How do I create a bold UIFont from a regular UIFont?

Question

If I have a UIFont object, is it possible to convert it to bold? I don't know the font name, I just have a UIFont object. What I want is a function like

UIFont *boldFontFromFont(UIFont *input)
{
    return [input derivedFontWithFontWeight:UIFontWeightBold];
}

How can I change the code so that it works. (The code above does not work, I just made it up to illustrate the point.)

Thanks in advance.

Answer 1

To get a bold font you need to pass a specific name of the font from a font family. You can get a font family name from a given font, then list all fonts from this family. In general, a bold font will contain "bold" in its name, but the format isn't strict and there could be variations like "Helvetica-BoldOblique", for example. You can start from this code:

- (UIFont *)boldFontFromFont:(UIFont *)font
{
    NSString *familyName = [font familyName];
    NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName];
    for (NSString *fontName in fontNames)
    {
        if ([fontName rangeOfString:@"bold" options:NSCaseInsensitiveSearch].location != NSNotFound)
        {
            UIFont *boldFont = [UIFont fontWithName:fontName size:font.pointSize];
            return boldFont;
        }
    }
    return nil;
}