( place => 0, $width , $y);
			}
		}
	});
}