[Macdoku-developers] Update

[bob <kr...@ma...>]

Here is where I am at with respect to the current development.

Initially, I added an UndoManager which is still there and added  
storing the current Cell in Command.  As
I got further into it and in studying NSUndoManger, I removed the  
Cell storage and went back to a system
similar to Andreas's original code.  However, I added kind of a  
simulation of NSInvocation.  Now, when a
move of any kind is pushed onto the undo stack, it can contain  
multiple parts.  For instance, entering a
guess in a cell, pushes the old/new guess onto the undo stack and it  
also pushes every possible that
was eliminated by that move.  So, a redo will simply reverse the  
operation in its entirety.

Also, I moved the code out of CustomCanvas that had anything to do  
with undo and moved all that code
to either Grid or UndoManager with UndoManager taking the brunt of  
it.  This greatly simplifies CustomCanvas
when it comes to game play and does what I have been reading about in  
moving the game code into the
model object, Grid, per the Model-View-Controller theme.

If possibles are not being shown/tracked, then I am skipping over a  
lot of logic which does setting/checking
using them.  If a player decides to display the possibles, then I  
will simply recalculate them as was done
in the past.  For now though, all possibles only have to be  
recalculated once at the beginning of a game
or if a player chooses to display the possibles.

I am about 60-70 percent done and am hopeful that I can complete it  
in the next week.  I have not tested
anything because I am still tearing things apart and rebuilding them  
(now mostly in Grid), but I do have
the code compiling cleanly again.

Also, the redo stack should work as well similar to how NSUndoManager  
works.  It is too bad that
NSUndoManager does not support the NSCoding protocol, because then I  
could have just used it.

Anyway, I am pounding away at the code. ;)

Bob