On 11/01/2011, at 5:35 PM, Jerry Krinock wrote: > But that assumes that the data was sorted with some old descriptors to begin > with. It seems like this would not work if the objects had been manually > arranged into some arbitrary order by the user.
True, but then you'd make the reordering step undoable (i.e. moveObject:toIndex: or similar registers with undo). To make Undo really work for you, you have to make everything undoable, then all state changes in your data model are tracked and any given undo operates on a data state that is consistent with its own internal picture of the data. I suppose if all else fails you could simply make Undo take a snapshot of the data itself but that strikes me as potentially very inefficient. --Graham _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
