> On Oct 9, 2014, at 21:13, Ken Thomases <k...@codeweavers.com> wrote: > > On Oct 9, 2014, at 10:56 PM, Randy Widell <randy.wid...@gmail.com> wrote: > >> I’m not sure I am having a hard time figuring this out and I am just not >> finding anything via Google. I am writing a NSTextFieldCell subclass and I >> want to recalculate the size whenever the string value changes via a >> binding. What I can’t seem to figure out is how to observe the change. I >> could register each instance with itself for change notifications, but that >> just seems like an odd way to go about it. Seems like it should be possible >> to just override setValue:forKeyPath:, but that never seems to be called. > > I would expect that the control will call -setObjectValue: on the cell when > it (the control) receives a new value via the binding. > > It may not be the case that the control ever gets -setValue:forKey: when the > property to which it is bound changes. That's one possible way for the > implementation to work, but as least as likely is for the control to have > -observeValueForKeyPath:… to be called on it because it was using KVO to > observe the property to which it is bound. > > In any case, the cell should be entirely insulated from the way in which the > control received its new value. When implementing a cell, you should not > need to care about bindings or whatever. > > Regards, > Ken >
Oh, man, thanks. I knew it had to be something straightforward. Yeah, the whole KVO route seemed like a weird way to go about it. Went down the wrong rabbit hole. Thanks! _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
