UIColor-Expanded.m

#import "UIColor-Expanded.h"

/*
 
 Thanks to Poltras, Millenomi, Eridius, Nownot, WhatAHam, jberry,
 and everyone else who helped out but whose name is inadvertantly omitted
 
*/

/*
 Current outstanding request list:
 
 - PolarBearFarm - color descriptions ([UIColor warmGrayWithHintOfBlueTouchOfRedAndSplashOfYellowColor])
 - Crayola color set
 - Eridius - UIColor needs a method that takes 2 colors and gives a third complementary one
 - Consider UIMutableColor that can be adjusted (brighter, cooler, warmer, thicker-alpha, etc)
 */

/*
 FOR REFERENCE: Color Space Models: enum CGColorSpaceModel {
	kCGColorSpaceModelUnknown = -1,
	kCGColorSpaceModelMonochrome,
	kCGColorSpaceModelRGB,
	kCGColorSpaceModelCMYK,
	kCGColorSpaceModelLab,
	kCGColorSpaceModelDeviceN,
	kCGColorSpaceModelIndexed,
	kCGColorSpaceModelPattern
};
*/

static const char *colorNameDB;

// Complete dictionary of color name -> color mappings, generated
// by a call to +namedColors or +colorWithName:
static NSDictionary *colorNameCache = nil;
static NSLock *colorNameCacheLock;

#if SUPPORTS_UNDOCUMENTED_API
// UIColor_Undocumented
// Undocumented methods of UIColor
@interface UIColor (UIColor_Undocumented)
- (NSString *)styleString;
@end
#endif // SUPPORTS_UNDOCUMENTED_API

@interface UIColor (UIColor_Expanded_Support)
+ (void)populateColorNameCache;
@end

#pragma mark -

@implementation UIColor (UIColor_Expanded)

- (CGColorSpaceModel)colorSpaceModel {
	return CGColorSpaceGetModel(CGColorGetColorSpace(self.CGColor));
}

- (NSString *)colorSpaceString {
	switch (self.colorSpaceModel) {
		case kCGColorSpaceModelUnknown:
			return @"kCGColorSpaceModelUnknown";
		case kCGColorSpaceModelMonochrome:
			return @"kCGColorSpaceModelMonochrome";
		case kCGColorSpaceModelRGB:
			return @"kCGColorSpaceModelRGB";
		case kCGColorSpaceModelCMYK:
			return @"kCGColorSpaceModelCMYK";
		case kCGColorSpaceModelLab:
			return @"kCGColorSpaceModelLab";
		case kCGColorSpaceModelDeviceN:
			return @"kCGColorSpaceModelDeviceN";
		case kCGColorSpaceModelIndexed:
			return @"kCGColorSpaceModelIndexed";
		case kCGColorSpaceModelPattern:
			return @"kCGColorSpaceModelPattern";
		default:
			return @"Not a valid color space";
	}
}

- (BOOL)canProvideRGBComponents {
	switch (self.colorSpaceModel) {
		case kCGColorSpaceModelRGB:
		case kCGColorSpaceModelMonochrome:
			return YES;
		default:
			return NO;
	}
}

- (NSArray *)arrayFromRGBAComponents {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -arrayFromRGBAComponents");

	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
	
	return [NSArray arrayWithObjects:
			[NSNumber numberWithFloat:r],
			[NSNumber numberWithFloat:g],
			[NSNumber numberWithFloat:b],
			[NSNumber numberWithFloat:a],
			nil];
}

- (BOOL)red:(CGFloat *)red green:(CGFloat *)green blue:(CGFloat *)blue alpha:(CGFloat *)alpha {
	const CGFloat *components = CGColorGetComponents(self.CGColor);
	
	CGFloat r,g,b,a;
	
	switch (self.colorSpaceModel) {
		case kCGColorSpaceModelMonochrome:
			r = g = b = components[0];
			a = components[1];
			break;
		case kCGColorSpaceModelRGB:
			r = components[0];
			g = components[1];
			b = components[2];
			a = components[3];
			break;
		default:	// We don't know how to handle this model
			return NO;
	}
	
	if (red) *red = r;
	if (green) *green = g;
	if (blue) *blue = b;
	if (alpha) *alpha = a;
	
	return YES;
}

- (BOOL)hue:(CGFloat *)hue saturation:(CGFloat *)saturation brightness:(CGFloat *)brightness alpha:(CGFloat *)alpha {
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return NO;
	
	[UIColor red:r green:g blue:b toHue:hue saturation:saturation brightness:brightness];
	
	if (alpha) *alpha = a;
	
	return YES;
}

- (CGFloat)red {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -red");
	const CGFloat *c = CGColorGetComponents(self.CGColor);
	return c[0];
}

- (CGFloat)green {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -green");
	const CGFloat *c = CGColorGetComponents(self.CGColor);
	if (self.colorSpaceModel == kCGColorSpaceModelMonochrome) return c[0];
	return c[1];
}

- (CGFloat)blue {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -blue");
	const CGFloat *c = CGColorGetComponents(self.CGColor);
	if (self.colorSpaceModel == kCGColorSpaceModelMonochrome) return c[0];
	return c[2];
}

- (CGFloat)white {
	NSAssert(self.colorSpaceModel == kCGColorSpaceModelMonochrome, @"Must be a Monochrome color to use -white");
	const CGFloat *c = CGColorGetComponents(self.CGColor);
	return c[0];
}

- (CGFloat)hue {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -hue");
	CGFloat h = 0.0f;
	[self hue:&h saturation:nil brightness:nil alpha:nil];
	return h;
}

- (CGFloat)saturation {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -saturation");
	CGFloat s = 0.0f;
	[self hue:nil saturation:&s brightness:nil alpha:nil];
	return s;
}

- (CGFloat)brightness {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -brightness");
	CGFloat v = 0.0f;
	[self hue:nil saturation:nil brightness:&v alpha:nil];
	return v;
}

- (CGFloat)alpha {
	return CGColorGetAlpha(self.CGColor);
}

- (CGFloat)luminance {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use luminance");

	CGFloat r,g,b;
	if (![self red:&r green:&g blue:&b alpha:nil]) return 0.0f;
	
	// http://en.wikipedia.org/wiki/Luma_(video)
	// Y = 0.2126 R + 0.7152 G + 0.0722 B
	
	return r*0.2126f + g*0.7152f + b*0.0722f;
}

- (UInt32)rgbHex {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use rgbHex");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return 0;
	
	r = MIN(MAX(r, 0.0f), 1.0f);
	g = MIN(MAX(g, 0.0f), 1.0f);
	b = MIN(MAX(b, 0.0f), 1.0f);
	
	return (((int)roundf(r * 255)) << 16)
	     | (((int)roundf(g * 255)) << 8)
	     | (((int)roundf(b * 255)));
}

#pragma mark Arithmetic operations

- (UIColor *)colorByLuminanceMapping {
	return [UIColor colorWithWhite:self.luminance alpha:1.0f];
}

- (UIColor *)colorByMultiplyingByRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");

	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
		
	return [UIColor colorWithRed:MAX(0.0, MIN(1.0, r * red))
						   green:MAX(0.0, MIN(1.0, g * green)) 
							blue:MAX(0.0, MIN(1.0, b * blue))
						   alpha:MAX(0.0, MIN(1.0, a * alpha))];
}

- (UIColor *)colorByAddingRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
	
	return [UIColor colorWithRed:MAX(0.0, MIN(1.0, r + red))
						   green:MAX(0.0, MIN(1.0, g + green)) 
							blue:MAX(0.0, MIN(1.0, b + blue))
						   alpha:MAX(0.0, MIN(1.0, a + alpha))];
}

- (UIColor *)colorByLighteningToRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
		
	return [UIColor colorWithRed:MAX(r, red)
						   green:MAX(g, green)
							blue:MAX(b, blue)
						   alpha:MAX(a, alpha)];
}

- (UIColor *)colorByDarkeningToRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
	
	return [UIColor colorWithRed:MIN(r, red)
						   green:MIN(g, green)
							blue:MIN(b, blue)
						   alpha:MIN(a, alpha)];
}

- (UIColor *)colorByMultiplyingBy:(CGFloat)f {
	return [self colorByMultiplyingByRed:f green:f blue:f alpha:1.0f];
}

- (UIColor *)colorByAdding:(CGFloat)f {
	return [self colorByAddingRed:f green:f blue:f alpha:0.0f];
}

- (UIColor *)colorByLighteningTo:(CGFloat)f {
	return [self colorByLighteningToRed:f green:f blue:f alpha:0.0f];
}

- (UIColor *)colorByDarkeningTo:(CGFloat)f {
	return [self colorByDarkeningToRed:f green:f blue:f alpha:1.0f];
}

- (UIColor *)colorByMultiplyingByColor:(UIColor *)color {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
	
	return [self colorByMultiplyingByRed:r green:g blue:b alpha:1.0f];
}

- (UIColor *)colorByAddingColor:(UIColor *)color {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
	
	return [self colorByAddingRed:r green:g blue:b alpha:0.0f];
}

- (UIColor *)colorByLighteningToColor:(UIColor *)color {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
		
	return [self colorByLighteningToRed:r green:g blue:b alpha:0.0f];
}

- (UIColor *)colorByDarkeningToColor:(UIColor *)color {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmetic operations");
	
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
	
	return [self colorByDarkeningToRed:r green:g blue:b alpha:1.0f];
}

#pragma mark Complementary Colors, etc

// Pick a color that is likely to contrast well with this color
- (UIColor *)contrastingColor {
	return (self.luminance > 0.5f) ? [UIColor blackColor] : [UIColor whiteColor];
}

// Pick the color that is 180 degrees away in hue
- (UIColor *)complementaryColor {
	
	// Convert to HSB
	CGFloat h,s,v,a;
	if (![self hue:&h saturation:&s brightness:&v alpha:&a]) return nil;
		
	// Pick color 180 degrees away
	h += 180.0f;
	if (h > 360.f) h -= 360.0f;
	
	// Create a color in RGB
	return [UIColor colorWithHue:h saturation:s brightness:v alpha:a];
}

// Pick two colors more colors such that all three are equidistant on the color wheel
// (120 degrees and 240 degress difference in hue from self)
- (NSArray*)triadicColors {
	return [self analogousColorsWithStepAngle:120.0f pairCount:1];
}

// Pick n pairs of colors, stepping in increasing steps away from this color around the wheel
- (NSArray*)analogousColorsWithStepAngle:(CGFloat)stepAngle pairCount:(int)pairs {
	// Convert to HSB
	CGFloat h,s,v,a;
	if (![self hue:&h saturation:&s brightness:&v alpha:&a]) return nil;
	
	NSMutableArray* colors = [NSMutableArray arrayWithCapacity:pairs * 2];
	
	if (stepAngle < 0.0f)
		stepAngle *= -1.0f;
	
	for (int i = 1; i <= pairs; ++i) {
		CGFloat angle = fmodf(stepAngle * i, 360.0f);
		
		CGFloat h1 = fmodf(h + angle, 360.0f);
		CGFloat h2 = fmodf(h + 360.0f - angle, 360.0f);
		
		[colors addObject:[UIColor colorWithHue:h1 saturation:s brightness:v alpha:a]];
		[colors addObject:[UIColor colorWithHue:h2 saturation:s brightness:v alpha:a]];
	}
	
	return [[colors copy] autorelease];
}

#pragma mark String utilities

- (NSString *)stringFromColor {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -stringFromColor");
	NSString *result;
	switch (self.colorSpaceModel) {
		case kCGColorSpaceModelRGB:
			result = [NSString stringWithFormat:@"{%0.3f, %0.3f, %0.3f, %0.3f}", self.red, self.green, self.blue, self.alpha];
			break;
		case kCGColorSpaceModelMonochrome:
			result = [NSString stringWithFormat:@"{%0.3f, %0.3f}", self.white, self.alpha];
			break;
		default:
			result = nil;
	}
	return result;
}

- (NSString *)hexStringFromColor {
	return [NSString stringWithFormat:@"%0.6X", self.rgbHex];
}

- (NSString *)cssStringFromColor {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use cssStringFromColor");
    
	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return @"rgba(0,0,0,1)";

	return [NSString stringWithFormat:@"rgba(%d,%d,%d,%g)", (int)(r*255.0f),(int)(g*255.0f),(int)(b*255.0f),a];
}

- (NSString *)closestColorName {
	NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use closestColorName");
	
	int targetHex = self.rgbHex;
	int rInt = (targetHex >> 16) & 0x0ff;
	int gInt = (targetHex >> 8) & 0x0ff;
	int bInt = (targetHex >> 0) & 0x0ff;
	
	float bestScore = MAXFLOAT;
	const char* bestPos = nil;
	
	// Walk the colorNameDB looking for the name with closest match
	for (const char* p = colorNameDB; (p = strchr(p, '#')); ++p) {
		int r,g,b;
		if (sscanf(p+1, "%2x%2x%2x", &r, &g, &b) == 3) {
			// Calculate difference between this color and the target color
			int rDiff = abs(rInt - r);
			int gDiff = abs(gInt - g);
			int bDiff = abs(bInt - b);
			float score = logf(rDiff+1) + logf(gDiff+1) + logf(bDiff+1);
			
			// Track the best score/name seen
			if (score < bestScore) {
				bestScore = score;
				bestPos = p;
			}
		}
	}
	
	// bestPos now points to the # following the best name seen
	// Backup to the start of the name and return it
	const char* name;
	for (name = bestPos-1; *name != ','; --name)
		;
	++name;
	NSString *result = [[[NSString alloc] initWithBytes:name length:bestPos - name encoding:NSUTF8StringEncoding] autorelease];

	return result;
}

+ (UIColor *)colorWithString:(NSString *)stringToConvert {
	NSScanner *scanner = [NSScanner scannerWithString:stringToConvert];
	if (![scanner scanString:@"{" intoString:NULL]) return nil;
	const NSUInteger kMaxComponents = 4;
	CGFloat c[kMaxComponents];
	NSUInteger i = 0;
	if (![scanner scanFloat:&c[i++]]) return nil;
	while (1) {
		if ([scanner scanString:@"}" intoString:NULL]) break;
		if (i >= kMaxComponents) return nil;
		if ([scanner scanString:@"," intoString:NULL]) {
			if (![scanner scanFloat:&c[i++]]) return nil;
		} else {
			// either we're at the end of there's an unexpected character here
			// both cases are error conditions
			return nil;
		}
	}
	if (![scanner isAtEnd]) return nil;
	UIColor *color;
	switch (i) {
		case 2: // monochrome
			color = [UIColor colorWithWhite:c[0] alpha:c[1]];
			break;
		case 4: // RGB
			color = [UIColor colorWithRed:c[0] green:c[1] blue:c[2] alpha:c[3]];
			break;
		default:
			color = nil;
	}
	return color;
}

#pragma mark Class methods

+ (UIColor *)randomColor {
	return [UIColor colorWithRed:(arc4random() % ((unsigned)RAND_MAX + 1)) / (CGFloat)RAND_MAX
						   green:(arc4random() % ((unsigned)RAND_MAX + 1)) / (CGFloat)RAND_MAX
							blue:(arc4random() % ((unsigned)RAND_MAX + 1)) / (CGFloat)RAND_MAX
						   alpha:1.0f];
}

+ (UIColor *)colorWithRGBHex:(UInt32)hex {
	int r = (hex >> 16) & 0xFF;
	int g = (hex >> 8) & 0xFF;
	int b = (hex) & 0xFF;
	
	return [UIColor colorWithRed:r / 255.0f
						   green:g / 255.0f
							blue:b / 255.0f
						   alpha:1.0f];
}

+ (UIColor *)colorWithGray:(CGFloat)gray {
	return [UIColor colorWithWhite:gray alpha:1.0f];
}

+ (UIColor *)colorWithGrayHex:(UInt8)gray {
	return [UIColor colorWithWhite:gray / 255.0f alpha:1.0f];
}

// Returns a UIColor by scanning the string for a hex number and passing that to +[UIColor colorWithRGBHex:]
// Skips any leading whitespace and ignores any trailing characters
+ (UIColor *)colorWithHexString:(NSString *)stringToConvert {
	NSScanner *scanner = [NSScanner scannerWithString:stringToConvert];
	unsigned hexNum;
	if (![scanner scanHexInt:&hexNum]) return nil;
	return [UIColor colorWithRGBHex:hexNum];
}

// Lookup a color using css 3/svg color name
+ (UIColor *)colorWithName:(NSString *)cssColorName {
	return [[UIColor namedColors] objectForKey:cssColorName];
}

+ (UIColor *)colorWithCSSDescription:(NSString *)cssDescription {
	// CSS syntax is
	//	#fff
	//	#ffffff
	//	rgb(100, 200 ,255)
	//	rgb(1%,50% , 30% )
	//	rgba(100, 200,255, 0.5)
	//	hsl(260,50%,40%)
	//	hsla(260,50%,40%,0.8)
	//	colorName
	
	NSScanner* scanner = [NSScanner scannerWithString:cssDescription];
	BOOL withAlpha = NO;
	
	// Look for determining characteristics of the string
	if ([scanner scanString:@"#" intoString:nil]) {
		
		// A hex string like #fff or #ffffff
		
		unsigned int hex = 0;
		if (![scanner scanHexInt:&hex]) return nil;
		if (![scanner isAtEnd]) return nil;
		
		int hexLen = [scanner scanLocation] - 1;
		if (hexLen == 3) {
			// A 3 digit hex num
			int r = (hex >> 8) & 0xF;
			int g = (hex >> 4) & 0xF;
			int b = (hex) & 0xF;
			return [UIColor colorWithRed:r / 15.0f
								   green:g / 15.0f
									blue:b / 15.0f
								   alpha:1.0f];
		} else if (hexLen == 6) {
			// A 6 digit hex num
			return [self colorWithRGBHex:hex];
		} else {
			// An unsupported number of digits
			return nil;
		}
		
	} else if ([scanner scanString:@"rgb(" intoString:nil] || (withAlpha = [scanner scanString:@"rgba(" intoString:nil])) {
		
		// It's an rgb color spec like rgb( 100,200, 50) or rgb(50%, 30%, 20%), or rgba(100,200,50,0.8)

		// skip whitespace characters in coming processing
		[scanner setCharactersToBeSkipped:[NSCharacterSet whitespaceCharacterSet]];
				
		// Read 3 comma-separated floats, each with potentially trailing % sign
		float rgb[3];
		for (int i = 0; i < 3; ++i) {
			if (![scanner scanFloat:&rgb[i]]) return nil;
			if ([scanner scanString:@"%" intoString:nil])
				rgb[i] = (rgb[i] / 100.0f) * 255.0f;
			if (i < 2 && ![scanner scanString:@"," intoString:nil]) return nil;
		}
		
		// Read an alpha value if requested
		float alpha = 1.0f;
		if (withAlpha) {
			if (![scanner scanString:@"," intoString:nil]) return nil;
			if (![scanner scanFloat:&alpha]) return nil;
		}
		
		// Verify end of string
		if (![scanner scanString:@")" intoString:nil]) return nil;
		if (![scanner isAtEnd]) return nil;
		
		// Form the color, pinning the numbers into range
		return [UIColor colorWithRed:MAX(0.0, MIN(1.0, rgb[0] / 255.0f))
							   green:MAX(0.0, MIN(1.0, rgb[1] / 255.0f))
								blue:MAX(0.0, MIN(1.0, rgb[2] / 255.0f))
							   alpha:MAX(0.0, MIN(1.0, alpha))];
		
	} else if ([scanner scanString:@"hsl(" intoString:nil] || (withAlpha = [scanner scanString:@"hsla(" intoString:nil])) {
		
		// It's an hsl color spec like hsl(260,50%,40%) or hsla(260,50%,40%,0.8)
		
		// skip whitespace characters in coming processing
		[scanner setCharactersToBeSkipped:[NSCharacterSet whitespaceCharacterSet]];
		
		// Hue
		float hue;
		if (![scanner scanFloat:&hue]) return nil;
		
		// Saturation
		float saturation;
		if (![scanner scanString:@"," intoString:nil]) return nil;
		if (![scanner scanFloat:&saturation]) return nil;
		if (![scanner scanString:@"%" intoString:nil]) return nil;
		
		// Brightness
		float lightness;
		if (![scanner scanString:@"," intoString:nil]) return nil;
		if (![scanner scanFloat:&lightness]) return nil;
		if (![scanner scanString:@"%" intoString:nil]) return nil;
		
		// Read an alpha value if requested
		float alpha = 1.0f;
		if (withAlpha) {
			if (![scanner scanString:@"," intoString:nil]) return nil;
			if (![scanner scanFloat:&alpha]) return nil;
		}
		
		// Verify end of string
		if (![scanner scanString:@")" intoString:nil]) return nil;
		if (![scanner isAtEnd]) return nil;
		
		// Form the color, pinning the numbers into range
		return [UIColor colorWithHue:MAX(0.0, MIN(360.0, hue))
						  saturation:MAX(0.0, MIN(1.0, saturation / 100.0f))
						   lightness:MAX(0.0, MIN(1.0, lightness / 100.0f))
							   alpha:MAX(0.0, MIN(1.0, alpha))];
		
	} else {
		// Assume it's a css color name
		return [self colorWithName:cssDescription];
	}
}

// Return complete mapping of css3/svg color names --> colors
+ (NSDictionary *)namedColors {
	[colorNameCacheLock lock];
	if (colorNameCache == nil) [UIColor populateColorNameCache];
	[colorNameCacheLock unlock];
	return colorNameCache;
}

+ (UIColor *)colorWithHue:(CGFloat)hue saturation:(CGFloat)saturation brightness:(CGFloat)brightness alpha:(CGFloat)alpha {
	// Convert hsb to rgb
	CGFloat r,g,b;
	[self hue:hue saturation:saturation brightness:brightness toRed:&r green:&g blue:&b];
	
	// Create a color with rgb
	return [self colorWithRed:r green:g blue:b alpha:alpha];
}


+ (UIColor *)colorWithHue:(CGFloat)hue saturation:(CGFloat)saturation lightness:(CGFloat)lightness alpha:(CGFloat)alpha {
	// Convert from hsl to hsb (hsv)
	CGFloat h = hue;	
	saturation *= (lightness <= 0.5f) ? lightness : 1 - lightness;
	CGFloat v = lightness + saturation;
	CGFloat s = (v != 0.0f) ? (2 * saturation) / v : 0.0f;		// avoid division by zero

	// Convert from hsb to rgb
	CGFloat r,g,b;
	[self hue:h saturation:s brightness:v toRed:&r green:&g blue:&b];
	
	// Create a color with rgb
	return [self colorWithRed:r green:g blue:b alpha:alpha];
}


#pragma mark Color Space Conversions

+ (void)hue:(CGFloat)h saturation:(CGFloat)s brightness:(CGFloat)v toRed:(CGFloat *)pR green:(CGFloat *)pG blue:(CGFloat *)pB {
	CGFloat r,g,b;
	
	// From Foley and Van Dam
	
	if (s == 0.0f) {
		// Achromatic color: there is no hue
		r = g = b = v;
	} else {
		// Chromatic color: there is a hue
		if (h == 360.0f) h = 0.0f;
		h /= 60.0f;										// h is now in [0, 6)
		
		int i = floorf(h);								// largest integer <= h
		CGFloat f = h - i;								// fractional part of h
		CGFloat p = v * (1 - s);
		CGFloat q = v * (1 - (s * f));
		CGFloat t = v * (1 - (s * (1 - f)));
		
		switch (i) {
			case 0:	r = v; g = t; b = p;	break;
			case 1:	r = q; g = v; b = p;	break;
			case 2:	r = p; g = v; b = t;	break;
			case 3:	r = p; g = q; b = v;	break;
			case 4:	r = t; g = p; b = v;	break;
			case 5:	r = v; g = p; b = q;	break;
			default: r = g = b = 0.0f;		break;		// Keep analyzer happy
		}
	}
	
	if (pR) *pR = r;
	if (pG) *pG = g;
	if (pB) *pB = b;
}


+ (void)red:(CGFloat)r green:(CGFloat)g blue:(CGFloat)b toHue:(CGFloat *)pH saturation:(CGFloat *)pS brightness:(CGFloat *)pV {
	CGFloat h,s,v;
	
	// From Foley and Van Dam
	
	CGFloat max = MAX(r, MAX(g, b));
	CGFloat min = MIN(r, MIN(g, b));
	
	// Brightness
	v = max;
	
	// Saturation
	s = (max != 0.0f) ? ((max - min) / max) : 0.0f;
	
	// Hue
	if (s == 0.0f) {
		// No saturation, so undefined hue
		h = 0.0f;
	} else {
		// Determine hue
		CGFloat delta = max - min;
		
		if (r == max) {
			h = (g - b) / delta;					// resulting color between yellow and magenta
		} else if (g == max) {
			h = 2.0f + (b - r) / delta;				// resulting color between cyan and yellow
		} else /* if (b == max) */ {
			h = 4.0f + (r - g) / delta;				// resulting color between magenta and cyan
		}
		
		h *= 60.0f;									// Convert to degrees
		if (h < 0.0f) h += 360.0f;					// Make non-negative
	}
	
	if (pH) *pH = h;
	if (pS) *pS = s;
	if (pV) *pV = v;
}


#pragma mark UIColor_Expanded initialization

+ (void)load {
	colorNameCacheLock = [[NSLock alloc] init];
}

@end

#pragma mark -

#if SUPPORTS_UNDOCUMENTED_API
@implementation UIColor (UIColor_Undocumented_Expanded)
- (NSString *)fetchStyleString {
	return [self styleString];
}

// Convert a color into RGB Color space, courtesy of Poltras
// via http://ofcodeandmen.poltras.com/2009/01/22/convert-a-cgcolorref-to-another-cgcolorspaceref/
//
- (UIColor *)rgbColor {
	// Call to undocumented method "styleString".
	NSString *style = [self styleString];
	NSScanner *scanner = [NSScanner scannerWithString:style];
	CGFloat red, green, blue;
	if (![scanner scanString:@"rgb(" intoString:NULL]) return nil;
	if (![scanner scanFloat:&red]) return nil;
	if (![scanner scanString:@"," intoString:NULL]) return nil;
	if (![scanner scanFloat:&green]) return nil;
	if (![scanner scanString:@"," intoString:NULL]) return nil;
	if (![scanner scanFloat:&blue]) return nil;
	if (![scanner scanString:@")" intoString:NULL]) return nil;
	if (![scanner isAtEnd]) return nil;
	
	return [UIColor colorWithRed:red green:green blue:blue alpha:self.alpha];
}
@end
#endif // SUPPORTS_UNDOCUMENTED_API

@implementation UIColor (UIColor_Expanded_Support)
/*
 * Database of color names and hex rgb values, derived
 * from the css 3 color spec:
 *	http://www.w3.org/TR/css3-color/
 *
 * We think this is a very compact way of storing
 * this information, and relatively cheap to lookup.
 *
 * Note that we search for color names starting with ','
 * and terminated by '#', so that we don't get false matches.
 * For this reason, the database begins with ','.
 */
static const char *colorNameDB = ","
	"aliceblue#f0f8ff,antiquewhite#faebd7,aqua#00ffff,aquamarine#7fffd4,azure#f0ffff,"
	"beige#f5f5dc,bisque#ffe4c4,black#000000,blanchedalmond#ffebcd,blue#0000ff,"
	"blueviolet#8a2be2,brown#a52a2a,burlywood#deb887,cadetblue#5f9ea0,chartreuse#7fff00,"
	"chocolate#d2691e,coral#ff7f50,cornflowerblue#6495ed,cornsilk#fff8dc,crimson#dc143c,"
	"cyan#00ffff,darkblue#00008b,darkcyan#008b8b,darkgoldenrod#b8860b,darkgray#a9a9a9,"
	"darkgreen#006400,darkgrey#a9a9a9,darkkhaki#bdb76b,darkmagenta#8b008b,"
	"darkolivegreen#556b2f,darkorange#ff8c00,darkorchid#9932cc,darkred#8b0000,"
	"darksalmon#e9967a,darkseagreen#8fbc8f,darkslateblue#483d8b,darkslategray#2f4f4f,"
	"darkslategrey#2f4f4f,darkturquoise#00ced1,darkviolet#9400d3,deeppink#ff1493,"
	"deepskyblue#00bfff,dimgray#696969,dimgrey#696969,dodgerblue#1e90ff,"
	"firebrick#b22222,floralwhite#fffaf0,forestgreen#228b22,fuchsia#ff00ff,"
	"gainsboro#dcdcdc,ghostwhite#f8f8ff,gold#ffd700,goldenrod#daa520,gray#808080,"
	"green#008000,greenyellow#adff2f,grey#808080,honeydew#f0fff0,hotpink#ff69b4,"
	"indianred#cd5c5c,indigo#4b0082,ivory#fffff0,khaki#f0e68c,lavender#e6e6fa,"
	"lavenderblush#fff0f5,lawngreen#7cfc00,lemonchiffon#fffacd,lightblue#add8e6,"
	"lightcoral#f08080,lightcyan#e0ffff,lightgoldenrodyellow#fafad2,lightgray#d3d3d3,"
	"lightgreen#90ee90,lightgrey#d3d3d3,lightpink#ffb6c1,lightsalmon#ffa07a,"
	"lightseagreen#20b2aa,lightskyblue#87cefa,lightslategray#778899,"
	"lightslategrey#778899,lightsteelblue#b0c4de,lightyellow#ffffe0,lime#00ff00,"
	"limegreen#32cd32,linen#faf0e6,magenta#ff00ff,maroon#800000,mediumaquamarine#66cdaa,"
	"mediumblue#0000cd,mediumorchid#ba55d3,mediumpurple#9370db,mediumseagreen#3cb371,"
	"mediumslateblue#7b68ee,mediumspringgreen#00fa9a,mediumturquoise#48d1cc,"
	"mediumvioletred#c71585,midnightblue#191970,mintcream#f5fffa,mistyrose#ffe4e1,"
	"moccasin#ffe4b5,navajowhite#ffdead,navy#000080,oldlace#fdf5e6,olive#808000,"
	"olivedrab#6b8e23,orange#ffa500,orangered#ff4500,orchid#da70d6,palegoldenrod#eee8aa,"
	"palegreen#98fb98,paleturquoise#afeeee,palevioletred#db7093,papayawhip#ffefd5,"
	"peachpuff#ffdab9,peru#cd853f,pink#ffc0cb,plum#dda0dd,powderblue#b0e0e6,"
	"purple#800080,red#ff0000,rosybrown#bc8f8f,royalblue#4169e1,saddlebrown#8b4513,"
	"salmon#fa8072,sandybrown#f4a460,seagreen#2e8b57,seashell#fff5ee,sienna#a0522d,"
	"silver#c0c0c0,skyblue#87ceeb,slateblue#6a5acd,slategray#708090,slategrey#708090,"
	"snow#fffafa,springgreen#00ff7f,steelblue#4682b4,tan#d2b48c,teal#008080,"
	"thistle#d8bfd8,tomato#ff6347,turquoise#40e0d0,violet#ee82ee,wheat#f5deb3,"
	"white#ffffff,whitesmoke#f5f5f5,yellow#ffff00,yellowgreen#9acd32";

+ (void)populateColorNameCache {
	NSAssert(colorNameCache == nil, @"+pouplateColorNameCache was called when colorNameCache was not nil");
	NSMutableDictionary *cache = [NSMutableDictionary dictionary];
	for (const char* entry = colorNameDB; (entry = strchr(entry, ',')); ) {
		
		// Step forward to the start of the name
		++entry;
		
		// Find the following hash
		const char* h = strchr(entry, '#');
		NSAssert(h, @"Malformed colorNameDB");
		
		// Get the name
		NSString* name = [[NSString alloc] initWithBytes:entry length:h - entry encoding:NSUTF8StringEncoding];
		
		// Get the color, and add to the dictionary
		int hex, increment;
		int scanCount = sscanf(++h, "%x%n", &hex, &increment);
		NSAssert(scanCount == 1, @"malformed colorNameDB");
		
		[cache setObject:[self colorWithRGBHex:hex] forKey:name];
		
		// Cleanup and move to the next item
		[name release];
		entry = h + increment;
	}
	
	// Additionally, add the color named "transparent"
	[cache setObject:[self colorWithRed:0 green:0 blue:0 alpha:0] forKey:@"transparent"];
	
	colorNameCache = [cache copy];
}
@end