What’s new in UIKit

// Configuring a calendar view with multi-date selection

let calendarView = UICalendarView()
calendarView.delegate = self
calendarView.calendar = Calendar(identifier: .gregorian)
view.addSubview(calendarView)

let multiDateSelection = UICalendarSelectionMultiDate(delegate: self)
multiDateSelection.selectedDates = myDatabase.selectedDates()
calendarView.selectionBehavior = multiDateSelection

func multiDateSelection(
    _ selection: UICalendarSelectionMultiDate,
    canSelectDate dateComponents: DateComponents
) -> Bool {
    return myDatabase.hasAvailabilities(for: dateComponents)
}

// Configuring Decorations
func calendarView(
    _ calendarView: UICalendarView, 
    decorationFor dateComponents: DateComponents
) -> UICalendarView.Decoration? {
    switch myDatabase.eventType(on: dateComponents) {
    case .none:
        return nil
    case .busy:
        return .default()
    case .travel:
        return .image(airplaneImage, color: .systemOrange)
    case .party:
        return .customView {
            MyPartyEmojiLabel()
        }
    }
}

// Vertical page control with custom indicators

pageControl.direction = .topToBottom
pageControl.preferredIndicatorImage = UIImage(systemNamed: "square")
pageControl.preferredCurrentIndicatorImage = UIImage(systemNamed: "square.fill")

// Create a custom detent
sheet.detents = [
    .large(),
    .custom { _ in
        200.0
    }
]

// Create a custom detent
sheet.detents = [
    .large(),
    .custom { context in
        0.3 * context.maximumDetentValue
    }
]

// Define a custom identifier
extension UISheetPresentationController.Detent.Identifier {
    static let small = UISheetPresentationController.Detent.Identifier("small")
}

// Assign identifier to custom detent
sheet.detents = [
    .large(),
    .custom (identifier: .small) { context in
        0.3 * context.maximumDetentValue
    }
]

// Disable dimming above the custom detent
sheet.largestUndimmedDetentIdentifier = .small

cell.contentConfiguration = UIHostingConfiguration {
    VStack {
        Image(systemName: "wand.and.stars")
            .font(.title)
        Text("Like magic!")
            .font(.title2).bold()
    }
    .foregroundStyle(Color.purple)
}