Detect whether a font is bold/italic on iOS?

Question

Given a UIFont or a CTFont, how can I tell whether the font is bold/italic?

Answer 1

iOS7 Font Descriptor

No reason to use Core Text, you can simply ask UIFont for the fontDescriptor.

        UIFont *font = [UIFont boldSystemFontOfSize:17.0f];
        UIFontDescriptor *fontDescriptor = font.fontDescriptor;
        UIFontDescriptorSymbolicTraits fontDescriptorSymbolicTraits = fontDescriptor.symbolicTraits;
        BOOL isBold = (fontDescriptorSymbolicTraits & UIFontDescriptorTraitBold) != 0;

Going forward this is probably the easiest way to ask about the traits of a font.

Answer 2

If you want to do this with Swift 2.0:

extension UIFont {
    var isBold: Bool {
        return fontDescriptor().symbolicTraits.contains(.TraitBold)
    }

    var isItalic: Bool {
        return fontDescriptor().symbolicTraits.contains(.TraitItalic)
    }
}

Usage:

let font: UIFont = UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)
if font.isBold {
  print("it's bold..")
}