On Mon, May 31, 2010 at 7:17 PM, Andreas Volz <[email protected]> wrote:
> Hello,
>
> I've a question about:
>
> EAPI void
> evas_object_smart_callback_add(Evas_Object *obj, const char *event,
> void (*func) (void *data, Evas_Object *obj, void *event_info), const
> void *data)
>
> Why is event_info a void* data type and not some type of struct? To
> which struct should I cast it to do something useful with it?
>
> There is:
>
> typedef struct _Evas_Event_Mouse_Down Evas_Event_Mouse_Down; /**< Event
> structure for #EVAS_CALLBACK_MOUSE_DOWN event callbacks */
> typedef struct _Evas_Event_Mouse_Up Evas_Event_Mouse_Up; /**< Event
> structure for #EVAS_CALLBACK_MOUSE_UP event callbacks */
> ...
>
> in Evas.h. But how do I know this by object_smart_callback_add? Normal I don't
> know it if I don't call evas_object_smart_callback_call() from my own code.
You don't, you need to know which function/event type you added to
know what type you get. In python, where we need to actually convert
to an object, we must do it. In C++, you can just leave it to the
user, or do as we do.
It is something like:
if type == EVAS_CALLBACK_MOUSE_DOWN, then
internal_cb = my_func_that_converts_to_mouse_down
internal_data = (this=this, cb=user_cb, data=user_data)
else ...
evas_object_event_callback_add(this->obj, type, internal_cb, internal_data)
void my_func_that_converts_to_mouse_down(void *data, Evas *e,
Evas_Object *o, void *event_info)
{
Evas_Event_Mouse_Down *ev = event_info;
internal_data = data;
internal_data->cb(internal_data->data, internal_data->this,
convert_to_cxx(ev));
}
boring, but it is C... so :-/
BR,
--
Gustavo Sverzut Barbieri
http://profusion.mobi embedded systems
--------------------------------------
MSN: [email protected]
Skype: gsbarbieri
Mobile: +55 (19) 9225-2202
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