#!/usr/bin/perl
package scaleme;

use strict;
use diagnostics;
use warnings;

use Gtk2 '-init';
use Glib qw(TRUE FALSE);

# Display this image
my $path = 'change_this_directory/cat.bmp';

# Open a Gtk2 window with a Gtk2::TextView 
my $window = Gtk2::Window->new('toplevel');
$window->set_title('scaleme');
$window->set_position('center');
$window->set_default_size(800, 600);
$window->signal_connect('delete-event' => sub {

    Gtk2->main_quit();
    exit;
});
            
my $frame = Gtk2::Frame->new();
$window->add($frame);

my $scrollWin = Gtk2::ScrolledWindow->new(undef, undef);
$frame->add($scrollWin);
$scrollWin->set_policy('automatic', 'automatic');     
$scrollWin->set_border_width(0);

my $textView = Gtk2::TextView->new;
$scrollWin->add_with_viewport($textView);

if (-e $path) {

    # Display a photo of a cat face
    my $pixbuf = Gtk2::Gdk::Pixbuf->new_from_file($path);

    my $buffer = $textView->get_buffer();
    $buffer->insert_pixbuf(
        $buffer->get_end_iter(),
        $pixbuf,
    );

    # Make the overall image 20% bigger, but the cat's face is its 
    #   original size (and centred in the middle)
    my $factor = 0.2;   
    my $w = $pixbuf->get_width();
    my $h = $pixbuf->get_height();

    my $pixbuf2 = Gtk2::Gdk::Pixbuf->new(
        'GDK_COLORSPACE_RGB',
        FALSE,
        $pixbuf->get_bits_per_sample(),
        ($w * (1 + $factor)),
        ($h * (1 + $factor)),
    );

    $pixbuf->scale(
        # $dest
        $pixbuf2,
        # $destx, $desty
        0,
        0,
        # $dest_width, $dest_height
        ($w * (1 + $factor)),
        ($h * (1 + $factor)),
        # $offset_x, $offset_y
        ($w * ($factor / 2)),
        ($h * ($factor / 2)),
        # $scale_x, $scale_y
        1,
        1,
        # $interp_type
        'GDK_INTERP_NEAREST',
     );

    $buffer->insert_pixbuf(
        $buffer->get_end_iter(),
        $pixbuf2,
    );
}

$window->show_all();   
Gtk2->main();