On Mon, Nov 22, 2010 at 5:19 PM, Mike Wyatt <[email protected]> wrote:
> > > Fair warning - Redesign opportunity:
> > > Seems that the event propagation code was amidst a change for the
> > > 0.3.0 release, and then not ever completed.
> > > By example, Scenes and Layer supposedly inherits code from
> > > scene.EventHandlerMixin, but that code is never executed, and anyway
> > > in that code the line
> > > scene = self.get(Scene)
> > > will traceback any time. ( probably wanted to be scene =
> > > self.get_ancestor(Scene) )
>
> I see. Is properly implementing EventHandlerMixin as simple as fixing
> the above line and then calling EventHandlerMixin.add() and .remove()
> from the Scene, like this?
>
> +class Scene(cocosnode.CocosNode, EventHandlerMixin):
> + def add(self, child, z=0, name=None ):
> + super(Scene, self).add( child, z, name )
> +
> + def remove(self, obj):
> + super(Scene, self).remove( obj )
>
>
If we want to use mixin style, we begin by
change the base classes order in Scene (that made the mixin's add
be called, and the super in the mixin takes care to call CocosNode.add)
replace
scene = self.get(Scene)
with
scene = self.get_ancestor(Scene)
that eliminates a traceback, and looks as plausible (but needs to be
reexamined later to see what behavior will produce)
To activate the mixin in Layer, we should similarly invert the base
classes
order, but here some other analysis and changes are needed:
a) the mixin code duplicates code in Layer's on_enter on_exit, should we
eliminate the later ?. probably yes
b) how we handle a remove - add a layer to a running scene ? ( empty
and reconstruct the stack probably)
c) there is similar code in Layer and Scene (remove_all_handlers,
push_all_handlers). Should we move some to the mixin ?
By the way, reconstructing the stack in the add to respect front to back
can
be done calling remove_all_handler / push_all_handlers in the mixin, at the
scene level, (if the scene was running)
Will see to make a branch exploring this way.
But I can be better to use a component approach instead of a mixin one.
That way if a certain game don't fits well with the 'event propagation is
front to back' it can make it own custom component and give it to the
scene and layer.
I will think about that.
--
claudio
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