On 7. 6. 2013., at 10:47, David Chisnall <thera...@sucs.org> wrote: > On 7 Jun 2013, at 09:42, Maxthon Chan <xcvi...@me.com> wrote: > >> Well can I (just like NSApplication): >> >> 1) In supercalss, define the shared instance as id >> 2) In superclass, return the shared instance as id or instancetype >> 3) In superclass, DO NOT set up yet. >> 4) In superclass, set up in the method asking for the shared instance, which >> always use [[self alloc] init]? > > NSApplication is an example of a singleton designed for subclassing. It > provides an explicit mechanism for defining the subclass that should be used > for the singleton instance: a string in the Info.plist providing the name of > the application class to use. It also sets up its delegate in this way and > gets the name of the nib to load on application start. > > David > > -- Sent from my brain >
Also notable is NSDocumentController, which is explicitly being overridden by [MyDocumentController sharedController] before first use by either the app or the framework; that is, in -applicationWillFinishLaunching:. I do this to prevent the user from opening more than one document while still leveraging other parts of the document architecture. Regards, Ivan Vučica via phone _______________________________________________ Gnustep-dev mailing list Gnustep-dev@gnu.org https://lists.gnu.org/mailman/listinfo/gnustep-dev
