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I have a iPhone application with a few custom-defined colors for my theme. Since these colors will be fixed for my UI, I would like to define the colors in a class to be included (Constants.h and Constants.m). How do I do that? (Simply defining them does not work because UIColors are mutable, and would cause errors - Initalizer not constant).
/* Constants.h */ extern UIColor *test; /* Constants.m */ UIColor *test = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0]; Thanks!
922
CGColor is the fundamental data type used internally by Core Graphics to represent colors. CGColor objects, and the functions that operate on them, provide a fast and convenient way of managing and setting colors directly, especially colors that are reused (such as black for text).
alpha. The opacity value of the new color object, specified as a value from 0.0 to 1.0.
Suggested approach: In the old days values outside of 0 and 1 would be clamped (i.e., forced to 0 or 1) because they didn't mean anything, but wide color support means that is no longer the case – a red value beyond 1.0 is especially red, going into the Display P3 gamut.
Creating a custom UIColor Object This can be done in swift by instantiating a custom UIColor object with an initializer. These are some available initializers, init(white: CGFloat, alpha: CGFloat) init(hue: CGFloat, saturation: CGFloat, brightness: CGFloat, alpha: CGFloat)
A UIColor is not mutable. I usually do this with colors, fonts and images. You could easily modify it to use singletons or have a static initializer.
@interface UIColor (MyProject) +(UIColor *) colorForSomePurpose; @end @implementation UIColor (MyProject) +(UIColor *) colorForSomePurpose { return [UIColor colorWithRed:0.6 green:0.8 blue:1.0 alpha:1.0]; } @end If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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