[wxVTK] Resizing problem under wxMSW

[John N. <jn...@mc...>]

Hi,

I ran into a highly frustrating problem when using 
wxVTKRenderWindowInteractor as a child window in wxMSW.  Specifically, I 
  have a wxFrame with a few wxSashLayoutWindows, and I'm using the wxVTK 
window as the "filler" window in wxLayoutAlgorithm::LayoutFrame().

When the frame first poped up, everything would look fine.  But when I 
resized the window or dragged a sash, the wxVTKRenderWindowInteractor 
would mysteriously get too big for its alloted space.

After much investigation I discovered that when its ParentId is not set, 
vtkWin32OpenGLRenderWindow automatically increases its size to make room 
for the title bar and window borders.  In my case at least, this is 
undesirable behavior.

The solution is for wxVTKRenderWindowInteractor to set its render 
window's ParentId as well as its WindowId.  In 
wxVTKRenderWindowInteractor::OnPaint(), I changed

   if(!Handle)
   {
     Handle = GetHandle();
     RenderWindow->SetWindowId(reinterpret_cast<void *>(Handle));
   }

to

   if(!Handle)
   {
     Handle = GetHandle();
     RenderWindow->SetWindowId(reinterpret_cast<void *>(Handle));
#ifdef __WXMSW__
     RenderWindow->SetParentId(reinterpret_cast<void 
*>(this->GetParent()->GetHWND()));
#endif //__WXMSW__
   }

I made the call to SetParentId() wxMSW-specific, since wxGTK et al seem 
to work just fine, and I didn't want to break them.

Thanks,
John
-- 
John Norris
Research Programmer
Center for Simulation of Advanced Rockets
http://www.uiuc.edu/ph/www/jnorris