// // $Id$ // // SPNotLoaded.m // sequel-pro // // Created by Rowan Beentje on 07/10/2009. // Copyright 2009 Rowan Beentje. All rights reserved. // // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 2 of the License, or // (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA // // More info at <http://code.google.com/p/sequel-pro/> #import "SPNotLoaded.h" static SPNotLoaded *notLoaded = nil; @implementation SPNotLoaded // Return the singleton object + (SPNotLoaded *) notLoaded { @synchronized(self) { if (notLoaded == nil) { [[self alloc] init]; } } return notLoaded; } + (id) allocWithZone:(NSZone *)zone { @synchronized(self) { if (notLoaded == nil) { return [super allocWithZone:zone]; } } return notLoaded; } - (id) init { Class notLoadedClass = [self class]; @synchronized(notLoadedClass) { if (notLoaded == nil) { if (self = [super init]) { notLoaded = self; } } } return notLoaded; } - (id) copyWithZone:(NSZone *)zone { return self; } - (id) retain { return self; } - (NSUInteger) retainCount { return NSUIntegerMax; } - (void) release {} - (id) autorelease { return self; } @end /** * This Category is intended to allow easy testing of all objects for SPNotLoaded. */ @implementation NSObject (SPNotLoadedTest) - (BOOL) isSPNotLoaded { static id SPNotLoadedForComparison; if (!SPNotLoadedForComparison) SPNotLoadedForComparison = [SPNotLoaded notLoaded]; return (self == SPNotLoadedForComparison); } @end