Hi Mattia,
Thank you for this solution. It works. However, I just found a bug in another
program I made that was caused by re-blessing an object and I am afraid that
this re-blessing might cause problems in the future and I might need to
redesign the app.
It would be very helpful if you could change the constructors, because it is
the same with Wx::Frame, Wx::SimpleApp and others and it is counterintuitive to
do
use Wx;
my $app = Wx::SimpleApp->new;
It would be much better if we could do:
use Wx::SimpleApp;
my $app = Wx::SimpleApp->new;
This way it would be easier to subclass.
Ideally, it would be better to be able to use the constructor of Wx, like:
use Wx;
my $app = Wx->new;
Octavian
----- Original Message -----
From: "Mattia Barbon" <mattia.bar...@libero.it>
To: "Octavian Rasnita" <orasn...@gmail.com>
Cc: <wxperl-users@perl.org>
Sent: Saturday, August 07, 2010 11:47 PM
Subject: Re: Subclassing an empty class?
> Octavian Rasnita wrote:
>
> Hi,
>
>> Is it possible to subclass some empty classes like Wx::TextAttr?
>
> Some classes are tricky to subclass, but not because they are empty.
>
>> I have also tried to use Wx:
>>
>> package Style;
>> use Wx;
>> use base 'Wx::TextAttr';
>>
>> In this case it doesn't tell that Wx::TextAttr is empty, but if I add a
>> certain method in this package, that method can't be used because it gives
>> the error telling that there is no such a method defined in Wx::TextAttr.
>
> I'm not sure if this is easy to fix in wxPerl without requiring a
> change to all constructors. I'll think about it. In the meantime you
> can just rebless the object:
>
> package Style;
> use Wx;
> use base 'Wx::TextAttr';
>
> sub new {
> my $class = shift;
> my $self = $class->SUPER::new( @_ );
> bless $self, $class;
>
> return $self;
> }
>
> 1;
>
> Note: I haven't tested it, but it should work. One problem with this
> approach is that, since the text attr is used as a value in wxWidgets,
> there is no way to preserve identity, so if you do:
>
> $text->SetStyle( 0, 100, $myclass );
> my( $ok, $style ) = $text->GetStyle( 0, 100 );
>
> the returned $style object will be a copy of your object, and there is
> no way to automatically bless it to the correct class.
>
> HTH,
> Mattia
