Ephemeral Changes

FROM : Gerriet M. Denkmann
DATE : Tue Mar 25 18:48:49 2008

I have a document based Cocoa editor, which handles simple text files 
(setRichText: NO).
It handles undo and font changes.

But the files are just plain text files; no font information gets 
stored.

So I would like that the document does NOT get dirty 
(isDocumentEdited) if only the font has been changed.

This would imply that we have two kinds of changes: "real" changes 
(like typing, cut and paste of text, etc.) and "ephemeral" changes 
(e.g. change of font).
Both are recorded by the NSUndoManager, but only "real" changes make 
the document dirty.

How could this be done in 10.4.11 ?

Kind regards,

Gerriet.