Constructing an NSColor from Color panel values

Matt Legend Gemmell — Fri, 05 Oct 2007 17:10:08 +0000

I often find myself constructing an NSColor object based on having sampled a color using the standard Color panel. The issue, of course, is that you need to divide the values in the picker by 255 to get the respective red/green/blue components for an RGB NSColor, as those constructors take values in the 0-1 range.

Here’s a trivial category on NSColor to allow you to use the values straight out of the Color panel.

Header:

#import

@interface NSColor (PickerValues)

+ (NSColor *)colorWithCalibratedPickerRed:(float)red green:(float)green
blue:(float)blue alpha:(float)alpha;

@end

Implementation:

#import "NSColor+PickerValues.h"

@implementation NSColor (PickerValues)

+ (NSColor *)colorWithCalibratedPickerRed:(float)red green:(float)green
blue:(float)blue alpha:(float)alpha
{
float maxVal = 255.0;
return [NSColor colorWithCalibratedRed:(red / maxVal)
green:(green / maxVal)
blue:(blue / maxVal)
alpha:alpha];
}

@end

Setting the text color of an NSButton

Matt Legend Gemmell — Thu, 04 Oct 2007 20:56:30 +0000

In this era of white-on-black (HUD) interfaces, we often want to change the text-color of NSButtons (including checkboxes and such). NSTextFieldCell has a -setTextColor: method, but NSButtonCell doesn’t. You can use -setAttributedTitle: to achieve the desired result, but that’s a bit of a hassle.

Here’s a simple little category on NSButton which adds -textColor and -setTextColor: methods to the class.

Header:

#import

@interface NSButton (TextColor)

- (NSColor *)textColor;
- (void)setTextColor:(NSColor *)textColor;

@end

Implementation:

#import "NSButton+TextColor.h"

@implementation NSButton (TextColor)

- (NSColor *)textColor
{
NSAttributedString *attrTitle = [self attributedTitle];
int len = [attrTitle length];
NSRange range = NSMakeRange(0, MIN(len, 1)); // take color from first char
NSDictionary *attrs = [attrTitle fontAttributesInRange:range];
NSColor *textColor = [NSColor controlTextColor];
if (attrs) {
textColor = [attrs objectForKey:NSForegroundColorAttributeName];
}
return textColor;
}

- (void)setTextColor:(NSColor *)textColor
{
NSMutableAttributedString *attrTitle = [[NSMutableAttributedString alloc]
initWithAttributedString:[self attributedTitle]];
int len = [attrTitle length];
NSRange range = NSMakeRange(0, len);
[attrTitle addAttribute:NSForegroundColorAttributeName
value:textColor
range:range];
[attrTitle fixAttributesInRange:range];
[self setAttributedTitle:attrTitle];
[attrTitle release];
}

@end

Paste Buffer

Constructing an NSColor from Color panel values

Setting the text color of an NSButton