Re: [Pan-users] Pan gmime-3 / Registering a callback function

[Rhialto]

On Sat 20 Apr 2019 at 16:22:56 +0200, Detlef Graef wrote:
> Hi,
> 
> I'm having a look at this issue:
> 
> https://gitlab.gnome.org/GNOME/pan/issues/77
> 
> I want to register a callback function for GMimeParserOptions:
> 
> https://developer.gnome.org/gmime/stable/gmime-GMimeParserOptions.html#g-mime-parser-options-set-warning-callback
> 
> with:
> 
> g_mime_parser_options_set_warning_callback ()
> 
> Is it ok to define a function something like this:
> 
> 
>   GMimeParserWarningFunc warning_cb (gint64 offset,
>                                      GMimeParserWarning errcode,
>                                      const gchar *item,
>                                      gpointer user_data)
>   {

I think the signature of warning_cb would be


  void                   warning_cb (gint64 offset,
                                     GMimeParserWarning errcode,
                                     const gchar *item,
                                     gpointer user_data)

because GMimeParserWarningFunc is the type of the function, not of the
return value of the function.

>     // do something with errcode
>   }
> 
> // -----------
> 
> https://developer.gnome.org/gmime/stable/gmime-GMimeParserOptions.html#GMimeParserWarningFunc
> 
> 
> How do I pass the callback function warning_cb correctly?
> 
>   gpointer user_data = NULL;
>   GMimeParserOptions *gmpo  = g_mime_parser_options_new();
>   g_mime_parser_options_set_warning_callback (gmpo, warning_cb, user_data);

That looks ok, going just by the docs as linked.
If you got a warning or error message from the compiler, it is probably
due to the wrong type of 'warning_cb'.

> Detlef
-Olaf.
-- 
___ Olaf 'Rhialto' Seibert  -- "What good is a Ring of Power
\X/ rhialto/at/falu.nl      -- if you're unable...to Speak." - Agent Elrond

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