[swift4]文字列に合うサイズ領域を求める

calculateRect.swift

// Xcode 9.4
// Swift 4.1

static func calculateRect(text: String) -> CGRect {

    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.lineBreakMode = NSLineBreakMode.byWordWrapping
    let attributeDict = [
        NSAttributedStringKey.font: UIFont.systemFont(ofSize: 14.0),
        NSAttributedStringKey.paragraphStyle: paragraphStyle
    ]
    let constraintsSize = CGSize(width: 250, height: 44)
    return NSString(string: text).boundingRect(with: constraintsSize, options: NSStringDrawingOptions.usesLineFragmentOrigin, attributes: attributeDict, context: nil)
}