document/view STL and modern C++ Topic is solved

[sergio]

Hi,

does someone knows if there is a problem/bug when combining the doc/view architecture and the STL? I did the classical "doodles" example using openGL instead of the traditional device context approach:

Code: Select all

/******************************************************************************/
void Canvas::OnPaint(wxPaintEvent& event)
{
     wxPaintDC dc(this);   
     SetCurrent();
     glClear(GL_COLOR_BUFFER_BIT);
     glPushMatrix();
     if(m_View)
          m_View->OnDraw(&dc);
     glPopMatrix();
     SwapBuffers();
}
/******************************************************************************/

Code: Select all

/******************************************************************************/
void GraphicsView::OnDraw(wxDC *dc)
{
     GraphicsDoc *doc=(GraphicsDoc *)GetDocument();
     std::list<Shape *>::const_iterator pos; 
     for(pos=doc->m_Shapes.begin();pos!=doc->m_Shapes.end();++pos) //code crashes somewhere around here
          (*pos)->Draw(); 
}
/******************************************************************************/

I had so strange problems (if I changed the container to a vector then everything was fine for example) that I decided to go back to the primitive "frame" architecture I'm used to:

Code: Select all

/******************************************************************************/
void Canvas::OnPaint(wxPaintEvent& event)
{
     wxPaintDC dc(this);   
     SetCurrent();
     glClear(GL_COLOR_BUFFER_BIT);
     glPushMatrix();
     std::list<Shape *>::const_iterator pos;
     for(pos=m_Shapes.begin();pos!=m_Shapes.end();++pos)
          (*pos)->Draw();   
     glPopMatrix();
     SwapBuffers();
}
/******************************************************************************/

the only real difference here is that I call paint for the whole list FROM the Canvas (since m_Shapes is now a member of Canvas and not of GraphicsDoc as before) but now it works perfect. What am I doing wrong?
Thanks,

Sergio

P.D: why doesn't dynamic_cast work properly and instead the unsafer C downcasting system works fine? I mean:

Code: Select all

/******************************************************************************/
Canvas::Canvas(wxWindow *parent, wxWindowID id,const wxPoint& pos, const wxSize& size)
    : wxGLCanvas(parent, (wxGLCanvas*) NULL, id, pos, size)
    
{    
     m_Frame = (GraphicsFrame *)parent; //dynamic_cast<GraphicsFrame> *(parent) makes this crash!!!
     SetCurrent();
     glClearColor(0.5,0.5,0.5,0.0);
     glOrtho(-10.0,10.0,-10.0,10.0,-10.0,10.0);
}    
/******************************************************************************/

[daddydave]

Code: Select all

     m_Frame = (GraphicsFrame *)parent; //dynamic_cast<GraphicsFrame> *(parent) makes this crash!!!

Just a guess, but shouldn't that be

Code: Select all

dynamic_cast<GraphicsFrame*>(parent) 

instead of

Code: Select all

dynamic_cast<GraphicsFrame> *(parent) 

?

[sergio]

Yup, you're right. Just a mistake when typing the message though but the tested code was written correctly. Thanks anyway. Anyone please?

[phlox81]

maybe the parent isn't a frame?
Have you tried static_cast<YourFrame*> ?

[sergio]

Anyone? I find it sooo strange that I have to use C casting instead of modern C++ techniques....

[sergio]

Jorg told me why, if anyone is interested:

http://wiki.wxwidgets.org/docbrowse.cgi ... rview.html

Regards,

Sergio