// UIStackView using .fillProportionally

class ProportionalStackVC: UIViewController {
	
	let proLeft: UILabel = {
		let v = UILabel()
		v.textAlignment = .left
		v.lineBreakMode = .byTruncatingTail
		v.backgroundColor = .cyan
		return v
	}()

	let proRight: UILabel = {
		let v = UILabel()
		v.textAlignment = .right
		v.lineBreakMode = .byTruncatingHead
		v.backgroundColor = .yellow
		return v
	}()

	let sampleStrings: [[String]] = [
		["My text is less than half.", "Less than half."],
		["Less than half.", "My text is less than half."],
		["This text is a bit wider than half.", "Less than half."],
		["Less than half.", "This text is a bit wider than half."],
		["This text is considerably wider than half.", "Less than half."],
		["Less than half.", "This text is considerably wider than half."],
		["This text is considerably wider than half.", "Text still Less than half."],
		["Text still Less than half.", "This text is considerably wider than half."],
		["The Left Label is considerably wider than half.", "Right Label is wider than half."],
		["Left Label is wider than half.", "The Right Label is considerably wider than half."],
		["This text is just about but not quite full width.", "Short."],
		["Short.", "This text is just about but not quite full width."],
	]

	var idx: Int = 0
	
	override func viewDidLoad() {
		super.viewDidLoad()
		
		let stackView = UIStackView()
		stackView.distribution = .fillProportionally
		stackView.spacing = 10
		
		stackView.addArrangedSubview(proLeft)
		stackView.addArrangedSubview(proRight)

		stackView.translatesAutoresizingMaskIntoConstraints = false
		view.addSubview(stackView)
		
		let g = view.safeAreaLayoutGuide
		NSLayoutConstraint.activate([
			stackView.topAnchor.constraint(equalTo: g.topAnchor, constant: 40.0),
			stackView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 8.0),
			stackView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -8.0),
		])
		
		updateLabels()
	}
	
	override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
		updateLabels()
	}

	func updateLabels() {
		
		let p = sampleStrings[idx % sampleStrings.count]
		
		proLeft.text = p[0]
		proRight.text = p[1]

		idx += 1
		if idx == sampleStrings.count {
			idx = 0
		}
		
	}
	
}