Vertical UISegmentedControl

UISegmentedControl+Vertical.swift

//
//  UISegmentedControl+Vertical.swift
//  Make a UISegmentedControl vertical by setting mySegmentedControl.vertical = true
//
//  Created by Yonat Sharon on 14/9/14.
//  Copyright (c) 2014 Yonat Sharon. All rights reserved.
//

import UIKit

extension UISegmentedControl {

    /// Present segments one below the other vertically.
    /// Be sure to re-set after inserting segments.
    var vertical : Bool {
        get {
            return fabs(transform.b) > 0.001
        }
        set {
            // rotate view
            self.transform = newValue ? CGAffineTransformMakeRotation(CGFloat(M_PI_2)) : CGAffineTransformIdentity

            let padding : CGFloat = 8
            let maxSize = CGSize(width: CGFloat.max, height: CGFloat.max)
            var size : CGSize
            var maxHeight : CGFloat = 0
            var totalWidth : CGFloat = 0

            // reverse rotate segment content
            for segment in subviews {
                for contentView in segment.subviews {
                    size = contentView.sizeThatFits(maxSize)
                    maxHeight = max(maxHeight, newValue ? size.width : size.height)
                    totalWidth += (newValue ? size.height : size.width) + padding
                    contentView.transform = newValue ? CGAffineTransformMakeRotation(-CGFloat(M_PI_2)) : CGAffineTransformIdentity
                }
            }

            // adjust size
            bounds = CGRect(x: 0, y: 0, width: totalWidth + padding, height: maxHeight + 2*padding)
        }
    }

    func scaleToFit(size: CGSize) { // keeps aspect ratio
        var frameSize = bounds.size
        if vertical { swap(&frameSize.width, &frameSize.height) }
        let scale = min(size.width / frameSize.width, size.height / frameSize.height)
        if scale < 1 {
            transform = CGAffineTransformScale(transform, scale, scale)
        }
    }
}