OrderedDictionary.h

//
//  OrderedDictionary.h
//  OrderedDictionary
//
//  Created by Matt Gallagher on 19/12/08.
//  Copyright 2008 Matt Gallagher. All rights reserved.
//
//  Permission is given to use this source code file without charge in any
//  project, commercial or otherwise, entirely at your risk, with the condition
//  that any redistribution (in part or whole) of source code must retain
//  this copyright and permission notice. Attribution in compiled projects is
//  appreciated but not required.
//
//  HEAVILY modified by Zac Bowling (2011)
//  Copyright 2011 Zac Bowling


#import <Foundation/Foundation.h>

@interface MWOrderedDictionary : NSMutableDictionary
{
	NSMutableDictionary *dictionary;
	NSMutableArray *array;
	NSArray *cache;
}

- (NSArray *)asArray;
- (void)insertObject:(id)anObject forKey:(id)aKey;
- (void)insertObject:(id)anObject forKey:(id)aKey atIndex:(NSUInteger)anIndex;
- (id)keyAtIndex:(NSUInteger)anIndex;
- (NSEnumerator *)reverseKeyEnumerator;

@end

OrderedDictionary.m

//
//  OrderedDictionary.m
//  OrderedDictionary
//
//  Created by Matt Gallagher on 19/12/08.
//  Copyright 2008 Matt Gallagher. All rights reserved.
//
//  Permission is given to use this source code file without charge in any
//  project, commercial or otherwise, entirely at your risk, with the condition
//  that any redistribution (in part or whole) of source code must retain
//  this copyright and permission notice. Attribution in compiled projects is
//  appreciated but not required.
//
//  HEAVILY modified by Zac Bowling (2011)
//  Copyright 2011 Zac Bowling


#import "MWOrderedDictionary.h"

NSString *DescriptionForObject(NSObject *object, id locale, NSUInteger indent)
{
	NSString *objectString;
	if ([object isKindOfClass:[NSString class]])
	{
		objectString = (NSString *)[[object retain] autorelease];
	}
	else if ([object respondsToSelector:@selector(descriptionWithLocale:indent:)])
	{
		objectString = [(NSDictionary *)object descriptionWithLocale:locale indent:indent];
	}
	else if ([object respondsToSelector:@selector(descriptionWithLocale:)])
	{
		objectString = [(NSSet *)object descriptionWithLocale:locale];
	}
	else
	{
		objectString = [object description];
	}
	return objectString;
}

@implementation MWOrderedDictionary


- (id)init
{
	return [self initWithCapacity:0];
}

- (id)initWithCapacity:(NSUInteger)capacity
{
	self = [super init];
	if (self != nil)
	{
		dictionary = [[NSMutableDictionary alloc] initWithCapacity:capacity];
		array = [[NSMutableArray alloc] initWithCapacity:capacity];
		cache = nil;
	}
	return self;
}

- (void)dealloc
{
	[cache release];
	[dictionary release];
	[array release];
	[super dealloc];
}

- (id)copy
{
	return [self mutableCopy];
}

- (void)setObject:(id)anObject forKey:(id)aKey
{
	if (cache) {
		[cache release];
		cache = nil;
	}
	if (![dictionary objectForKey:aKey])
	{
		[array addObject:aKey];
	}
	[dictionary setObject:anObject forKey:aKey];
}

- (void)removeObjectForKey:(id)aKey
{
	if (cache) {
		[cache release];
		cache = nil;
	}
	[dictionary removeObjectForKey:aKey];
	[array removeObject:aKey];
}

- (NSUInteger)count
{
	return [dictionary count];
}

- (id)objectForKey:(id)aKey
{
	return [dictionary objectForKey:aKey];
}

- (NSEnumerator *)keyEnumerator
{
	return [array objectEnumerator];
}

- (NSEnumerator *)reverseKeyEnumerator
{
	return [array reverseObjectEnumerator];
}

- (void)insertObject:(id)anObject forKey:(id)aKey 
{
	[self setObject:anObject forKey:aKey]; 
}

- (void)insertObject:(id)anObject forKey:(id)aKey atIndex:(NSUInteger)anIndex
{
	if (cache) {
		[cache release];
		cache = nil;
	}
	
	if (![dictionary objectForKey:aKey])
	{
		[self removeObjectForKey:aKey];
	}
	[array insertObject:aKey atIndex:anIndex];
	[dictionary setObject:anObject forKey:aKey];
}

- (id)keyAtIndex:(NSUInteger)anIndex
{
	return [array objectAtIndex:anIndex];
}

- (NSString *)descriptionWithLocale:(id)locale indent:(NSUInteger)level
{
	NSMutableString *indentString = [NSMutableString string];
	NSUInteger i, count = level;
	for (i = 0; i < count; i++)
	{
		[indentString appendFormat:@"    "];
	}
	
	NSMutableString *description = [NSMutableString string];
	[description appendFormat:@"%@{\n", indentString];
	for (NSObject *key in self)
	{
		[description appendFormat:@"%@    %@ = %@;\n",
		 indentString,
		 DescriptionForObject(key, locale, level),
		 DescriptionForObject([self objectForKey:key], locale, level)];
	}
	[description appendFormat:@"%@}\n", indentString];
	return description;
}

- (NSArray *)asArray
{
	if (cache) 
		return cache;
	
	NSMutableArray* arrayCopy = [NSMutableArray arrayWithCapacity:[self count]];
	for (id item in self)
	{
		[arrayCopy addObject:[self objectForKey:item]];
	}
	
	cache = [arrayCopy retain];
	return cache;
}

@end