#!/usr/bin/perl
use strict;
use Tk;

our ($goMainWindow);
our (%ghGuiObjs);
our (%ghGuiCBVars);

$| = 1;
&main();

sub main {
  buildGui();
  MainLoop;
} #end sub main

sub updateA {
  if ( $ghGuiCBVars{"nEnableFrameA"} == 1 ) {
    $ghGuiObjs{"oContainerA"}->pack();
  } else {
    $ghGuiObjs{"oContainerA"}->packForget();
  }
}

sub updateB {
  if ( $ghGuiCBVars{"nEnableFrameB"} == 1 ) {
    $ghGuiObjs{"oContainerB"}->pack();
  } else {
    $ghGuiObjs{"oContainerB"}->packForget();
  }
}

sub buildGui {
  $goMainWindow = new MainWindow;

  my ($oLabel) = $goMainWindow->Label(
                      -text => "This is my example",
                      )->pack(
                      -padx => '5',
                      -pady => '5',
                      -expand => '1',
                      -fill => 'x',
                      );
  my ($oCbA) = $goMainWindow->Checkbutton(
                      -text => 'Enable A',
                      -variable => \$ghGuiCBVars{"nEnableFrameA"},
                      -command => \&updateA,
                      -anchor => 'w',
                     );
  $ghGuiCBVars{"nEnableFrameA"} = 1;
  my ($oFrameA) = $goMainWindow->Labelframe(
                      -labelwidget => $oCbA,
                      )->pack(
                      -padx => '5',
                      -expand => '1',
                      -fill => 'both',
                      );
  my ($oContainerFrameA) = $oFrameA->Frame(
                      )->pack(
                      -expand => '1',
                      -fill => 'both',
                      -pady => '5',
                      );
  $ghGuiObjs{"oContainerA"} = $oContainerFrameA;
  my ($oLbA) = $oContainerFrameA->Listbox(
                      -relief => 'groove',
                      -borderwidth => '5',
                      -height => '5',
                      )->pack(
                      -fill => 'both',
                      -expand => '1',
                      );


  my ($oCbB) = $goMainWindow->Checkbutton(
                      -text => 'Enable B',
                      -variable => \$ghGuiCBVars{"nEnableFrameB"},
                      -command => \&updateB,
                      -anchor => 'w',
                     );
  $ghGuiCBVars{"nEnableFrameB"} = 1;
  my ($oFrameB) = $goMainWindow->Labelframe(
                      -labelwidget => $oCbB,
                      )->pack(
                      -padx => '5',
                      -expand => '1',
                      -fill => 'both',
                      );
  my ($oContainerFrameB) = $oFrameB->Frame(
                      )->pack(
                      -expand => '1',
                      -fill => 'both',
                      -pady => '5',
                      );
  $ghGuiObjs{"oContainerB"} = $oContainerFrameB;
  my ($oLbB) = $oContainerFrameB->Listbox(
                      -relief => 'groove',
                      -borderwidth => '5',
                      -height => '5',
                      )->pack(
                      -fill => 'both',
                      -expand => '1',
                      );

  my ($oExit) = $goMainWindow->Button(-text => 'Exit',
                      -command => sub{exit},
                     )->pack(
                      -padx => '5',
                      -pady => '5',
                      -side => 'bottom',
                     );

}