Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!spool.mu.edu!munnari.oz.au!uniwa!fennel.cc.uwa.oz.au!a_dent
From: a_dent@fennel.cc.uwa.oz.au
Newsgroups: comp.sys.mac.programmer
Subject: Re: Novice Think C Class Questions
Message-ID: <1991Mar16.122957.3082@fennel.cc.uwa.oz.au>
Date: 16 Mar 91 04:29:57 GMT
References: <3895.27D0636D@stjhmc.fidonet.org> <15953@hoptoad.uucp>
Organization: University of Western Australia
Lines: 73

Kevin Brewer writes in a message to All
KB> 1) I have an appliction that should have three or four windows. 
KB> My (mis?)understanding of the Document Class is that the Doc 
KB> Class should  control the windows, yet you can only have one 
KB> window associated with  each doc instance. How do you create 
KB> more than one window - say a drawing pane and a text edit pane 
KB> - for each doc? Obviously, I'm  confused. I would appreciate 
KB> any direction on this.

I implemented a program which allows multiple windows (a magazine layout
program - a page per window) and so had to be able to change the main
pane - sounds like what you're doing.

I wrote a subclass of CWindow, as shown below, and added a method to the
normal (overridden, from the sample application) Document class:

procedure CREIWAPrintDoc.changeMainPane (newMain: CREIWAPrintPane; 
   newWindow: CWindow);
 begin
  itsMainPane := newMain;
  itsGopher := newMain;
  gGopher := newMain;
  itsWindow := newWindow;
 end;

---------------------------------------------------------------------------

 procedure CREIWAPrintWindow.makeMyPaneMain;
  var
   thePane: CREIWAPrintPane;
   itsScrollPane: CScrollPane;

  function isREIWAPane (theObject: CObject): boolean;
  begin
   isREIWAPane := member(theObject, CREIWAPrintPane);
  end;  { isREIWAPAne}

 begin  { makeMyPaneMain }
  CObject(itsScrollPane) := itsSubviews.FirstItem;
  CObject(thePane) := itsScrollPane.itsSubviews.FirstSuccess(isREIWAPane);
  CREIWAPrintDoc(itsSupervisor).changeMainPane(thePane, SELF);
 end;  { makeMyPaneMain }


 procedure CREIWAPrintWindow.select;
 begin  { select }
  SELF.makeMyPaneMain;
  inherited select;
 end;  { select }

 procedure CREIWAPrintWindow.Activate;
 begin  { Activate }
  SELF.makeMyPaneMain;
  inherited Activate;
 end;  { Activate }

--------------------------------------------------------------------------------
The following fragment of code goes in the Document's DoCommand method and
lets you have a menu of all the windows:

  if (theCommand < 1) & (hiWord(thecommand) = -(PageMenuID + 1)) then begin   
{ selection from Page menu }
    thePageIndex := -loWord(theCommand);  { note the sign change!! }
    CObject(theWindow) := itsWindowList.NthItem(thePageIndex);
    theWindow.Select;
   end;

Hope this helps.

Andy Dent                     A.D. Software phone 09 249 2719
Mac & VAX programmer          94 Bermuda Dve, Ballajura
a_dent@fennel.cc.uwa.oz       Western Australia  6066     
a_dent@fennel.cc.uwa.oz.AU (international)