Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!sun-barr!newstop!sun!plx!johnc
From: johnc@plx.UUCP (John C.)
Newsgroups: comp.windows.ms
Subject: Re: How does Excel do cells
Summary: Probably only the current cell is a window
Keywords: Excel cell window spreadsheet
Message-ID: <2121@plx.UUCP>
Date: 7 Dec 89 22:27:36 GMT
References: <49529@ccicpg.UUCP> <106580073@hpcvlx.cv.hp.com>
Reply-To: johnc@plx.UUCP (John Ciccarelli)
Followup-To: comp.windows.ms
Organization: Plexus Software, Santa Clara, CA
Lines: 17
Sender:

I'll bet Excel uses DrawText to write the cell contents, and uses
just *one* additional window for the current cell (the only place
data entry is allowed).  The current-cell window is probably
MoveWindow'd around the spreadsheet window as you change the
current cell position with the mouse or arrow keys.  The key 
concept here is that even *controls* (child windows) can be 
MoveWindow'd, not only app windows or their popups.

It should be easy to test this theory -- just bring up the Spy app
which is part of the SDK.  Choose "Window / Set", then move the cursor 
around the Excel display and see if the window info displayed in Spy's
dialog changes as you do so.  You might even be able to see the
WM_MOVE being sent to the current-cell window, if my guess pans out.

If anyone tries this, please e-mail me your findings...

/John Ciccarelli (johnc@plx.uucp --or-- ...sun!plx!johnc)