Re: [Banshee-List] Hyena.Gui.Theatrics.Stage.ActorStep problem

["Aaron Bockover" <abockover novell com>]

You're saying that if a handler has already been registered on the
event, to throw an exception in the add/remove accessors? Or are you
saying that only one handler should be allowed to be registered on the
event?

--Aaron


On Sun, 2008-03-09 at 22:57 -0400, Scott Peterson wrote:
> The Hyena.Gui.Theatrics.Stage.OnActorStep() method returns the result
> of the ActorStep handler (if it is not null). There is a potential bug
> here if more than one ActorStepHandlers are registered with the Stage:
> only the last handler to be registered will effect the outcome of
> OnActorStep(). This is unlikely, but possible, and if it were to
> happen to some poor dev, I bet they'd have a hell of a time figuring
> out what's wrong. Some possible solutions:
> * Change the ActorStep event to an ActorStepHandler property. This
> will make it perfectly clear that only one handler should be
> registered.
> * Require the passing of an ActorStepHandler in the Stage constructor.
> This has the same effect as the above.
> * Add custom add/remove blocks to the ActorStep event. If a handler
> has already been registered, throw an exception. Any error-prone code
> should encounter this exception as soon as it tries to run.
> * Add custom add/remove blocks to the ActorStep event to keep the
> registered handlers in a Collection. In OnActorStep, iterate through
> the collection and &= the results from each handler. This could also
> lead to potentially confusing behavior, but it makes more sense than
> the current system.
> 
> As I see it, the choice is really over what syntax we prefer. If we
> want to go with the event syntax, I think the custom add/remove blocks
> and exception is the way to go. The downside is that people don't
> expect to get an exception just by registering an event handler. So it
> seems to me that a property is the best solution. Other opinions?
>