I have this working code:
NSMutableArray *shadowColors = [NSMutableArray arrayWithCapacity:2];
color = [UIColor colorWithRed:0 green:0 blue:0 alpha:1]; // Declaration using components
[shadowColors addObject:(id)[color CGColor]];
color = [UIColor colorWithRed:1 green:1 blue:1 alpha:0.0]; // Declaration using components
[shadowColors addObject:(id)[color CGColor]];
CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();
CGGradientRef gradient = CGGradientCreateWithColors(space, (CFArrayRef)shadowColors, NULL);
CGColorSpaceRelease(space);
CGFloat sw = 10.0; // shadow width
CGPoint top1 = CGPointMake(x, y+width/2.0);
CGPoint top2 = CGPointMake(x + sw, y+width/2.0);
CGPoint side1 = CGPointMake(x+width/2.0, y);
CGPoint side2 = CGPointMake(x+width/2.0, y+sw);
CGContextDrawLinearGradient(c, gradient, top1, top2, 0);
CGContextDrawLinearGradient(c, gradient, side1, side2, 0);
CGGradientRelease(gradient);
The color declarations are the part I'm interested in, lines 2 and 4. When I declare them as shown, they work just fine, but if I replace those two lines with the equivalent (I thought, at least) [UIColor blackColor] and [UIColor clearColor] then my gradients disappear. The colors I use don't make any difference, I can use greenColor and redColor and they still don't work.
Am I missing something or is this a bug in Apple's frameworks?
The code that doesn't work. And this is just the first section, everything else is the same.
NSMutableArray *shadowColors = [NSMutableArray arrayWithCapacity:2];
color = [UIColor blackColor];
[shadowColors addObject:(id)[color CGColor]];
color = [UIColor clearColor];
[shadowColors addObject:(id)[color CGColor]];