Well, I was hoping maybe someone could show me the obvious that I was missing. :-) I guess I'm going to have to brush up on my undo handling, especially since I'm also doing some programmatic edits.
I didn't use the popover for now, just did separate undo/redo buttons, which works. But I would like to disable them if there is nothing in the respective undo/redo stacks. Yup, I could always poll it for canUndo/canRedo. Yeeech! That is in fact what I did for my 2-column font picker. They provided the means to have dependent columns in the PickerView, but no way to actually update them -- so I polled it. Works ok for something sparsely used, but I hate to use polling for something in long-term operation, like text editing. I guess the advantage of a single undo button/popover is that is is more like a Mac menu, although more persistent, allowing serial taps. It could also allow for undo/redo titles, although I notice that Pages didn't bother with such. The docs are still pretty sparse. I didn't even realize that UITextView supported undo/redo until I accidentally (who knows how) triggered an alert asking if I wanted to undo typing. So I implemented it and, much to my surprise, it worked. On 5/22/10 8:02 PM, "Fritz Anderson" <fri...@manoverboard.org> wrote: > On 22 May 2010, at 4:30 PM, Gordon Apple wrote: > >> So far, I don't see what I need for enabling/disabling undo/redo buttons in >> iPhoneOS NSUndoManager. I want to implement an undo button/popover, a la >> Pages, for a UITextView. I know I can read canUndo/canRedo, but I need an >> active notification when undo status changes in order to enable/disable the >> button and popover action buttons. What is the best way to get this, >> preferably without subclassing UITextView? Available notifications don't >> seem to be what I need. >> >> (MacOS usually does this when dropping a menu. That doesn't work here.) > > Tell us how the NSUndoManager...Notifications don't work for you. They apply > only to actual undo/redo events, and the opening and closing of undo groups, > but I'd have enough hope that the UIKit text system aggregated change events > that I'd test to see if those notifications came through. Have you done that? > > Analogies to Mac OS menu validations don't work. It's pretty plain that Apple > _really_ doesn't want to see menus in iPhone OS applications. > > Pages can do it (technically) because it doesn't rely on the text controls to > modify text. Everything goes through the Pages event loop, so it knows > independently whether something has been modified. > > Pages can do it as UI, on Apple's long-standing user-experience principle of > Quod Licet Jovi Non Licet Bovi. > > If you really needed it, you could hold your nose and poll every half-second > or so. > > F > _______________________________________________ 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
