Re: Making a subclass help

[muppet <scott asofyet org>]

On Saturday, June 12, 2004, at 09:55 AM, Grahame White wrote:

> sub clickcell{
>     my $clicked = @_;

welcome to the wild & wonderful world of scalar versus array context.  
when you take an array in scalar context, you get the number of 
elements in the array.  here, the number of elements in @_ is 1, so 
you're getting 1 in $clicked.

you want to say either

      my $clicked = shift;

or

      my ($clicked) = @_;

or even

      my $clicked = $_[0];

here, and it works fine.

>     print $clicked . "\n";
>     print $cells[$clicked]->get_image . "\n";
>     $cells[$clicked]->set_image(image => "ball.png");
>     return 0;
> }


> What _is_ happening, however, is that when I click a cell instead of 
> passing the clicked IButton's index to clickcell() it's passing 1 
> instead.  What's puzzling me in particular is that before adding the 
> image property the correct IButton index was being passed to the 
> function.

i changed it to use get('index') instead of get_index(), but the 
problem was the same.  you probably changed something else in there 
somewhere.


> What I'm eventually going to make is a simple peg-solitaire game. It's 
> just a test program that I start off making each time I try a 
> different language. It's got simple rules, flexes the mind muscles a 
> bit, gives a common example to compare against and also produces an 
> 'artifact' that I can say "woo look what I built" about :)

nifty.  a hint: it will run rather a bit faster if you don't load a 
file every time a button is clicked (you probably knew that already).  
GdkPixbufs will help, but if create server-side GdkPixmaps for the 
image icons, you'll save a lot of network traffic (i run x remotely, 
where it's noticeable).

   # on startup, preload the icons
   foreach my $name (qw(blank ball)) {
        my $pixbuf = Gtk2::Gdk::Pixbuf->new_from_file ("$name.png");
        my ($pixmap, $mask) = $pixbuf->render_pixmap_and_mask (65535/2);
        $icons{$name}{pixmap} = $pixmap;
        $icons{$name}{mask} = $mask;
   }
   ...
   sub Mup::IButton::set_image {
        my ($self, $icon) = @_;
        $self->child->set_from_pixmap ($icon->{pixmap}, $icon->{mask});
   }
   ...
   $cell->set_image ($icons{'ball'});


in fact, you could just make the button class know about the icons (and 
keep the list of pixmaps), and tell the button which icon you want it 
to display, by name.


--
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