Re: custom_widget example not working

[Immanuel Scheerer <scheerei in tum de>]

>>More precisely I want to create a SDL widget. So i have to draw it
>>myself.
>>
>>Thanks for your answer, Murray.
>
>
> I asked about creating a gtkmmsdl widget not so long ago, so I thought I
> would post you my attempt. Its available at
> http://www.bath.ac.uk/~ma2snm/gtksdl_example/ and it does what I want it
> to do. The widget should be fairly easy to use, and also works on
> windows. You have to create a timeout signal to draw to the surface
> every so often, as otherwise the sdl surface gets drawn over by gtk (how
>  I understand it anyway). Something like this is fine,
>
> Glib::signal_timeout().connect(sigc::mem_fun(*this,
> &MainWindow::renderView),100 );
>

Your SDL-widget is derived from Gtk::DrawingArea and not from Gtk::Widget. That 
means that all function calls (except the one to the overriden on_expose_event) 
 are handed on to the underlying GtkDrawingArea. That's why the SDL competes 
against the GtkDrawingArea. This is also a performance issue.

It would be desirable to not have an underlying GtkWidget which draws itself.