Re: Widget class loading (was: Re: relase plan, 1st draft)

[goran kirra net]

On Tue, Nov 12, 2002 at 01:26:56PM +0100, Joern Reder wrote:
> What about such a solution: each widget class is derived from 
> Gtk2::Loader (probably a bad name, but Ok for this mail ;)

There is a base global class: "Gtk2::_Object"

> It has a 'new' subroutine (and probably other different named 
> constructor subroutines) like this:
>
>   sub new {
>     my $class = shift;
>     require $class; # or: eval "use $class"; die $@ if $@;
>     $class->new(@_);
>   }
>
> Gtk2.pm sets the @ISA array of all widget classes to qw(Gtk2::Loader) 
> and loads Gtk2::Loader. So when constructing a widget object, 
> Gtk2::Loader's constructor is accessed first, which loads the real code
> and then executes the widget's constructor. Subsequent calls will find 
> the widget's constructor first, and everything should work with good 
> performance and as expected.
>
> Just a quick born idea, maybe it doesn't work, because I missed 
> something essential (also I don't know much about Gtk2's internals). 
> Just tell me ;)

How do you know what @ISA contains before the module is loaded?

> BTW: how did the Gtk module solved this problem?

There is a lazyloader mechanism in the old Gnome-Perl,
but AFAIK all code in lazy-loaded module must be compiled code in the main .so
(I could be wrong, just had a quick glance)
We want to use perl as far as possible.

/göran