PLToggleControl

PLToggleControl.swift

@IBDesignable class PLToggleControl: UIControl {

    var items = [String]()
    var labels = [UILabel]()
    var activeLineView = UIView()
    
    @IBInsepctable var activeTextColor: UIColor = .whiteColor()
    @IBInspectable var inactiveTextColor: UIColor = .grayColor()
    @IBInspectable var buttonColor: UIColor = .blackColor()
    @IBInspectable var activeLineColor: UIColor = .blackColor()

    var selectedIndex = 0 {
        didSet {
            displaySelectedIndex()
        }
    }

    override init(frame: CGRect) {
        super.init(frame: frame)

        setupControl()

    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        
        setupControl()
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        let labelHeight = bounds.height
        let labelWidth = bounds.width / CGFloat(labels.count)

        labels.forEach { label in
            let xPosition = CGFloat(labels.indexOf(label)!) * labelWidth
            label.frame = CGRect(x: xPosition, y: 0, width: labelWidth, height: labelHeight)
        }
        setupActiveLine()
        displaySelectedIndex()
    }

    override func beginTrackingWithTouch(touch: UITouch, withEvent event: UIEvent?) -> Bool {
        let location = touch.locationInView(self)

        for (i, label) in labels.enumerate() {
            if label.frame.contains(location) {
                selectedIndex = i
            }
        }

        sendActionsForControlEvents(.ValueChanged)

        return true
    }


    private func setupControl() {
        backgroundColor = buttonColor

        setupLabels()
    }

    private func setupLabels() {
        labels.forEach { $0.removeFromSuperview() }
        labels.removeAll(keepCapacity: true)

        items.forEach { item in
            let label = UILabel()
            label.text = item
            label.textAlignment = .Center
            label.textColor = inactiveTextColor
            label.font = UIFont.systemFontOfSize(15)
            addSubview(label)
            labels.append(label)
        }
    }

    private func setupActiveLine() {
        activeLineView.backgroundColor = activeLineColor
        let yPosition = bounds.height - 1.5
        let width = bounds.width / CGFloat(labels.count)
        activeLineView.frame = CGRect(x: 0, y: yPosition, width: width, height: 1.5)
        addSubview(activeLineView)
    }

    private func displaySelectedIndex() {
        labels.forEach { $0.textColor = inactiveTextColor }

        let label = labels[selectedIndex]

        label.textColor = activeTextColor

        let newXOrigin = label.frame.origin.x

        UIView.animateWithDuration(0.2) {
            self.activeLineView.frame.origin.x = newXOrigin
        }
    }
}