#!/usr/bin/perl
use warnings;
use strict;
use Gtk2 -init;
use Gnome2::Wnck;

# section to get all windows
my @gdk;
my $s = Gtk2::Gdk::Screen->get_default;
my $gdkwindow = $s->get_root_window;
my ($x0, $y0, $width0, $height0, $depth) = $gdkwindow->get_geometry;
#print "geometry x0->$x0, y0->$y0, width->$width0, height->$height0, depth->$depth\n";

my $screen = Gnome2::Wnck::Screen->get_default;
$screen->force_update;
my @windows = $screen->get_windows;

foreach my $fwin (@windows) {
        push @gdk, Gtk2::Gdk::Window->foreign_new($fwin->get_xid);
      }
########################

###  control window section with a global grab  ############
my $password= 'q';
my $message="Type $password then enter to quit";
my $typed="";
my $gdkwin;

my $mw  = new Gtk2::Window('popup');
$mw->set_position('center'); # see below for invisible window

my $vbox = Gtk2::VBox->new(0,5);
$mw->add($vbox);

my $msg_w_markup = Gtk2::Label->new();
$msg_w_markup->set_justify('left'); 
$msg_w_markup->set_markup("
<span background = 'black' foreground= 'green' size ='30000'> <i>$message</i></span>");
$vbox->pack_start($msg_w_markup,0,0,4);	

my $typed_w_markup = Gtk2::Label->new();
$typed_w_markup->set_justify('left'); 
$typed_w_markup->set_alignment(0, 0.5);
$typed_w_markup->set_markup("
<span background = 'black' foreground= 'red' size ='30000'>$typed</span>");
$vbox->pack_start($typed_w_markup,0,0,4);	

$mw->add_events( [ qw(key_press_mask) ]);
$mw->signal_connect('key_press_event', \&do_keypress);

# if you don't want someone to see password window, 
# just move it out of sight :-)
# $mw->signal_connect('realize', sub { $mw->window->move(2000,2000); });

# must define gdkwin after it is mapped
$mw->signal_connect('map', sub { $gdkwin = $mw->window ; do_grab(); });
$mw->show_all;

#  make the jumping occur
my $timer = Glib::Timeout->add (100, \&jump );
Gtk2->main;

sub do_grab(){
  my $grabstatus= Gtk2::Gdk->keyboard_grab(
        $gdkwin, 1 ,Gtk2::Gdk::X11->get_server_time($gdkwin) );
    if($grabstatus ne "success"){
      $msg_w_markup->set_text("keyboard grab failed");
    }
}

sub do_ungrab()
{
  Gtk2::Gdk->keyboard_ungrab(Gtk2::Gdk::X11->get_server_time($gdkwin));
}

sub do_keypress(@)
{
  my ($widget,$event)=@_;
  my $kv = $event->keyval;
  my $kn = Gtk2::Gdk->keyval_name($kv);

  if($kn =~ /Return|Enter/){

      if($typed eq $password) {
            do_ungrab();
            Gtk2->main_quit;
       }else{
          $typed="";
    }
  
  }elsif(length($kn) == 1 && $kn =~ /[[:print:]]/){
    $typed .= $kn;
  }

   my $showtyped=$typed;
  
   if(length($showtyped) > 30){
      $showtyped=substr($showtyped,0,30);
    }
   
   $typed_w_markup->set_markup("
    <span background = 'black' foreground= 'red' size ='30000'> <i>$showtyped</i></span>");
}
#####################################
sub jump{

  foreach( @gdk){ 
#   print "$_\n";
    my $xd = rand $width0/2;
    my $yd = rand $height0/2;
    $_->move($xd,$yd) 
   } 

Gtk2->main_iteration while Gtk2->events_pending;
return 1;
}