Swift 滚动label

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/// 滚动label
class USTradeScrollLabelView: USBaseView {
fileprivate let scrollLabel: UILabel = UILabel()
var scrollText: String = ""

fileprivate var rectMark1: CGRect = CGRect.zero
fileprivate var rectMark2: CGRect = CGRect.zero

fileprivate var arrLabel: [UILabel] = []
var timeInterval: TimeInterval = 0.0
var isStop: Bool = false

init(info: String, frame: CGRect) {
    super.init(frame: frame)

// self.scrollText = info
self.scrollText = info
self.setupUI()
}

required public init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

func setupUI() {

// super.setup()

    self.scrollText = "   \(self.scrollText)   "
    self.timeInterval = self.displayDurationForString(self.scrollText)
    self.clipsToBounds = true
    
    self.scrollLabel.us.customize { (view) in
        view.text = self.scrollText
        view.font = USFont.t05.font
        view.us.handleTheme {
            view.textColor = USColor.c301.color
        }
    }
    
    let sizeOfText = self.scrollLabel.sizeThatFits(CGSize.zero)
    self.rectMark1 = CGRect(x: 0, y: 0, width: sizeOfText.width, height: self.bounds.size.height)
    self.rectMark2 = CGRect(x: self.rectMark1.origin.x + self.rectMark1.size.width, y: 0, width: sizeOfText.width, height: self.bounds.size.height)
    
    self.scrollLabel.frame = self.rectMark1
    self.addSubview(self.scrollLabel)
    
    self.arrLabel.append(self.scrollLabel)
    
    let useReserve = sizeOfText.width > self.frame.size.width ? true: false
    
    if useReserve {
        let reserveTextLabel = UILabel(frame: self.rectMark2)
        reserveTextLabel.us.customize({ (view) in
            view.text = self.scrollText
            view.font = USFont.t05.font
            view.us.handleTheme {
                view.textColor = USColor.c301.color
            }
            self.addSubview(view)
            self.arrLabel.append(reserveTextLabel)
            // label滚动
            self.scrollLabelIfNeeded()
        })
        
    }
    
}

fileprivate func scrollLabelIfNeeded() {
    if !self.isStop {
        let label1 = self.arrLabel[0]
        let label2 = self.arrLabel[1]
        
        UIView.transition(with: self, duration: self.timeInterval, options: [.curveLinear], animations: {
            label1.frame = CGRect(x: -self.rectMark1.size.width, y: 0, width: self.rectMark1.size.width, height: self.rectMark1.size.height)
            label2.frame = CGRect(x: label1.frame.origin.x + label1.frame.size.width, y: 0, width: label1.frame.size.width, height: label1.frame.size.height)
            
        }, completion: { [weak self](finished) in
            guard let `self` = self else {
                return
            }
            label1.frame = self.rectMark2
            label2.frame = self.rectMark1
            
            self.arrLabel[0] = label2
            self.arrLabel[1] = label1
            
            self.scrollLabelIfNeeded()
        })
    }
}

fileprivate func displayDurationForString(_ string: String) -> TimeInterval {
    let inter: TimeInterval = Double(string.characters.count / 3)
    return inter
}

func start() {
    self.isStop = false
    let label1 = self.arrLabel[0]
    let label2 = self.arrLabel[1]
    label1.frame = self.rectMark2
    label2.frame = self.rectMark1
    
    self.arrLabel[0] = label2
    self.arrLabel[1] = label1
    
    self.scrollLabelIfNeeded()
}

func stop() {
    self.isStop = true
}

}

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