| Subject: | passThrough can() support |
| Date: | Mon, 11 Jul 2011 09:04:42 +1000 |
| To: | bug-GD-Window [...] rt.cpan.org |
| From: | Kevin Ryde <user42 [...] zip.com.au> |
In passThrough mode it'd be good if can() on the GD::Window reflected
the methods that are available from the underlying GD.
For example foo.pl says
can(png) no
Call ->png
ok, length 83
where I hoped can('png') might be true (coderef for GD::Window object),
since a $window->png() call will work.
In GD I believe the availability of the png() and jpeg() methods depends
on whether it's built with the respective libpng and libjpeg, so it can
make sense to check for them with can().
I think a custom can() is usual when making an AUTOLOAD for methods.
When I've done it I've shared a "create-the-method" func for the two.
The autoload creates and calls (or dies if no such method), the can()
creates and returns the coderef (or return undef if no such underlying
method, or no passThrough option).
#!/usr/bin/perl -w
use strict;
use GD;
use GD::Window;
my $im = GD::Image->new(5, 5);
$im->colorAllocate(0,0,0);
my $win = GD::Window->new($im,
0,0, 4,4,
0,0, 4,4,
passThrough => 1);
my $coderef = $win->can('png');
if ($coderef) {
print "can(png) yes\n";
} else {
print "can(png) no\n";
}
print "Call ->png\n";
$win->png;
my $str = $win->png;
print " ok, length ",length($str),"\n";