UIColor+uiGradients.m.erb

#import "UIColor+uiGradients.h"

@implementation UIColor (uiGradients)<% @colors.each do |color| %>

# pragma mark - <%= color["name"]%>

+ (UIColor *)uig_<%= color["camelized_name"]%>StartColor {
    return [UIColor uig_colorWithHexString:@"<%= color["start_color_hex"]%>"];
}

+ (UIColor *)uig_<%= color["camelized_name"]%>EndColor {
    return [UIColor uig_colorWithHexString:@"<%= color["end_color_hex"]%>"];
}<% end %>

# pragma mark - Helpers

+ (CGFloat)uig_colorComponentFrom:(NSString *)string start:(NSUInteger)start length:(NSUInteger)length {
    NSString *substring = [string substringWithRange: NSMakeRange(start, length)];
    NSString *fullHex = length == 2 ? substring : [NSString stringWithFormat: @"%@%@", substring, substring];
    unsigned hexComponent;
    [[NSScanner scannerWithString: fullHex] scanHexInt: &hexComponent];
    return hexComponent / 255.0;
}

+ (UIColor *)uig_colorWithHexString:(NSString *)hexString {
    NSString *colorString = [[hexString stringByReplacingOccurrencesOfString: @"#" withString: @""] uppercaseString];
    CGFloat alpha, red, blue, green;
    switch ([colorString length]) {
        case 3: // #RGB
            alpha = 1.0f;
            red   = [self uig_colorComponentFrom: colorString start: 0 length: 1];
            green = [self uig_colorComponentFrom: colorString start: 1 length: 1];
            blue  = [self uig_colorComponentFrom: colorString start: 2 length: 1];
            break;
        case 4: // #ARGB
            alpha = [self uig_colorComponentFrom: colorString start: 0 length: 1];
            red   = [self uig_colorComponentFrom: colorString start: 1 length: 1];
            green = [self uig_colorComponentFrom: colorString start: 2 length: 1];
            blue  = [self uig_colorComponentFrom: colorString start: 3 length: 1];
            break;
        case 6: // #RRGGBB
            alpha = 1.0f;
            red   = [self uig_colorComponentFrom: colorString start: 0 length: 2];
            green = [self uig_colorComponentFrom: colorString start: 2 length: 2];
            blue  = [self uig_colorComponentFrom: colorString start: 4 length: 2];
            break;
        case 8: // #AARRGGBB
            alpha = [self uig_colorComponentFrom: colorString start: 0 length: 2];
            red   = [self uig_colorComponentFrom: colorString start: 2 length: 2];
            green = [self uig_colorComponentFrom: colorString start: 4 length: 2];
            blue  = [self uig_colorComponentFrom: colorString start: 6 length: 2];
            break;
        default:
            return nil;
    }
    return [UIColor colorWithRed: red green: green blue: blue alpha: alpha];
}

@end