On Oct 31, 2008, at 1:19 AM, Ashley Clark wrote:
> I'm pretty sure I've seen someone ask this before but I just can't
> find it in Google. So I'll ask again.
>
> I have undo/redo working throughout my program but I seem to
> remember earlier that upon opening a document and immediately after
> beginning to change the state of a text field that the document
> dirty status would be changed, before an actual undo was registered
> on the undo stack. (As a result of -objectDidBeginEditing:?)
>
> Somehow I've disabled this behavior and for the life of me I can't
> determine what I've done wrong or how to get that behavior back.
>
> Does anyone have any clues?
After a lot of stepping through the debugger I've seen that in new
NSDocument based projects that edits happening through a controller
send an -objectDidBeginEditing: to the NSDocument object via
[NSValueBinder _startChanging].
In my project though, for some reason I have yet to uncover,
NSValueBinder's _startChanging method checks to see if my
NSWindowController subclass responds to objectDidBeginEditing: when
that returns NO it stops looking and never checks my document
subclass. If I implement objectDidBeginEditing and
objectDidEndEditing: and have them forward those messages on to my
document the document dirty state is represented correctly as it is in
a new project.
So, this suggests that somehow I've mucked up the responder chain
between my window controller and my document but I don't see anywhere
where I might have done something like that. To be honest though, I'm
not sure that I'd know how to without reading up a lot more on the
responder chain anyway. Before I read up on the responder chain to see
what I might have done, does anyone know if I'm on the right track here?
Ashley
