UITabBar by default draws a subtle gradient:
I would like to replicate this look and feel in my code with any given tintColor. Just to make it clear: I do not want to set a tintColor on UITabBar (which is possible since iOS 5), I would like to draw the gradient in my own UIView.
I know how to draw the gradient, my problem is how to derive the colors for the gradient from the tintColor. I was thinking about getting the brightness of the color and generating the other colors with different brightness-settings, but that doesn't seem to work that well and looks not as good as I would like it to look.
I need the code for my open source TabBarController: https://github.com/NOUSguide/NGTabBarController
Here's my current code for creating the gradient:
UIColor *baseColor = self.tintColor;
CGFloat hue, saturation, brightness, alpha;
// TODO: Only works on iOS 5
[baseColor getHue:&hue saturation:&saturation brightness:&brightness alpha:&alpha];
// That's the question, how to compute the colors ...
NSArray *colors = [NSArray arrayWithObjects:
[UIColor colorWithHue:hue saturation:saturation brightness:brightness+0.2 alpha:alpha],
[UIColor colorWithHue:hue saturation:saturation brightness:brightness+0.15 alpha:alpha],
[UIColor colorWithHue:hue saturation:saturation brightness:brightness+0.1 alpha:alpha],
baseColor, nil];
NSUInteger colorsCount = colors.count;
CGColorSpaceRef colorSpace = CGColorGetColorSpace([[colors objectAtIndex:0] CGColor]);
NSArray *locations = [NSArray arrayWithObjects:[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:0.25],
[NSNumber numberWithFloat:0.49],
[NSNumber numberWithFloat:0.5], nil];
CGFloat *gradientLocations = NULL;
NSUInteger locationsCount = locations.count;
gradientLocations = (CGFloat *)malloc(sizeof(CGFloat) * locationsCount);
for (NSUInteger i = 0; i < locationsCount; i++) {
gradientLocations[i] = [[locations objectAtIndex:i] floatValue];
}
NSMutableArray *gradientColors = [[NSMutableArray alloc] initWithCapacity:colorsCount];
[colors enumerateObjectsUsingBlock:^(id object, NSUInteger index, BOOL *stop) {
[gradientColors addObject:(id)[(UIColor *)object CGColor]];
}];
_gradientRef = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)gradientColors, gradientLocations);
if (gradientLocations) {
free(gradientLocations);
}
