uikit - How do I get auto-adjusted font size in iOS 7.0 or later?

Question

I want to get the font size of some text after it's been scaled down in a UILabel or UITextField. This was possible before iOS 7.0: How to get UILabel (UITextView) auto adjusted font size?. However, sizeWithFont has been deprecated in iOS 7.0. I've tried using its replacement, sizeWithAttributes, but with no success. Is there any way to do this in iOS 7.0?

Answer 1

Here's a function I made to get the adjusted font size of a UILabel:

Swift

func getApproximateAdjustedFontSizeWithLabel(label: UILabel) -> CGFloat {

    if label.adjustsFontSizeToFitWidth == true {

        var currentFont: UIFont = label.font
        let originalFontSize = currentFont.pointSize
        var currentSize: CGSize = (label.text! as NSString).sizeWithAttributes([NSFontAttributeName: currentFont])

        while currentSize.width > label.frame.size.width && currentFont.pointSize > (originalFontSize * label.minimumScaleFactor) {
            currentFont = currentFont.fontWithSize(currentFont.pointSize - 1)
            currentSize = (label.text! as NSString).sizeWithAttributes([NSFontAttributeName: currentFont])
        }

        return currentFont.pointSize

    }
    else {

        return label.font.pointSize

    }

}

Objective-C

- (CGFloat)getApproximateAdjustedFontSizeWithLabel:(UILabel *)label {

    if (label.adjustsFontSizeToFitWidth) {

        UIFont *currentFont = label.font;
        CGFloat originalFontSize = currentFont.pointSize;
        CGSize currentSize = [label.text sizeWithAttributes:@{NSFontAttributeName : currentFont}];

        while (currentSize.width > label.frame.size.width && currentFont.pointSize > (originalFontSize * label.minimumScaleFactor)) {
            currentFont = [currentFont fontWithSize:currentFont.pointSize - 1];
            currentSize = [label.text sizeWithAttributes:@{NSFontAttributeName : currentFont}];
        }

        return currentFont.pointSize;
    }
    else {

        return label.font.pointSize;
    }
}