Building User Interfaces with UIKit

class CustomView: UIView {
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupView()
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setupView()
    }

    private func setupView() {
        backgroundColor = UIColor.systemBlue
        layer.cornerRadius = 8
    }
}

let button = UIButton(type: .system)
button.setTitle("Tap Me", for: .normal)
button.backgroundColor = UIColor.systemGreen
button.layer.cornerRadius = 8

view.addSubview(button)
button.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
    button.centerXAnchor.constraint(equalTo: view.centerXAnchor),
    button.centerYAnchor.constraint(equalTo: view.centerYAnchor),
    button.widthAnchor.constraint(equalToConstant: 100),
    button.heightAnchor.constraint(equalToConstant: 40)
])

let view = UIView(frame: CGRect(x: 10, y: 10, width: 100, height: 100))
view.backgroundColor = UIColor.red
print("Frame: " + view.frame.description)
print("Bounds: " + view.bounds.description)

let label = UILabel()
label.text = "Hello, World!"
label.font = UIFont.systemFont(ofSize: 17)
label.textColor = UIColor.black
label.textAlignment = .center
label.numberOfLines = 0

class ViewController: UIViewController {
    @IBOutlet weak var statusLabel: UILabel!
    
    func updateStatus(_ message: String) {
        statusLabel.text = message
        // Optionally animate the change
        UIView.animate(withDuration: 0.3) {
            self.statusLabel.alpha = 1.0
        }
    }
}

let button = UIButton(type: .system)
button.setTitle("Tap Me", for: .normal)
button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)

@objc func buttonTapped() {
    print("Button was tapped!")
}

let button = UIButton(type: .system)
button.setTitle("Submit", for: .normal)
button.setTitleColor(.white, for: .normal)
button.setBackgroundColor(.blue, for: .normal)
button.layer.cornerRadius = 8

extension UIButton {
    func setBackgroundColor(_ color: UIColor, for state: UIControl.State) {
        let background = CALayer()
        background.backgroundColor = color.cgColor
        background.frame = bounds
        layer.insertSublayer(background, at: 0)
    }
}

let imageView = UIImageView()
imageView.image = UIImage(named: "sampleImage")
imageView.contentMode = .scaleAspectFit

let imageView = UIImageView()
imageView.image = UIImage(named: "normalImage")
imageView.highlightedImage = UIImage(named: "highlightedImage")
imageView.isHighlighted = true

let textField = UITextField()
textField.placeholder = "Enter your name"
textField.borderStyle = .roundedRect
textField.text = "John Doe"

textField.addTarget(self, action: #selector(textDidChange), for: .editingChanged)

@objc func textDidChange(_ textField: UITextField) {
    print("Text changed to: \(textField.text ?? "")")
}

let textView = UITextView()
textView.text = "This is a multiline text view."
textView.font = UIFont.systemFont(ofSize: 16)
textView.textColor = .black
textView.backgroundColor = .white
textView.isEditable = true
textView.isScrollEnabled = true

let textView = UITextView()
textView.text = "Select this text to see selection behavior."
textView.isEditable = false // Prevent editing
textView.isSelectable = true // Allow selection

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let scrollView = UIScrollView()
        scrollView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(scrollView)
        
        NSLayoutConstraint.activate([
            scrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            scrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            scrollView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor)
        ])
        
        let contentView = UIView()
        contentView.backgroundColor = .lightGray
        contentView.translatesAutoresizingMaskIntoConstraints = false
        scrollView.addSubview(contentView)
        
        NSLayoutConstraint.activate([
            contentView.topAnchor.constraint(equalTo: scrollView.topAnchor),
            contentView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor),
            contentView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor),
            contentView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor),
            contentView.widthAnchor.constraint(equalTo: scrollView.widthAnchor)
        ])
    }
}

import UIKit

class ContentViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let scrollView = UIScrollView()
        scrollView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(scrollView)
        
        let contentView = UIView()
        contentView.backgroundColor = .white
        contentView.translatesAutoresizingMaskIntoConstraints = false
        scrollView.addSubview(contentView)
        
        let label = UILabel()
        label.text = "This is a long content that requires scrolling"
        label.numberOfLines = 0
        label.translatesAutoresizingMaskIntoConstraints = false
        contentView.addSubview(label)
        
        NSLayoutConstraint.activate([
            scrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            scrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            scrollView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
            
            contentView.topAnchor.constraint(equalTo: scrollView.topAnchor),
            contentView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor),
            contentView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor),
            contentView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor),
            contentView.widthAnchor.constraint(equalTo: scrollView.widthAnchor),
            
            label.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 20),
            label.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 20),
            label.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -20)
        ])
    }
}

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var tableView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.dataSource = self
        tableView.delegate = self
    }
}

extension ViewController: UITableViewDataSource {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 10
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
        cell.textLabel?.text = "Row \(indexPath.row)"
        return cell
    }
}

extension ViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        print("Selected row \(indexPath.row)")
    }
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "customCell", for: indexPath)
    
    cell.textLabel?.text = "Item \(indexPath.row)"
    cell.imageView?.image = UIImage(named: "icon")
    
    return cell
}

import UIKit

class GridViewController: UIViewController {
    @IBOutlet weak var collectionView: UICollectionView!

    override func viewDidLoad() {
        super.viewDidLoad()
        collectionView.delegate = self
        collectionView.dataSource = self
    }
}

extension GridViewController: UICollectionViewDelegate, UICollectionViewDataSource {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 20
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "GridCell", for: indexPath)
        return cell
    }
}

let layout = UICollectionViewFlowLayout()
layout.itemSize = CGSize(width: 100, height: 100)
layout.minimumInteritemSpacing = 10
layout.minimumLineSpacing = 10
layout.sectionInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)

collectionView.collectionViewLayout = layout

let stackView = UIStackView()
stackView.axis = .horizontal
stackView.distribution = .fillEqually
stackView.alignment = .center
stackView.spacing = 10.0

let button1 = UIButton(type: .system)
let button2 = UIButton(type: .system)

stackView.addArrangedSubview(button1)
stackView.addArrangedSubview(button2)

class CustomView: UIView {
    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        print("Hit test called on CustomView")
        return super.hitTest(point, with: event)
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        print("Touches began on CustomView")
        super.touchesBegan(touches, with: event)
    }
}