On Mar 14, 2013, at 11:22 AM, Pax <45rpmli...@googlemail.com> wrote:
> My issue is that I only want one instance of the Information class to be > loaded at a given time (and therefore only one information window on screen > at a given time). If the information window is already loaded and it is then > reselected from the menu then the existing window needs to be brought to the > front - nothing more. > I have currently resolved it by making my class a singleton - but that's not > the right answer because it means that I can't release information window and > its class when it gets closed, resulting in a minor leak (only minor because, > as a singleton, the instance is only ever loaded once anyway). IMHO the full belt-and-suspenders implementation of a singleton you’ve chosen — overriding alloc, retain, release, etc. — is overkill. I just implement singletons using a +sharedInstance method that looks like your +singleton. If I’m feeling paranoid I put an assertion into the -init method that the singleton doesn’t yet exist. An easy way to make a sort of “weak singleton” like what you want, is to (a) make the static singleton pointer variable non-retained, and (b) nil it out in the -dealloc method. That way your singleton object isn’t kept around permanently, and when it goes away it cleans up so that the next request will instantiate a new one. (Of course you do have to ensure that *something* retains your singleton object as long as it needs to stay around, or else it’ll get dealloced very soon after being created and lose its state. —Jens _______________________________________________ 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
