- Added GTMLuminance for working with colors in HSL space easily.

- Added GTMTheme for doing product wide theme modifications.

1 files changed, 153 insertions, 0 deletions

diff --git a/AppKit/GTMNSColor+Luminance.m b/AppKit/GTMNSColor+Luminance.m
new file mode 100644
index 0000000..5b10dbe
--- /dev/null
+++ b/AppKit/GTMNSColor+Luminance.m
@@ -0,0 +1,153 @@
+//
+//  GTMNSColor+Luminance.m
+//
+//  Copyright 2009 Google Inc.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not
+//  use this file except in compliance with the License.  You may obtain a copy
+//  of the License at
+// 
+//  http://www.apache.org/licenses/LICENSE-2.0
+// 
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+//  License for the specific language governing permissions and limitations under
+//  the License.
+//
+
+#if MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_5
+
+#import "GTMNSColor+Luminance.h"
+
+static const CGFloat kGTMLuminanceDarkCutoff = 0.6;
+
+@implementation NSColorSpace (GTMNSColorSpaceLuminanceHelpers)
+
+// TODO(alcor): we may want to keep one of these around for performance reasons
++ (NSColorSpace *)gtm_labColorSpace {
+  // Observer= 2°, Illuminant= D65
+  // TODO(alcor): these should come from ColorSync
+  CGFloat whitePoint[3] = {0.95047, 1.0, 1.08883};
+  CGFloat blackPoint[3] = {0, 0, 0};
+  CGFloat range[4] = {-127, 127, -127, 127};
+  CGColorSpaceRef cs = CGColorSpaceCreateLab(whitePoint, blackPoint, range);
+  NSColorSpace *space = nil;
+  if (cs) {
+    space = [[[NSColorSpace alloc] initWithCGColorSpace:cs] autorelease];
+    CGColorSpaceRelease(cs);
+  }
+  return space;
+}
+@end
+
+@implementation NSColor (GTMLuminance)
+
+- (NSColor *)labColor {
+  return [self colorUsingColorSpace:[NSColorSpace gtm_labColorSpace]];    
+}
+
+- (CGFloat)gtm_luminance {
+  CGFloat lab[4];
+  lab[0] = 0.0;
+  [[self labColor] getComponents:lab];
+  return lab[0] / 100.0;
+}
+
+- (NSColor *)gtm_colorByAdjustingLuminance:(CGFloat)luminance
+                                saturation:(CGFloat)saturation {
+  CGFloat lab[4];
+  [[self labColor] getComponents:lab];
+  lab[0] *= 1.0 + luminance;
+  // If luminance is greater than 100, we desaturate it so that we don't get
+  // wild colors coming out of the forumula
+  if (lab[0] > 100) {
+    CGFloat clipping = lab[0] - 100;
+    CGFloat desaturation = (50.0 - clipping) / 50.0;
+    saturation = MIN(saturation, desaturation);
+  } 
+  lab[1] *= saturation;
+  lab[2] *= saturation;
+  return [NSColor colorWithColorSpace:[NSColorSpace gtm_labColorSpace]
+                           components:lab
+                                count:sizeof(lab) / sizeof(lab[0])];
+}
+
+- (NSColor *)gtm_colorByAdjustingLuminance:(CGFloat)luminance {
+  return [self gtm_colorByAdjustingLuminance:luminance saturation:1.0];
+}
+
+// TODO(alcor): these constants are largely made up, come up with a consistent
+// set of values or at least guidelines
+- (NSColor *)gtm_colorAdjustedFor:(GTMColorationUse)use {
+  NSColor *color = nil;
+  switch (use) {
+    case GTMColorationBaseHighlight:
+      color = [self gtm_colorByAdjustingLuminance:0.15];
+      break;
+    case GTMColorationBaseMidtone:
+      color = self;
+      break;
+    case GTMColorationBaseShadow:
+      color = [self gtm_colorByAdjustingLuminance:-0.15];
+      break;
+    case GTMColorationBasePenumbra:
+      color = [self gtm_colorByAdjustingLuminance:-0.10];
+      break;
+    case GTMColorationLightHighlight:
+      color = [self gtm_colorByAdjustingLuminance:0.25];
+      color = [color blendedColorWithFraction:0.9 ofColor:[NSColor whiteColor]];
+      break;
+    case GTMColorationLightMidtone:
+      color = [self blendedColorWithFraction:0.8 ofColor:[NSColor whiteColor]];
+      break;
+    case GTMColorationLightShadow:
+      color = [self blendedColorWithFraction:0.7 ofColor:[NSColor whiteColor]];
+      color = [color gtm_colorByAdjustingLuminance:-0.02];
+      break;
+    case GTMColorationLightPenumbra:
+      color = [self blendedColorWithFraction:0.8 ofColor:[NSColor whiteColor]];
+      color = [color gtm_colorByAdjustingLuminance:-0.01];
+      break;
+    case GTMColorationDarkHighlight:
+      color = [self gtm_colorByAdjustingLuminance:-0.20];
+      break;
+    case GTMColorationDarkMidtone:
+      color = [self gtm_colorByAdjustingLuminance:-0.25];
+      break;
+    case GTMColorationDarkShadow:
+      color = [self gtm_colorByAdjustingLuminance:-0.30 saturation:1.4];
+      break;
+    case GTMColorationDarkPenumbra:
+      color = [self gtm_colorByAdjustingLuminance:-0.25];
+      break;
+    default:
+      _GTMDevLog(@"Invalid Coloration Use %d", use);
+      color = self;
+      break;
+  }
+  return color;
+}
+const CGFloat kDefaultFade = 0.3;
+
+- (NSColor *)gtm_colorAdjustedFor:(GTMColorationUse)use faded:(BOOL)fade {
+  NSColor *color = [self gtm_colorAdjustedFor:use];
+  if (fade) {
+    CGFloat luminance = [color gtm_luminance];
+    color = [color gtm_colorByAdjustingLuminance:
+               kDefaultFade * (1.0 - luminance) 
+                                      saturation:kDefaultFade];
+  }
+  return color;
+}
+
+- (BOOL)gtm_isDarkColor {
+  return [self gtm_luminance] < kGTMLuminanceDarkCutoff;
+}
+
+- (NSColor *)gtm_legibleTextColor {
+  return [self gtm_isDarkColor] ? [NSColor whiteColor] : [NSColor blackColor];
+}
+
+@end
+#endif // MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_5