#!/usr/bin/perl -w

use strict;
use Tk;

my $x = '12.0';
my $y = '14.0';
my $scale = '22.5';
my $xmax = $x * $scale;
my $ymax = $y * $scale;
my $shouldBe = sprintf("Originally X=%4.1f, Y=%4.1f, scale=%4.1f X-max=%8.4f, Y-Max=%8.4f",$x,$y,$scale,$xmax,$ymax);
my $results;

my $mw = MainWindow->new;

my $InFrame = $mw->Frame()->pack(-side=>'top');
   $InFrame->Label(-text=>"X= ")->pack(-side=>'left');
   $InFrame->Entry(-textvariable=>\$x)->pack(-side=>'left');
   $InFrame->Label(-text=>" Y= ")->pack(-side=>'left');
   $InFrame->Entry(-textvariable=>\$y)->pack(-side=>'left');
   $InFrame->Label(-text=>"Scale= ")->pack(-side=>'left');
   $InFrame->Entry(-textvariable=>\$scale)->pack(-side=>'left');

my $OutFrame = $mw->Frame()->pack(-side=>'top');
   $OutFrame->Label(-textvariable=>\$results)->pack(-side=>'top');
   $OutFrame->Label(-textvariable=>\$shouldBe)->pack(-side=>'top');

$mw->bind("<Key-KP_Enter>",\&calc);
$mw->bind("<Key-Return>",\&calc);

calc();
MainLoop;

sub calc {
  $xmax = $x * $scale;
  $ymax = $y * $scale;
  $results = sprintf("Calculated X-max=%8.4f, Y-Max=%8.4f",$xmax,$ymax);
  print "$x, $y, $scale, $xmax, $ymax\n";
}