Re: Getting view in the document class

From:

Eric Lilja <mindcoolerremoveme@gmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 28 Jun 2007 01:46:25 +0200

Message-ID:

<eAXyfVRuHHA.1164@TK2MSFTNGP02.phx.gbl>

David Wilkinson wrote:

Eric Lilja wrote:

I'm writing a simpliefied "Game of Life" to teach myself MFC and get
experience in using MSVC++ 8.0. Anyway, it's SDI/DocView-type program.
The document class creates a tile matrix that represents the game
board. Each tile must know about the view where it's located. I'm
doing this in my OnNewDocument:

BOOL
LifeDocument::OnNewDocument()
{
   VERIFY(CDocument::OnNewDocument());

   static POSITION pos = GetFirstViewPosition();
   /* GetNextView() take a non-const reference to a POSITION so we
can't use nested calls... */
   static MyView *view = dynamic_cast<MyView *>(GetNextView(pos));

   ASSERT(view);

   tile_matrix_ = new TileMatrix(view, num_rows, num_cols);

   return TRUE;
}

My question is simply: Is this the proper way to obtain a pointer to
view from inside the document class? As I said above, this is an SDI
application so there will always be only one view at any given time.

Eric:

The document should not know about the views. When the document changes
it should call UpdateAllViews(), and each view should update itself from
the document.

Why do you have multiple views anyway?

Ah, well, every tile on the game board share the same view so I have
only one. The problem is that one of the data members of document class
needs the view when it's constructed. I sense a design problem here but
I have no better idea on how to solve it.