Thin lines

LineView.swift

import UIKit

class LineView: UIView {
	override func sizeThatFits(size: CGSize) -> CGSize {
		return CGSize(width: size.width, height: intrinsicContentSize().height)
	}

	override func intrinsicContentSize() -> CGSize {
		return CGSize(width: UIViewNoIntrinsicMetric, height: 1 / max(1, traitCollection.displayScale))
	}

	override func traitCollectionDidChange(previousTraitCollection: UITraitCollection?) {
		super.traitCollectionDidChange(previousTraitCollection)
		invalidateIntrinsicContentSize()
	}
}