wxruby users - Apr 2008 - wxRuby / wxWigets with C++

Hi,

I am experimenting with integration of C++ and Ruby. What exactly I would  
like to do is to provide an option to use Ruby and wxRuby for creation of  
GUI and doing algorithms in C++ and then displaying results in the openGL  
Canvas.

I can easily use openGl / Glut in "render" function in C++ say class  
VisualiseGraph, build using SWIG an extention to Ruby and then use this  
function (that does not take any parameters and returns void) to display  
on the wxGLCanvas
(
  @canvas.evt_paint { @canvas.paint { render } }
).

But I would also like to transfer the data from the form built using Ruby  
into some classes in C++. Like parameters: numbers and string. But I am  
wondering if it is possible to create controls in Ruby and then just  
assign then into C++ fields (the controls not values). For example

class FormInCpp
{
	wxTextField * someText;

	void setSomeText(wxTextField * param){
		someText = param;
	}

}

then use SWIG to build extention in module say Llap

and then

txt = Wx::TextCtrl.new(self, -1, "val")

form = Llap::FormInCpp.new
form.setSomeText(txt)

I thought these are in fact the same controls, they were written in C++,  
but I guess txt is not of type [wxTextField *], but rather
  #<SWIG::TYPE_p_wxTextCtrl:0xb7c49944>
  so how to get the pointer to wxTextField so I can manipulate the control  
 from cpp class like this

someText->GetValue()

and then do smthing with this value.

-- 
Kind regards,
Łukasz Łapiński

?ukasz ?api?ski wrote:
> I am experimenting with integration of C++ and Ruby. What exactly I would  
> like to do is to provide an option to use Ruby and wxRuby for creation of  
> GUI and doing algorithms in C++ and then displaying results in the openGL  
> Canvas.
>   
I wasn''t totally clear what you wanted - do you want to end up with a 
ruby script that calls some C++ extensions, or a compiled C programme 
that calls wxRuby to do a GUI. I think the latter will be
harder...
> But I would also like to transfer the data from the form built using Ruby  
> into some classes in C++. Like parameters: numbers and string. But I am  
> wondering if it is possible to create controls in Ruby and then just  
> assign then into C++ fields (the controls not values). 
Not quite sure how this would work. Unless the interface of your C++ 
library is very complex, it might be easier to do it the other way 
around, ie create a simple ruby wrapper around your C++ library (using 
SWIG or RICE) then use Ruby to transfer the values into the C library. 
Is there a particular reason this won''t work for
you?
> I thought these are in fact the same controls, they were written in C++,  
> but I guess txt is not of type [wxTextField *], but rather
>   #<SWIG::TYPE_p_wxTextCtrl:0xb7c49944>
>   so how to get the pointer to wxTextField so I can manipulate the control
>  from cpp class like this
>
> someText->GetValue()
SWIG provides a lot of useful functions for doing this, if you want. See 
http://www.swig.org/Doc1.3/Ruby.html#Ruby_nn50

in particular, SWIG_ConvertPtr which converts a VALUE to the underlying 
C++ object.

It''s generally used little directly, as it''s easier to use
%extend to
write methods in which the placeholder variable $self refers to the C++ 
object.

alex