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WWDC24 · 15 min · App Services / SwiftUI & UI Frameworks

Squeeze the most out of Apple Pencil

New in iOS 18, iPadOS 18, and visionOS 2, the PencilKit tool picker gains the ability to have completely custom tools, with custom attributes. Learn how to express your custom drawing experience in the tool picker using the same great tool picking experience available across the system. Discover how to access the new features of the Apple Pencil Pro, including roll angle, the squeeze gesture, and haptic feedback.

Watch at developer.apple.com ↗

Transcript all transcripts

Chapters

  • 0:00 — Introduction
  • 1:16 — Configuring the tool picker
  • 5:20 — Custom tools in the tool picker
  • 8:47 — Apple Pencil Pro features and APIs

Code shown on screen · 4 snippets

Respond to squeeze in UIKit swift · at 10:24 ↗ 
class MyViewController: UIViewController, UIPencilInteractionDelegate {
    
    func pencilInteraction(_ interaction: UIPencilInteraction, 
               didReceiveSqueeze squeeze: UIPencilInteraction.Squeeze) {

        if UIPencilInteraction.preferredSqueezeAction == .showContextualPalette &&
           squeeze.phase == .ended {
           let anchorPoint = squeeze.hoverPose?.location ?? myDefaultLocation
           presentMyContextualPaletteAtPosition(anchorPoint)
        }
    }
}
Respond to squeeze in SwiftUI swift · at 10:46 ↗ 
@Environment(\.preferredPencilSqueezeAction) var preferredAction
@State var contextualPalettePresented = false
@State var contextualPaletteAnchor = MyPaletteAnchor.default

var body: some View {
    MyView()
        .onPencilSqueeze { phase in
            if preferredAction == .showContextualPalette, case let .ended(value) = phase {
                if let anchorPoint = value.hoverPose?.anchor {
                    contextualPaletteAnchor = .point(anchorPoint)
                }
                contextualPalettePresented = true
            }
        }
}
Provide canvas feedback in UIKit swift · at 11:50 ↗ 
class MyViewController: UIViewController {
    @ViewLoading var feedbackGenerator: UICanvasFeedbackGenerator
    
    override func viewDidLoad() {
        super.viewDidLoad()
        feedbackGenerator = UICanvasFeedbackGenerator(view: view)
    }

    func dragAlignedToGuide(_ sender: MyDragGesture) {
        feedbackGenerator.alignmentOccurred(at: sender.location(in: view))
    }

    func snappedToShape(_ sender: MyDrawGesture) {
        feedbackGenerator.pathCompleted(at: sender.location(in: view))
    }
}
Provide canvas feedback in SwiftUI swift · at 12:29 ↗ 
@State var dragAlignedToGuide = 0
@State var snappedToShape = 0
 var body: some View {
    MyView()
        .sensoryFeedback(.alignment, trigger: dragAlignedToGuide)
        .sensoryFeedback(.pathComplete, trigger: snappedToShape)
}

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