Custom UITableViewCell labels - ios

Question

I'm trying to create a custom UITableViewCell with 3 labels, in a similar style to the subtitle style, but with a label on the right, too. I've got 2 issues, so far:
When creating the labels on the left, I was using a constant 16 offset, but have since found this is incorrect. The separator inset returns 15 (self.separatorInset.left), but iPad the labels seem to be 22.5 from the left. I'll have to do this in code, but is checking for the iPad UI idiom and multiplying by 1.5 the correct way of doing this?
The second issue is that I am using dynamic font sizes: Body for the main label and Caption 1 for the subtitle. However, this creates labels with font size 17 and 12 respectively, while the system cell's labels are 16 and 11. I've got a custom UILabel that tries to ensure system font size changes are respected. Should I make the font size 1 smaller in this class?
class DynamicFontLabel: UILabel {
var fontStyle: String?
convenience override init() {
self.init(fontStyle: UIFontTextStyleBody)
}
init(fontStyle: String) {
super.init()
self.font = UIFont.preferredFontForTextStyle(fontStyle)
self.setup()
}
override init(frame: CGRect) {
super.init(frame: frame)
self.setup()
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
self.setup()
}
func setup() {
// Ensure the text color is correct, as per the UILabel appearance
self.textColor = UILabel.appearance().textColor
self.fontStyle = self.currentFontStyle()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "updateFontSize", name: UIContentSizeCategoryDidChangeNotification, object: nil)
self.numberOfLines = 0
self.lineBreakMode = NSLineBreakMode.ByWordWrapping
}
func currentFontStyle() -> String {
if self.font.isEqual(UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)) {
return UIFontTextStyleHeadline
} else if self.font.isEqual(UIFont.preferredFontForTextStyle(UIFontTextStyleBody)) {
return UIFontTextStyleBody
} else if self.font.isEqual(UIFont.preferredFontForTextStyle(UIFontTextStyleCaption1)) {
return UIFontTextStyleCaption1
} else if self.font.isEqual(UIFont.preferredFontForTextStyle(UIFontTextStyleCaption2)) {
return UIFontTextStyleCaption2
} else if self.font.isEqual(UIFont.preferredFontForTextStyle(UIFontTextStyleFootnote)) {
return UIFontTextStyleFootnote
} else if self.font.isEqual(UIFont.preferredFontForTextStyle(UIFontTextStyleSubheadline)) {
return UIFontTextStyleSubheadline
}
return UIFontTextStyleBody
}
func updateFontSize() {
if let fontStyle = self.fontStyle {
self.font = UIFont.preferredFontForTextStyle(fontStyle)
}
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
}