Re: Event Handling

[James Muir <hemlock vtlink net>]

muppet wrote:

> James Muir said:
>  
>
> > Nice, but this handler will receive all events. Is there a way to
> > indicate to Gnome that my program is only interested in, say,
> > "button-press"  events and to call my handler
> > only for "button-press" events. Or do I have to handle all possible
> > events in my handler?
> >    
>
> Unfortunately, no.  GnomeCanvas does its own event routing, and
> GnomeCanvasItem gets a small subset of the events that GtkWidget gets.  You
> get to dispatch based on $event->type in your event handler.
>
> Something evil i have done in the past is create a table of these things:
>
>
>  %foo_event_dispatch = (
>      'button-press-event' => \&foo_button_press_event,
>      'button-release-event' => \&foo_button_release_event,
>  );
>  sub foo_event {
>     my ($item, $event) = @_;
>     my $handler = $foo_event_dispatch{$event->type};
>     return $handler
>          ? $foo_event_dispatch{$event->type}->($item, $event)
>          : FALSE;
>  }
>
> But depending on how much code you have in each one, that may be more work
> than it's worth.
>
>  
Thanks for the explanation.