muppet <[EMAIL PROTECTED]> writes:
>
> Furthermore, you want to compare
> the boxed objects by value, not by address, because the C code is
> allowed to and often does copy boxed objects at will.
Oh, umm, yep copies or aliases to the underlying C pointer will be ok.
Unless $self+0 (the ref numerically) moves about, that'd be no good.
> I'm curious as to what you're trying to do; with more info we could
> give better alternative suggestions.
:) I was thinking about representing a colour allocated in a colormap
as a subclass of Gtk2::Gdk::Color, along the lines below (incomplete).
The advantage would be automatic freeing of the pixel on chucking away
the object, plus some room for a friendly widget-oriented "new" func.
The actual pixel resource is of course just an integer, but if it's in a
subclass of Gtk2::Gdk::Color then you can pass it straight to the GC
colour setting funcs and stuff. The extra instance data is the
Gtk2::Gdk::Colormap object for use in the eventual freeing.
(I'm normally against excessive OOP, I'm slightly suspicious this idea
might be a case of that. Within a widget there's probably enough good
places to alloc/free/change that you don't need an object wrapper to
manage the lifespan, if you know what I mean. And getting it wrong has
no effect on a TrueColor visual of course, though a way to be confident
that you'll be doing the right thing on a rarely used pseudocolor might
be no bad thing.)
package Gtk2::Ex::ColorAlloc;
use strict;
use warnings;
use Carp;
use Gtk2;
use base 'Gtk2::Gdk::Color';
our %color_to_colormap = ();
sub new {
my ($class, %params) = @_;
# ... various friendly option crunching
my $color = Gtk2::Gdk::Color->parse ($name)
or croak "Gtk2::Ex::ColorAlloc->new: cannot parse colour \"$name\"";
$colormap->alloc_color ($color, $writeable, $best_match)
or croak "Gtk2::Ex::ColorAlloc->new: cannot allocate colour cell";
my $self = bless $color, $class; # rebless
my $key = $self + 0; # hash by address
$color_to_colormap{$key} = $colormap;
return $self;
}
sub DESTROY {
my ($self) = @_;
my $key = $self + 0; # hash by address
if (my $colormap = delete $color_to_colormap{$key}) {
$colormap->free_colors ($self);
}
$self->SUPER::DESTROY;
}
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