Open Radar

 
Summary:
Instead of having Content Size Category Constants (including Accessibility contents and UIApplication's preferredContentSizeCategory) as NSStrings, make them enumerations. This would allow for cleaner/faster code when supporting DynamicType with custom (non system-provided) fonts.

Steps to Reproduce:
Suppose we're using a custom font in an app and we're supporting DynamicType. With a system font, this means we'd set UILabel fonts with UIFont's preferredFontForTextStyle. With a custom font, we have to essentially mimic preferredFontForTextStyle, but return our custom font in the appropriate size. We might make a UIFont category message called preferredCustomFontForTextStyle, whose body looks like:

CGFloat fontSize;
if ([style isEqualToString:UIFontTextStyleHeadline]) {
		if ([preferredContentSizeCategory isEqualToString:UIContentSizeCategoryExtraSmall])
			fontSize = 12.0;
		else if ([preferredContentSizeCategory isEqualToString:UIContentSizeCategorySmall])
			fontSize = 14.0;
		else if ([preferredContentSizeCategory isEqualToString:UIContentSizeCategoryMedium])
			fontSize = 16.0;
		else if ([preferredContentSizeCategory isEqualToString:UIContentSizeCategoryLarge])
			fontSize = 18.0;
		else if ([preferredContentSizeCategory isEqualToString:UIContentSizeCategoryExtraLarge])
			fontSize = 20.0;
		else if ([preferredContentSizeCategory isEqualToString:UIContentSizeCategoryExtraExtraLarge])
			fontSize = 22.0;
		else if ([preferredContentSizeCategory isEqualToString:UIContentSizeCategoryExtraExtraExtraLarge])
			fontSize = 24.0;
...

return ([UIFont fontWithName:@"customFont" size:fontSize]);

We need to repeat this for each and every Content Size Category, Accessibility Content Size Category, and Text Style. In the worst case, we have to enumerate and isEqualToString every single constant. If the constants were enumerable, the code would still be a little bit ugly, but it would run much faster.

CGFloat fontSize;
switch (textStyle) {
case UIFontTextStyleHeadline:
        switch (preferredContentSizeCategory) {
        case UIContentSizeCategoryLarge:
                fontSize = 18.0;
                break;
        ...
        default:
                fontSize = 12.0;
                break;
        }
case ...
        ....
}
return ([UIFont fontWithName:@"customFont" size:18.0]);

Expected Results:
Faster slightly-less-ugly-but-still-big code.

Actual Results:
Slow ugly code.