Что вызывает искажение обводки контура при анимации вращения устройства? Какие есть способы предотвратить это?
Непосредственно перед запуском анимации контур выглядит так, как будто он был нарисован каллиграфическим пером, а к тому времени, когда вращение завершается, он снова выглядит нормально.
введите описание изображения здесь
Чертеж
class DrawingView: UIView {
override func draw(_ rect: CGRect) {
let strokeW: CGFloat = 10
let center = CGPoint(x: self.bounds.midX, y: self.bounds.midY)
let path = UIBezierPath(ovalIn: self.bounds.insetBy(dx: strokeW/2, dy: strokeW/2))
path.lineWidth = strokeW
path.stroke()
path.move(to: center)
path.addLine(to: CGPoint(x: 0, y: 0))
path.stroke()
}
}
Контроллер просмотра
extension NSLayoutConstraint {
func setPriority(_ priority: UILayoutPriority) -> NSLayoutConstraint {
self.priority = priority
return self
}
}
extension UILayoutPriority {
static var high: UILayoutPriority {
return UILayoutPriority(rawValue: 751)
}
}
class ViewController: UIViewController {
var drawingView = DrawingView()
var safeArea = UILayoutGuide()
var lg = UILayoutGuide()
var wConstraint: NSLayoutConstraint!
var hConstraint: NSLayoutConstraint!
override func loadView() {
super.loadView()
drawingView.backgroundColor = .systemTeal
self.view.addSubview(drawingView)
}
override func viewDidLoad() {
super.viewDidLoad()
self.drawingView.translatesAutoresizingMaskIntoConstraints = false
applyConstraints()
updateOrientation()
}
func updateOrientation() {
if self.view.bounds.width < self.view.bounds.height {
self.wConstraint.constant = 180
self.hConstraint.constant = 320
} else {
self.wConstraint.constant = 320
self.hConstraint.constant = 180
}
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
coordinator.animate(alongsideTransition: {_ in
self.updateOrientation()
self.view.layoutIfNeeded()
self.drawingView.setNeedsDisplay()
})
}
func applyConstraints() {
safeArea = self.view.safeAreaLayoutGuide
self.view.addLayoutGuide(lg)
wConstraint = lg.widthAnchor.constraint(equalToConstant: 180)
hConstraint = lg.heightAnchor.constraint(equalToConstant: 320)
NSLayoutConstraint.activate([wConstraint, hConstraint])
// layout guide constraints
let lgConstraints: [NSLayoutConstraint] = ([
lg.centerXAnchor.constraint(equalTo: safeArea.centerXAnchor),
lg.centerYAnchor.constraint(equalTo: safeArea.centerYAnchor),
lg.leadingAnchor.constraint(greaterThanOrEqualTo: safeArea.leadingAnchor, constant: 10),
lg.trailingAnchor.constraint(lessThanOrEqualTo: safeArea.trailingAnchor, constant: 10),
lg.topAnchor.constraint(greaterThanOrEqualTo: safeArea.topAnchor, constant: 10),
lg.bottomAnchor.constraint(lessThanOrEqualTo: safeArea.bottomAnchor, constant: 10),
lg.leadingAnchor.constraint(equalTo: safeArea.leadingAnchor, constant: 10).setPriority(.high),
lg.trailingAnchor.constraint(equalTo: safeArea.trailingAnchor, constant: 10).setPriority(.high),
lg.topAnchor.constraint(equalTo: safeArea.topAnchor, constant: 10).setPriority(.high),
lg.bottomAnchor.constraint(equalTo: safeArea.bottomAnchor, constant: 10).setPriority(.high),
])
NSLayoutConstraint.activate(lgConstraints)
// drawingView constraints
let drawingViewConstraints: [NSLayoutConstraint] = ([
drawingView.leadingAnchor.constraint(equalTo: lg.leadingAnchor),
drawingView.trailingAnchor.constraint(equalTo: lg.trailingAnchor),
drawingView.topAnchor.constraint(equalTo: lg.topAnchor),
drawingView.bottomAnchor.constraint(equalTo: lg.bottomAnchor)
])
NSLayoutConstraint.activate(drawingViewConstraints)
}
}