Re: regarding definition of _PangoCairoFont

[John Ralls <jralls ceridwen fremont ca us>]

On Sep 6, 2012, at 7:20 AM, Parth Kanungo <kanungoparth gmail com> wrote:

> Hello all,
>  
> There is a statement in pangocairo.h 
>  
>  typdef struct _PangoCairoFont PangoCairoFont;
>  
> I am using visual studio and when I right click on "_PangoCairoFont" and click "Go to definition", it does not take me anywhere.
>  
> I remember there are some other similar data-strucutures which do not appear to have a definition.
> Are they defined in some library, which I am missing in my visual studio solution file.
>  
> Any help/suggestion would be appreciated.
> 
> Thanks a ton.

That's part of the pattern for declaring and defining classes using GObject. You can find documentation of how GObject classes are built at http://developer.gnome.org/gobject/stable/.

The usual pattern in GObject based-libraries is that if the class is to be opaque -- meaning that the member variables are private -- that the header file will contain only the typedef and the struct will be either in the implementation file or in a private header file which is not exported to the public include directory. The latter is the case here: The struct definitions are in pangocairo-private.h.

Regards,
John Ralls