Re: custom vfunc problem

[Kjell Ahlstedt <kjell ahlstedt bredband net>]

Haven't you mixed up signals and vfuncs? show and hide are signals. 
show_all, hide_all, map and allocate are vfuncs.

I'm not sure if the test for clutter_actor_real_allocate in 
clutter_actor_maybe_layout_children() can be problematic. It shouldn't 
be, when the vfunc is called. If it's not overridden by the user of 
cluttermm, the parent class version (i.e. the C code version) will be 
called, and the C code should find that klass->allocate == 
clutter_actor_real_allocate. But I see in the clutter code that 
clutter_actor_maybe_layout_children() is also called from 
clutter_actor_set_allocation(). Perhaps that call does not work as 
expected unless the CLUTTER_DELEGATE_LAYOUT flag is set.

Kjell

Den 2016-03-21 kl. 03:30, skrev Ian Martin:
> Hi,
> I'm slowly working my way through clutter trying to wrap it.  I've 
> come up against a recurring problem where the C functions work but the 
> wrapped functions don't; looking at the clutter source, I think the 
> problem might be that the vfuncs are listed in the class_init function 
> with a _real_ qualifier:
>  klass->show = clutter_actor_real_show;
>   klass->show_all = clutter_actor_show;
>   klass->hide = clutter_actor_real_hide;
>   klass->hide_all = clutter_actor_hide;
>   klass->map = clutter_actor_real_map;
>
> etc, and then in the source files this sort of thing happens:
>
>   if (CLUTTER_ACTOR_GET_CLASS (self)->allocate == 
> clutter_actor_real_allocate)
>     goto check_layout;
>
> which would mean that if every C++ instance is derived, it won't call 
> the base class function; if possible, I should be pointing the vfuncs 
> to the _real_ method, but as they're not declared in the headers this 
> won't work either.
>
> Is that correct?  Is there an example in another wrapped library of 
> this being done successfully?
>
> Ian.