Re: Where do I get my Cairo context from (in GTK3)?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On 25/04/2016 12:03, hreba wrote:
> On 04/25/2016 09:40 AM, Dmitry A. Kazakov wrote:
>
>> If you instantiate it with GObject, why using Gtk_Widget instead?
>
> I use Glade and Gtk_Builder.Get_Object returns GObject. Nearly all
> examples for handler connection use Gtk_Widget so I did the same.

But it is still GObject_Record.

>> I suppose sn_draw is "draw".
>>
> Correct.

Is it Signal_Name in Connect? Recent GtkAda changes broke a lot of 
things. Try a plain string literal instead.

>>> So where do I get the cairo context from?
>>
>> As you did. Just make sure that all parameters of Connect match. Instead
>> of pointer conversion use object conversion. E.g.
>>
>>     Gtk_Widget_Record'Class (Obj.all)'Unchecked_Access
>
> So I changed my call of Connect to
>
>        DA_Ret_Callback.Connect
>     (Gtk.Widget.Gtk_Widget_Record'Class(obj.all)'Unchecked_Access,
>      sn_draw,
>      DA_Ret_Callback.To_Marshaller(Draw_Handler'Access),
>      hd);
>
> but I still get the same error message from the compiler.

Try to specify a concrete marshaller in conversion, to narrow the 
problem. To_Marshaler is a renaming. Use the original full name from the 
marshaler package that instantiates the Draw's profile. You have a type 
mismatch in some of the parameters.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de