Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
branch: master
Fetching contributors…

Cannot retrieve contributors at this time

1176 lines (882 sloc) 35.607 kB
#import "UIColor+Expanded.h"
/*
Thanks to Poltras, Millenomi, Eridius, Nownot, WhatAHam, jberry,
and everyone else who helped out but whose name is inadvertantly omitted
*/
/* Static cache of looked up color names. Used with +colorWithName: */
static NSMutableDictionary *_ColorNameCache = nil;
static NSMutableDictionary *_CrayolaNameCache = nil;
@interface UIColor (Expanded_Private)
+ (UIColor *)__searchForColorByName:(NSString *)cssColorName;
+ (UIColor *)__searchForCrayolaByName:(NSString *)crayolaColorName;
@end
@implementation UIColor (Expanded)
+ (void)load {
_ColorNameCache = [[NSMutableDictionary alloc] init];
_CrayolaNameCache = [[NSMutableDictionary alloc] init];
}
- (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 = fminf(fmaxf(r, 0.0f), 1.0f);
g = fminf(fmaxf(g, 0.0f), 1.0f);
b = fminf(fmaxf(b, 0.0f), 1.0f);
return (UInt32) ((((int)roundf(r * 255)) << 16)
| (((int)roundf(g * 255)) << 8)
| (((int)roundf(b * 255))));
}
- (UInt32)rgbaHex {
NSAssert(self.canProvideRGBComponents, @"Must be a RGBA color to use rgbaHex");
CGFloat r,g,b,a;
if (![self red:&r green:&g blue:&b alpha:&a]) return 0;
r = fminf(fmaxf(self.red, 0.0f), 1.0f);
g = fminf(fmaxf(self.green, 0.0f), 1.0f);
b = fminf(fmaxf(self.blue, 0.0f), 1.0f);
a = fminf(fmaxf(self.alpha, 0.0f), 1.0f);
return (((int)roundf(r * 255)) << 24)
| (((int)roundf(g * 255)) << 16)
| (((int)roundf(b * 255)) << 8)
| (((int)roundf(b * 255)) );
}
#pragma mark Arithmetic operations
- (UIColor *)colorByLuminanceMapping {
NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmatic operations");
CGFloat r, g, b, a;
if (![self red:&r green:&g blue:&b alpha:&a]) {
return nil;
}
// http://en.wikipedia.org/wiki/Luma_(video)
// Y = 0.2126 R + 0.7152 G + 0.0722 B
return [UIColor colorWithWhite:r * 0.2126f + g * 0.7152f + b * 0.0722f alpha:a];
}
- (UIColor *)colorByMultiplyingByRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha {
NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmatic operations");
CGFloat r, g, b, a;
if (![self red:&r green:&g blue:&b alpha:&a]) {
return nil;
}
return [UIColor colorWithRed:(CGFloat)fmaxf(0.0f, fminf(1.0f, r * red))
green:(CGFloat)fmaxf(0.0f, fminf(1.0f, g * green))
blue:(CGFloat)fmaxf(0.0f, fminf(1.0f, b * blue))
alpha:(CGFloat)fmaxf(0.0f, fminf(1.0f, 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 arithmatic operations");
CGFloat r, g, b, a;
if (![self red:&r green:&g blue:&b alpha:&a]) {
return nil;
}
return [UIColor colorWithRed:(CGFloat)fmaxf(0.0f, fminf(1.0f, r + red))
green:(CGFloat)fmaxf(0.0f, fminf(1.0f, g + green))
blue:(CGFloat)fmaxf(0.0f, fminf(1.0f, b + blue))
alpha:(CGFloat)fmaxf(0.0f, fminf(1.0f, 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 arithmatic operations");
CGFloat r, g, b, a;
if (![self red:&r green:&g blue:&b alpha:&a]) {
return nil;
}
return [UIColor colorWithRed:fmaxf(r, red)
green:fmaxf(g, green)
blue:fmaxf(b, blue)
alpha:fmaxf(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 arithmatic operations");
CGFloat r, g, b, a;
if (![self red:&r green:&g blue:&b alpha:&a]) {
return nil;
}
return [UIColor colorWithRed:fminf(r, red)
green:fminf(g, green)
blue:fminf(b, blue)
alpha:fminf(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 arithmatic 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 arithmatic 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 arithmatic 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 arithmatic 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];
}
- (UIColor *)colorByInterpolatingToColor:(UIColor *)color byFraction:(CGFloat)fraction {
NSAssert(self.canProvideRGBComponents, @"Must be a RGB color to use arithmatic operations");
NSAssert(color.canProvideRGBComponents, @"Must be a RGB color to use arithmatic operations");
CGFloat r,g,b,a;
if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
CGFloat r2,g2,b2,a2;
if (![color red:&r2 green:&g2 blue:&b2 alpha:&a2]) return nil;
CGFloat red = r + (fraction * (r2 - r));
CGFloat green = g + (fraction * (g2 - g));
CGFloat blue = b + (fraction * (b2 - b));
CGFloat alpha = a + (fraction * (a2 - a));
UIColor *new = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
return new;
}
#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]];
}
#if __has_feature(objc_arc)
return [colors copy];
#else
return [[colors copy] autorelease];
#endif
}
#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", (unsigned int)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 *)closestColorNameFor:(const char *) aColorDatabase {
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 name db string looking for the name with closest match
for (const char* p = aColorDatabase; (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;
}
}
}
assert(bestPos);
// 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];
#if !__has_feature(objc_arc)
[result autorelease];
#endif
return result;
}
- (NSString *)closestColorName {
return [self closestColorNameFor:_ColorNameDB];
}
- (NSString *)closestCrayonName {
return [self closestColorNameFor:_CrayolaNameDB];
}
- (NSString *)hexStringFromColorAndAlpha {
return [NSString stringWithFormat:@"%0.8X", (unsigned int)self.rgbaHex];
}
+ (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 CGFLOAT_IS_DOUBLE
BOOL scanFloatResult = [scanner scanDouble:&c[i++]];
#else
BOOL scanFloatResult = [scanner scanFloat:&c[i++]];
#endif
if (!scanFloatResult) {
return nil;
}
while (1) {
if ([scanner scanString:@"}" intoString:NULL]) {
break;
}
if (i >= kMaxComponents) {
return nil;
}
if ([scanner scanString:@"," intoString:NULL]) {
#if CGFLOAT_IS_DOUBLE
BOOL scanFloatResult = [scanner scanDouble:&c[i++]];
#else
BOOL scanFloatResult = [scanner scanFloat:&c[i++]];
#endif
if (!scanFloatResult) {
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 *)randomHSBColor {
return [UIColor colorWithHue:random() / (CGFloat)RAND_MAX
saturation:random() / (CGFloat)RAND_MAX
brightness:random() / (CGFloat)RAND_MAX
alpha:1.0f];
}
+ (UIColor *)randomHSBColorWithMinSaturation:(CGFloat)minSat minBrightness:(CGFloat)minBright {
CGFloat hue = random() / (CGFloat)RAND_MAX;
CGFloat sat = ((random() / (CGFloat)RAND_MAX) * (1-minSat)) + minSat;
CGFloat brightness = ((random() / (CGFloat)RAND_MAX) * (1-minBright)) + minBright;
return [UIColor colorWithHue:hue
saturation:sat
brightness:brightness
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 *)colorWithRGBAHex:(UInt32)hex {
int r = (hex >> 24) & 0xFF;
int g = (hex >> 16) & 0xFF;
int b = (hex >> 8) & 0xFF;
int a = (hex) & 0xFF;
return [UIColor colorWithRed:r / 255.0f
green:g / 255.0f
blue:b / 255.0f
alpha:a / 255.0f];
}
+ (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 {
if ([stringToConvert hasPrefix:@"#"]) {
stringToConvert = [stringToConvert substringFromIndex:1];
}
NSScanner *scanner = [NSScanner scannerWithString:stringToConvert];
unsigned hexNum;
if (![scanner scanHexInt:&hexNum]) {
return nil;
}
return [UIColor colorWithRGBHex:hexNum];
}
// Returns a UIColor by scanning the string for a hex number and passing that to +[UIColor colorWithRGBAHex:]
// Skips any leading whitespace and ignores any trailing characters
+ (UIColor *)colorAndAlphaWithHexString:(NSString *)stringToConvert {
NSScanner *scanner = [NSScanner scannerWithString:stringToConvert];
unsigned hexNum;
if (![scanner scanHexInt:&hexNum]) return nil;
return [UIColor colorWithRGBAHex:hexNum];
}
// Lookup a color using css 3/svg color name
+ (UIColor *)colorWithName:(NSString *)cssColorName {
UIColor *color;
@synchronized(_ColorNameCache) {
// Look for the color in the cache
color = [_ColorNameCache objectForKey:cssColorName];
if ((id)color == [NSNull null]) {
// If it wasn't there previously, it's still not there now
color = nil;
} else if (!color) {
// Color not in cache, so search for it now
color = [self __searchForColorByName:cssColorName];
// Set the value in cache, storing NSNull on failure
[_ColorNameCache setObject:(color ?: (id)[NSNull null])
forKey:cssColorName];
}
}
return color;
}
// Lookup a color using a crayola name
+ (UIColor *)crayonWithName:(NSString *)crayolaColorName {
UIColor *color;
@synchronized(_CrayolaNameCache) {
// Look for the color in the cache
color = [_CrayolaNameCache objectForKey:crayolaColorName];
if ((id)color == [NSNull null]) {
// If it wasn't there previously, it's still not there now
color = nil;
} else if (!color) {
// Color not in cache, so search for it now
color = [self __searchForCrayolaByName:crayolaColorName];
// Set the value in cache, storing NSNull on failure
[_CrayolaNameCache setObject:(color ?: (id)[NSNull null])
forKey:crayolaColorName];
}
}
return color;
}
+ (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;
NSUInteger 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:fmaxf(0.0, fminf(1.0, rgb[0] / 255.0f))
green:fmaxf(0.0, fminf(1.0, rgb[1] / 255.0f))
blue:fmaxf(0.0, fminf(1.0, rgb[2] / 255.0f))
alpha:fmaxf(0.0, fminf(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:fmaxf(0.0, fminf(360.0, hue))
saturation:fmaxf(0.0, fminf(1.0, saturation / 100.0f))
lightness:fmaxf(0.0, fminf(1.0, lightness / 100.0f))
alpha:fmaxf(0.0, fminf(1.0, alpha))];
} else {
// Assume it's a css color name
return [self colorWithName:cssDescription];
}
}
#if __IPHONE_OS_VERSION_MAX_ALLOWED < 50000
+ (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];
}
#endif
+ (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];
}
+ (UIColor *)colorWithByteRGBDictionary:(NSDictionary *)colorDict {
UIColor *color = [UIColor colorWithRed:[[colorDict objectForKey:@"red"] floatValue]/255
green:[[colorDict objectForKey:@"green"] floatValue]/255
blue:[[colorDict objectForKey:@"blue"] floatValue]/255
alpha:[[colorDict objectForKey:@"alpha"] floatValue]/255
];
return color;
}
+ (UIColor *)colorWithNormalizedRGBDictionary:(NSDictionary *)colorDict {
UIColor *color = [UIColor colorWithRed:[[colorDict objectForKey:@"red"] floatValue]
green:[[colorDict objectForKey:@"green"] floatValue]
blue:[[colorDict objectForKey:@"blue"] floatValue]
alpha:[[colorDict objectForKey:@"alpha"] floatValue]
];
return color;
}
+ (UIColor *)colorWithRGBDictionary:(NSDictionary *)colorDict {
UIColor *color = nil;
if (
[[colorDict objectForKey:@"red"] floatValue] <= 1.0 &&
[[colorDict objectForKey:@"blue"] floatValue] <= 1.0 &&
[[colorDict objectForKey:@"green"] floatValue] <= 1.0 &&
[[colorDict objectForKey:@"alpha"] floatValue] <= 1.0
) {
color = [UIColor colorWithNormalizedRGBDictionary:colorDict];
} else {
color = [UIColor colorWithByteRGBDictionary:colorDict];
}
return color;
}
#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 = 0, g = 0, b = 0;
// 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 = (int)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 = fmaxf(r, fmaxf(g, b));
CGFloat min = fminf(r, fminf(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;
}
/*
* 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";
static const char *_CrayolaNameDB = ","
"Almond#EED9C4,Antique Brass#C88A65,Apricot#FDD5B1,Aquamarine#71D9E2,Asparagus#7BA05B,"
"Atomic Tangerine#FF9966,Banana Mania#FBE7B2,Beaver#926F5B,Bittersweet#FE6F5E,Black#000000,"
"Blizzard Blue#A3E3ED,Blue#0066FF,Blue Bell#9999CC,Blue Green#0095B6,Blue Violet#6456B7,"
"Brick Red#C62D42,Brink Pink#FB607F,Brown#AF593E,Burnt Orange#FF7034,Burnt Sienna#E97451,"
"Cadet Blue#A9B2C3,Canary#FFFF99,Caribbean Green#00CC99,Carnation Pink#FFA6C9,Cerise#DA3287,"
"Cerulean#02A4D3,Chartreuse#FF9966,Chestnut#B94E48,Copper#DA8A67,Cornflower#93CCEA,Cotton Candy#FFB7D5,"
"Cranberry#DB5079,Dandelion#FED85D,Denim#1560BD,Desert Sand#EDC9AF,Eggplant#614051,Electric Lime#CCFF00,"
"Fern#63B76C,Flesh#FFCBA4,Forest Green#5FA777,Fuchsia#C154C1,Fuzzy Wuzzy Brown#C45655,Gold#E6BE8A,Goldenrod#FCD667,"
"Granny Smith Apple#9DE093,Gray#8B8680,Green#01A368,Green Yellow#F1E788,Happy Ever After#6CDA37,Hot Magenta#FF00CC,"
"Inch Worm#B0E313,Indian Red#B94E48,Indigo#4F69C6,Jazzberry Jam#A50B5E,Jungle Green#29AB87,Laser Lemon#FFFF66,"
"Lavender#FBAED2,Macaroni And Cheese#FFB97B,Magenta#F653A6,Magic Mint#AAF0D1,Mahogany#CA3435,Manatee#8D90A1,"
"Mango Tango#E77200,Maroon#C32148,Mauvelous#F091A9,Melon#FEBAAD,Midnight Blue#003366,Mountain Meadow#1AB385,"
"Mulberry#C54B8C,Navy Blue#0066CC,Neon Carrot#FF9933,Olive Green#B5B35C,Orange#FF681F,Orchid#E29CD2,Outer Space#2D383A,"
"Outrageous Orange#FF6037,Pacific Blue#009DC4,Peach#FFCBA4,Periwinkle#C3CDE6,Pig Pink#FDD7E4,Pine Green#01796F,"
"Pink Flamingo#FF66FF,Plum#843179,Prussian Blue#003366,Purple Heart#652DC1,Purple Mountain's Majesty#9678B6,"
"Purple Pizzazz#FF00CC,Radical Red#FF355E,Raw Sienna#D27D46,Razzle Dazzle Rose#FF33CC,Razzmatazz#E30B5C,Red#ED0A3F,"
"Red Orange#FF3F34,Red Violet#BB3385,Robin's Egg Blue#00CCCC,Royal Purple#6B3FA0,Salmon#FF91A4,Scarlet#FD0E35,"
"Screamin' Green#66FF66,Sea Green#93DFB8,Sepia#9E5B40,Shadow#837050,Shamrock#33CC99,Shocking Pink#FF6FFF,Silver#C9C0BB,"
"Sky Blue#76D7EA,Spring Green#ECEBBD,Sunglow#FFCC33,Sunset Orange#FE4C40,Tan#FA9D5A,Tickle Me Pink#FC80A5,Timberwolf#D9D6CF,"
"Torch Red#FD0E35,Tropical Rain Forest#00755E,Tumbleweed#DEA681,Turquoise Blue#6CDAE7,Ultra Green#66FF66,Ultra Orange#FF6037,"
"Ultra Pink#FF6FFF,Ultra Red#FD5B78,Ultra Yellow#FFFF66,Unmellow Yellow#FFFF66,Violet (purple)#8359A3,Violet Red#F7468A,"
"Vivid Tangerine#FF9980,Vivid Violet#803790,White#FFFFFF,Wild Blue Yonder#7A89B8,Wild Strawberry#FF3399,Wild Watermelon#FD5B78,"
"Wisteria#C9A0DC,Yellow#FBE870,Yellow Green#C5E17A,Yellow Orange#FFAE42";
+ (UIColor *)__searchForColorByName:(NSString *)cssColorName {
UIColor *result = nil;
// Compile the string we'll use to search against the database
// We search for ",<colorname>#" to avoid false matches
const char *searchString = [[NSString stringWithFormat:@",%@#", cssColorName] UTF8String];
// Search for the color name
const char *found = strstr(_ColorNameDB, searchString);
// If found, step past the search string and grab the hex representation
if (found) {
const char *after = found + strlen(searchString);
int hex;
if (sscanf(after, "%x", &hex) == 1) {
result = [self colorWithRGBHex:hex];
}
}
return result;
}
+ (UIColor *)__searchForCrayolaByName:(NSString *)crayolaColorName {
UIColor *result = nil;
// Compile the string we'll use to search against the database
// We search for ",<colorname>#" to avoid false matches
const char *searchString = [[NSString stringWithFormat:@",%@#", crayolaColorName] UTF8String];
// Search for the color name
const char *found = strstr(_CrayolaNameDB, searchString);
// If found, step past the search string and grab the hex representation
if (found) {
const char *after = found + strlen(searchString);
int hex;
if (sscanf(after, "%x", &hex) == 1) {
result = [self colorWithRGBHex:hex];
}
}
return result;
}
@end
Jump to Line
Something went wrong with that request. Please try again.