1 files changed, 91 insertions, 0 deletions
diff --git a/Source/SPNotLoaded.m b/Source/SPNotLoaded.m
new file mode 100644
index 00000000..f8afda1b
--- /dev/null
+++ b/Source/SPNotLoaded.m
@@ -0,0 +1,91 @@
+//
+//  $Id$
+//
+//  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; }
+
+- (unsigned) retainCount { return UINT_MAX; }
+
+- (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
+\ No newline at end of file