Check out example codes for "button sizetofit not working swift". It will help you in understanding the concepts better.

Code Example 1

class ResizableButton: UIButton {
    override var intrinsicContentSize: CGSize {
       let imageViewWidth = imageView?.frame.width ?? 0.0
       let labelSize = titleLabel?.sizeThatFits(CGSize(width: frame.width, height: .greatestFiniteMagnitude)) ?? .zero
       let desiredButtonSize = CGSize(width: labelSize.width + titleEdgeInsets.left + titleEdgeInsets.right + imageViewWidth, height: labelSize.height + titleEdgeInsets.top + titleEdgeInsets.bottom)

       return desiredButtonSize
    }
}

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