// Using a UITableViewController

class SecHeadTVC: UITableViewController {
	
	override func viewDidLoad() {
		super.viewDidLoad()
		
		self.title = "Section Header TableViewController"

		tableView.register(UITableViewCell.self, forCellReuseIdentifier: "c")
		
		if #available(iOS 15.0, *) {
			tableView.sectionHeaderTopPadding = 0.0
		}
		
	}

	override func numberOfSections(in tableView: UITableView) -> Int {
		return 5
	}
	override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
		return section + 1
	}
	override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
		let c = tableView.dequeueReusableCell(withIdentifier: "c", for: indexPath)
		c.textLabel?.text = "\(indexPath)"
		c.textLabel?.backgroundColor = .cyan
		c.contentView.backgroundColor = .yellow
		return c
	}
	
	override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
		let v = UILabel()
		v.text = "Header for section: \(section)"
		v.backgroundColor = .green
		return v
	}
}

// Using a UITableView as a Subview of a UIViewController

class SecHeadVC: UIViewController, UITableViewDataSource, UITableViewDelegate {
	
	override func viewDidLoad() {
		super.viewDidLoad()

		self.title = "Section Header TableView as Subview"
		view.backgroundColor = .systemYellow
		
		let tv = UITableView()
		tv.translatesAutoresizingMaskIntoConstraints = false
		view.addSubview(tv)
		
		let g = view.safeAreaLayoutGuide
		
		NSLayoutConstraint.activate([
			
			tv.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
			tv.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
			tv.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
			tv.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),
			
		])

		tv.register(UITableViewCell.self, forCellReuseIdentifier: "c")
		tv.dataSource = self
		tv.delegate = self
		
		if #available(iOS 15.0, *) {
			tv.sectionHeaderTopPadding = 0.0
		}
		
	}
	
	func numberOfSections(in tableView: UITableView) -> Int {
		return 5
	}
	func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
		return section + 1
	}
	func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
		let c = tableView.dequeueReusableCell(withIdentifier: "c", for: indexPath)
		c.textLabel?.text = "\(indexPath)"
		c.textLabel?.backgroundColor = .cyan
		c.contentView.backgroundColor = .yellow
		return c
	}
	
	func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
		let v = UILabel()
		v.text = "Header for section: \(section)"
		v.backgroundColor = .green
		return v
	}
}