[perl-Cairo] Add a subclassing example

[Torsten Schönfeld <tsch src gnome org>]

commit f1afe7d30222c348aafbc39467b0baf111eace85
Author: Torsten Schönfeld <kaffeetisch gmx de>
Date:   Mon May 10 23:54:01 2010 +0200

    Add a subclassing example
    
    Also, fix the file permissions of another example.

 examples/subclassing.pl |   54 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 54 insertions(+), 0 deletions(-)
---
diff --git a/examples/simple.pl b/examples/simple.pl
old mode 100755
new mode 100644
diff --git a/examples/subclassing.pl b/examples/subclassing.pl
new file mode 100644
index 0000000..10908a4
--- /dev/null
+++ b/examples/subclassing.pl
@@ -0,0 +1,54 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+my $surface = Cairo::ImageSurface->create ('argb32', 1000, 1000);
+my $context = CustomContext->create ($surface);
+$context->draw_star;
+$context->show_page;
+$surface->write_to_png ($0 . '.png');
+
+package CustomContext;
+
+use strict;
+use warnings;
+use Cairo;
+use Math::Trig qw/pi/;
+
+use base qw/Cairo::Context/;
+
+sub create {
+  my ($package, $surface) = @_;
+
+  my $self = $package->SUPER::create($surface);
+
+  return bless $self, $package;
+}
+
+sub draw_star {
+  my ($self) = @_;
+
+  my $width = $self->get_target()->get_width();
+  my $height = $self->get_target()->get_height();
+
+  $self->rectangle (0, 0, $width, $height);
+  $self->set_source_rgb (1, 1, 1);
+  $self->fill;
+
+  $self->save;
+  {
+    $self->set_source_rgba (0, 0, 0, 0.5);
+    $self->translate ($width / 2, $height / 2);
+
+    my $mx = $width / 3.0;
+    my $count = 100;
+    foreach (0 .. $count-1) {
+      $self->new_path;
+      $self->move_to (0, 0);
+      $self->rel_line_to (-$mx, 0);
+      $self->stroke;
+      $self->rotate ((pi() * 2) / $count);
+    }
+  }
+  $self->restore;
+}