Productivity

iPad multitasking

// Building an "Open in New Window" action
let newSceneAction = UIWindowScene.ActivationAction({ _ in
    // Create the user activity that represents new scene content
    let userActivity = NSUserActivity(activityType: "com.myapp.detailscene")

    // Return activation configuration
    return UIWindowScene.ActivationConfiguration(userActivity: userActivity)
})

Keyboard navigation & shortcuts

iPadOS15

• enable band selection for UICollectionViews that support multi-selection
• Add Pointer accessories
• Keyboard shortcuts
  • Use UIMenuBuilder

    class AppDelegate: UIResponder, UIApplicationDelegate {
      override fund buildMenu(with builder: UIMenuBuilder) {
          // Use the builder to modify the main menu
      }
    }
    

  • Assign categories
  • Audit uses of UIResponder.keyCommands

UI Refinements

• UITabBar: enhance support for SF Symbols

NOTE: need to audit where setting bar’s isTranslucent property to false and check UIViewControllers that have non-standard edgesForExtendedLayout

UIBarAppearance

// Custom scrollEdgeAppearance
let appearance = UITabBarAppearance()
appearance.backgroundEffect = nil
appearance.backgroundColor = .blue
tabBar.scrollEdgeAppearance = appearance

// Specify the content scrollView
let scrollView = ...
viewController.setContentScrollView(scrollView, for: .bottem)

List headers

UIListContentConfiguration API

UIListSeparatorConfiguration

• Advanced customization of separator appearance
  • Visibility
  • Color
  • Insets
• Control over top and bottom separators for each item

Sheet presentations

• Half height sheets
• Optionally non-mondal

UIDatePicker

• Use Keyboard to input

API enhancements

UIButton API

• Style
  • plain
  • gray
  • tinted
  • filled
  • multiple lines (new)
• Menu
  • pull-down
  • pop-up

UIButton.Configuration

// Create SignIn button
let signInButton = UIBUtton(type: .system)
signInButton.configuration = .filled()
signInButton.setTitle("Sign In", for: [])

// create button with UIButton.Configuration
var config = UIButton.Configuration.tinted()

config.title = "Add to Cart"
config.image = UIImage(systemName: "cart.badge.plus")
config.imagePlacement = .trailing
config.buttonSize = .large
config.cornerStyle = .capsule

addToCartButton = UIButton(configuration: config)

// Customize image and subtitle with a configurationUpdateHandler
addToCartButton.configurationUpdateHandler = { [unowned self] button in
    var config = button.configuration
    config?.image = button.isHighlighted
        ? UIImage(systemName: "cart.fill.badge.plus")
        : UIImage(systemName: "cart.badge.plus")
    config?.subtitle = self.itemQuantityDescription
    button.configuration = config
}

// Update when itemQuantityDescription changes
private var itemQuantityDescription: String? {
    didSet {
        addToCartButton.setNeedsUpdateConfiguration()
    }
}

Activity Indicator

• set showActivityIndicator = true in button configuration

Metrics adjustments

Semantic Styling

Toggle Buttons

• preserve a selected state
• already a state of UIControl
• automatically toggles selected

// Toggle button

let stockToggleAction = UIAction(title: "In Stock Only") { _ in
    toggleStock()
}

let button = UIButton(primaryAction: stockToggleAction)
button.changeSelectionAsPrimaryAction = true

button.isSelected = showingOnlyInStock()

Pop-up buttons

• Similar to pull-down buttons
• Enforce a single selected item
• Display selected item

// pop-up button

let colorClosure = { (action: UIAction) in
    updateColor(action.title)
}

let button = UIButton(primaryAction: nil)
button.menu = UIMenu(children: [
    UIAction(title: "Bondi Blue", handler: colorClosure),
    UIAction(title: "Flower Power", state: .on, handler: colorClosure)
])

button.showMenuAsPrimaryAction = true
button.changesSelectionAsPrimaryAction = true

// update to the currently set one
updateColor(button.menu?.selectedElements.first?.title)

// update selection
(button.menu?.children[selectedColorIndex()] as? UIAction)?.state = .on

UIMenu

• subtitles
• improved submenu interaction
• selection management

SF Symbol

In iOS, SF Symbols support Dynamic Type and the Bold Text accessibility feature. SF Symbol available in 3 scales: small, medium and large.

SF symbols are automatically vertically centered to San Francisco’s cap-height in all the different scales and weights.

Enhancements

• monochrome
• hierarchical
• palette
• multicolor

// use a hierarchical color symbol
let configuration = UIImage.SymbolConfiguration(hierarchicalColor: UIColor.systemOrange)

let image = UIImage(systemName: "sun.max.circle.fill", withConfiguration: configuration)

SF Symbol variants

• outline, fill
• slash
• enclosing variants: circle, square, rectangle

• Dynamic tint color: UIColor.tintColor, can using with new UIButton.Configuration and coloful SF Symbols APIs

Others

• Content size category limits
  • restrict dynamic type sizes in view hierarchies
  • set minimum and maximum size

    extension UIView {
    var minimumContentSizeCategory: UIContentSizeCategory
    var maximumContentSizeCategory: UIContentSizeCategory
    }
    

• Color picker enhancements
  • Continuous change
• TextKit2
  • new text layout API
  • used behind scenes in UITextField
• UIScene state restoration
  • NSUserActivity represents interface state
  • State restoration enhancements
    • text interaction state properties
    • callback for restoring state after storyboard load
    • ability to extend state restoration
• Cell configuration closures
  • UICollectionView and UITableView
  • React to changes in cell state

let cell: UICollectionViewCell = ...
cell.configurationUpdateHandler = { cell, state in
    var content = UIListContentConfiguration.cell().updated(for: state)
    if state.isDisabled {
        content.textProperties.color = .systemGray
    }
    cell.contentConfiguration = content
}

• Diffable data source improvements
  • apply snapshots without animation
  • new api to reconfigure items

Performance

Cell prefetching improvements

• behind-the-scenes prefetching changes
• no adoption required
• up to 2x more time to prepare cells

if let image = UIImage(contentOfFile: pathToImage) {
    async {
        let preparedImage = await image.byPreparingForDisplay()
        imageView.image = preparedImage
    }
}

if let bigImage = UIImage(contentsOfFile: pathToBigImage) {
    async {
        let smallImage = await bigImage.byPreparingThumbnail(ofSize: smallSize)
        imageView.image = smallImage
    }
}

Security and privacy

Location Button

• One-time access to location
• Flexible configuration API

Standard paste items

UIResponder selectors and UIAction identifiers for:

• paste
• paste and go
• paste and search
• paste and match style

Private Click Measurement

From iOS 14.5

• Privacy-preserving measurement of ad clicks and taps
• Cover ads with UIEventAttributionViews
• Supply UIEventAttribution when opening a URL

Reference

• https://developer.apple.com/wwdc21/10059
• https://developer.apple.com/wwdc21/10064
• https://developer.apple.com/wwdc21/10097