se warnings;
use strict;
use Tk;

my $mw = MainWindow->new();
$mw->configure(-title=> "Some Title");
$mw->minsize(qw(700 200));

my $mainDataFrame = $mw->Frame()->pack(-side=>'top', -fill=>'x');
my $labelFrame = $mainDataFrame->Frame->pack(-side=>'left');
my $dataEntryFrame = $mainDataFrame->Frame->pack(-side=>'left');
my $unitsFrame = $mainDataFrame->Frame->pack(-side=>'left');

my $refreshRate;
my $spectralRes;
my $showSpectrumHz;

my @tableConfig = ( ['Refresh rate:','60',\$refreshRate,'FPS'],
                    ["Spectral resolution",'10',\$spectralRes,'Hz'],
                    ["Show spectrum up to",'5000',\$showSpectrumHz,'Hz']);
               
for my $rowRef ( @tableConfig )
{
    $labelFrame->Label(-text => "$rowRef->[0]",
                       -anchor=>'e',
                       -justify => 'right')->pack(-side=>'top', -fill => 'x');
    
    my $dataRef = $rowRef->[2]; # put default value into textvariable
    $$dataRef   = $rowRef->[1];
    $dataEntryFrame->Entry(-width => 8,
                           -textvariable => $dataRef,
                           )->pack(-side =>'top', -fill => 'x');
   
    $unitsFrame->Label(-text => "$rowRef->[3]",
                       -anchor=>'w',
                       -justify => 'left')->pack(-side=>'top', -fill => 'x');
}

MainLoop();