Re: Drawing on a DrawingArea without using polymorphism

["Jonathon Jongsma" <jonathon jongsma gmail com>]

On 9/18/06, Atma <fcamblor gmail com> wrote:
> Hi there !
>
> I'd like to draw a line on a drawing area.
> I succeeded by creating a subclass of DrawingArea and overriding the
> on_expose_event() method... but I no longer want to use this behaviour.
> So I used signals in order to delegate this task :
>
> <code>
> Gtk::DrawingArea* mainDrawingArea;
> // Initializing my drawing area...
> mainDrawingArea->signal_expose_event().connect(sigc::ptr_fun(&
> SignalsLinker::drawMainArea));
> </code>
>
> Then, implementing drawMainArea() :
> <code>
> bool SignalsLinker::drawMainArea(GdkEventExpose *event){
>          printf("Draw !\n");
> }
> </code>
>
> The "draw" is successfully displayed !
> Now, what I'd want to know, is the way of retrieving my concerned
> DrawingArea in order to gather the corresponding Window object and draw
> lines on it .. is it possible ?
> (note : I won't have any pointer on my DrawingArea in my SignalsLinker class
> ... wouldn't it be possible to retrieve it with the GdkEventExpose object
> given ?)
>
> Thanks in advance ;)

You could always use sigc::bind to pass a pointer to the DrawingArea
along as a parameter to your drawMainArea() handler.

--
jonner