#!/usr/bin/perl
######################################################################
#  An example of how to get rgb value in a motion callback of
#  the image shown in Gtk2::Image.
#
#  Dov Grobgeld <dov.grobgeld@gmail.com>
#  2005-08-28
#
#  This code is in the public domain.
######################################################################

use strict;
use Gtk2 '-init';

sub get_rgb {
  my($img, $x,$y) = @_;
  return unpack("C3", $img->new_subpixbuf($x,$y,1,1)->get_pixels());
}

sub cb_image_motion {
 my ($this, $event, $user_data) = @_;
 my ($label, $pb) = @$user_data;
 my $x = $event->x;
 my $y = $event->y;

 my $info = sprintf("Coord: (%3d,%3d)   rgb: (%3d,%3d,%3d)",$x,$y,
            get_rgb($pb, $x,$y));

 $label->set(label=>$info);
 return 1;
}

sub create_widgets {
  my $filename = shift || 'bridget-1.jpg';
  my $mw = Gtk2::Window->new();
  $mw->signal_connect (delete_event => sub {Gtk2->main_quit;});

  # create a vbox for the image and a label
  my $vbox = Gtk2::VBox->new();
  $mw->add($vbox);

# Create an eventbox and put the image inside it
  my $event_box = Gtk2::EventBox->new();
  my $image = Gtk2::Image->new();
  $vbox->pack_start($event_box, 1,1,0);
  $event_box->add($image);

# Load an image into a pixbuf. This gives more flexibility in
# manipulating the image than using an Gdk::Pixmap.
  my $pb = new_from_file Gtk2::Gdk::Pixbuf($filename);
        die "Failed loading test image!\n" unless $pb;

# create info label
  my $label = Gtk2::Label->new($filename);
  $vbox->pack_start($label, 0,0,0);

# Load the image into the image widget and resize it so that
# it fits the image
  $image->set_from_pixbuf($pb);
  $image->set_size_request($pb->get_width,
  $pb->get_height);

# Make event box accept motion events
  $event_box->set_events(["pointer-motion-mask"]);

# setup motion callback for the image widget
 $event_box->signal_connect(
   "motion-notify-event"=>\&cb_image_motion,[$label,$pb]);

 $mw->show_all();
}

create_widgets(@ARGV);

Gtk2->main();