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How do I define constant values of UIColor?

I want to do something like this, but I cannot get a cooperative syntax.

static const UIColor *colorNavbar = [UIColor colorWithRed: 197.0/255.0 green: 169.0/255.0 blue: 140.0/255.0 alpha: 1.0]; 

I suppose that I could define macros, but they are ugly.

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mobibob Avatar asked Apr 27 '10 03:04

mobibob


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1 Answers

I like to use categories to extend classes with new methods for this sort of thing. Here's an excerpt of code I just wrote today:

@implementation UIColor (Extensions)  + (UIColor *)colorWithHueDegrees:(CGFloat)hue saturation:(CGFloat)saturation brightness:(CGFloat)brightness {     return [UIColor colorWithHue:(hue/360) saturation:saturation brightness:brightness alpha:1.0]; }  + (UIColor *)aquaColor {     return [UIColor colorWithHueDegrees:210 saturation:1.0 brightness:1.0]; }  + (UIColor *)paleYellowColor {     return [UIColor colorWithHueDegrees:60 saturation:0.2 brightness:1.0]; }  @end 

Now in code I can do things like:

self.view.backgroundColor = highlight? [UIColor paleYellowColor] : [UIColor whitecolor]; 

and my own defined colors fit right in alongside the system-defined ones.

(Incidentally, I am starting to think more in terms of HSB than RGB as I pay more attention to colors.)

UPDATE regarding precomputing the value: My hunch is that it's not worth it. But if you really wanted, you could memoize the values with static variables:

+ (UIColor *)paleYellowColor {     static UIColor *color = nil;     if (!color) color = [UIColor colorWithHueDegrees:60 saturation:0.2 brightness:1.0];     return color; } 

You could make a macro do do the memoizing, too.

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jasoncrawford Avatar answered Oct 09 '22 18:10

jasoncrawford