#!/usr/bin/perl -w
use strict;
use diagnostics;

use Gtk2 -init;

my $mw = Gtk2::Window->new();
$mw->signal_connect( 'delete_event' => sub { Gtk2->main_quit; } );

my $button=Gtk2::Button->new_from_stock( 'gtk-add' );

$button->add_events( 'key-press-mask' );
$button->signal_connect(
    'clicked' => sub {
    use Data::Dump;
    my $state = Gtk2->get_current_event->get_state ;
    dd[ @_, $state ];
    dd[ $state->as_arrayref ];
} );

   $mw->add( $button );
   $mw->show_all;
  
   Gtk2->main;
                                      

__END__
[bless(do{\(my $o = 257)}, "Gtk2::Gdk::ModifierType")]



$ perl -MData::Dump -MGtk2 -e " dd [ \%Gtk2::Gdk::ModifierType:: ]
do {
  my $a = [{ ISA => *Gtk2::Gdk::ModifierType::ISA }];
  $a->[0]{ISA} = ["Glib::Flags"];
  $a;
}

$ perl -MData::Dump -MGtk2 -e " dd [ \%Glib::Flags:: ]
do {
  my $a = [
    {
      "(!="         => *Glib::Flags::(!=,
      "(\"\""       => *Glib::Flags::("",
      "(&"          => *Glib::Flags::(&,
      "()"          => *Glib::Flags::(),
      "(*"          => *Glib::Flags::(*,
      "(+"          => *Glib::Flags::(+,
      "(-"          => *Glib::Flags::(-,
      "(/"          => *Glib::Flags::(/,
      "(=="         => *Glib::Flags::(==,
      "(>="         => *Glib::Flags::(>=,
      "(\@{}"       => *Glib::Flags::(@{},
      "(^"          => *Glib::Flags::(^,
      "(bool"       => *Glib::Flags::(bool,
      "(eq"         => *Glib::Flags::(eq,
      "(ne"         => *Glib::Flags::(ne,
      "(|"          => *Glib::Flags::(|,
      "__ANON__"    => *Glib::Flags::__ANON__,
      "all"         => *Glib::Flags::all,
      "as_arrayref" => *Glib::Flags::as_arrayref,
      "BEGIN"       => *Glib::Flags::BEGIN,
      "bool"        => *Glib::Flags::bool,
      "eq"          => *Glib::Flags::eq,
      "ge"          => *Glib::Flags::ge,
      "intersect"   => *Glib::Flags::intersect,
      "ne"          => *Glib::Flags::ne,
      "new"         => *Glib::Flags::new,
      "OVERLOAD"    => *Glib::Flags::OVERLOAD,
      "sub"         => *Glib::Flags::sub,
      "union"       => *Glib::Flags::union,
      "xor"         => *Glib::Flags::xor,
    },
  ];
  $a->[0]{"()"} = \1;
  $a->[0]{"OVERLOAD"} = { dummy => 1 };
  $a;
}


[
  bless({}, "Gtk2::Button"),
  bless(do{\(my $o = 257)}, "Gtk2::Gdk::ModifierType"),
]
[["shift-mask", "button1-mask"]]