UITextView Height Calculation

UITextView+HeightCalculation.swift

extension UITextView {
    // Note: This will trigger a text rendering!
    func calculateViewHeightWithCurrentWidth() -> CGFloat {
        let textWidth = self.frame.width -
            self.textContainerInset.left -
            self.textContainerInset.right -
            self.textContainer.lineFragmentPadding * 2.0 -
            self.contentInset.left -
            self.contentInset.right
        
        let maxSize = CGSize(width: textWidth, height: CGFloat.max)
        var calculatedSize = self.attributedText.boundingRectWithSize(maxSize,
                                                                      options: [.UsesLineFragmentOrigin, .UsesFontLeading],
                                                                      context: nil).size
        calculatedSize.height += self.textContainerInset.top
        calculatedSize.height += self.textContainerInset.bottom
        
        return ceil(calculatedSize.height)
    }
}