axiom-swiftui-26-ref

name	axiom-swiftui-26-ref
description	Use when implementing iOS 26 SwiftUI features - covers Liquid Glass design system, performance improvements, @Animatable macro, 3D spatial layout, scene bridging, WebView/WebPage, AttributedString rich text editing, drag and drop enhancements, and visionOS integration for iOS 26+
license	MIT
metadata	{"version":"1.0.0"}

SwiftUI 26 Features

Overview

Comprehensive guide to new SwiftUI features in iOS 26, iPadOS 26, macOS Tahoe, watchOS 26, and visionOS 26. From the Liquid Glass design system to rich text editing, these enhancements make SwiftUI more powerful across all Apple platforms.

Core principle From low level performance improvements all the way up through the buttons in your user interface, there are some major improvements across the system.

When to Use This Skill

• Adopting the Liquid Glass design system
• Implementing rich text editing with AttributedString
• Embedding web content with WebView
• Optimizing list and scrolling performance
• Using the @Animatable macro for custom animations
• Building 3D spatial layouts on visionOS
• Bridging SwiftUI scenes to UIKit/AppKit apps
• Implementing drag and drop with multiple items
• Creating 3D charts with Chart3D
• Adding widgets to visionOS or CarPlay
• Adding custom tick marks to sliders (chapter markers, value indicators)
• Constraining slider selection ranges with enabledBounds
• Customizing slider appearance (thumb visibility, current value labels)
• Creating sticky safe area bars with blur effects
• Opening URLs in in-app browser
• Using system-styled close and confirm buttons
• Applying glass button styles (iOS 26.1+)
• Controlling button sizing behavior
• Implementing compact search toolbars
• Adjusting line height or baseline spacing for text

System Requirements

iOS 26+, iPadOS 26+, macOS Tahoe+, watchOS 26+, visionOS 26+

---

Liquid Glass Design System

For comprehensive coverage, see axiom-liquid-glass (design principles, variants, review pressure) and axiom-liquid-glass-ref (app-wide adoption guide). This section covers WWDC 256-specific APIs only.

Automatic Adoption

Recompile with iOS 26 SDK — navigation containers, tab bars, toolbars, toggles, segmented pickers, and sliders automatically adopt the new design. Bordered buttons default to capsule shape. Sheets get Liquid Glass background (remove any presentationBackground customizations).

Toolbar APIs (iOS 26)

ToolbarSpacer

.toolbar {
    ToolbarItem(placement: .bottomBar) { Button("Archive", systemImage: "archivebox") { } }
    ToolbarSpacer(.flexible, placement: .bottomBar)  // Push items apart
    ToolbarItem(placement: .bottomBar) { Button("Compose", systemImage: "square.and.pencil") { } }
}
// .fixed separates groups visually; .flexible pushes apart (like Spacer in HStack)

ToolbarItemGroup (Visual Grouping)

Items in a ToolbarItemGroup share a single glass background "pill". ToolbarItemPlacement controls visual appearance: confirmationAction → glassProminent styling, cancellationAction → standard glass. Use .sharedBackgroundVisibility(.hidden) to exclude items (e.g., avatars) from group background.

Toolbar Morphing

Attach .toolbar {} to individual views inside NavigationStack (not to NavigationStack itself). iOS 26 morphs between per-view toolbars during push/pop. Use toolbar(id:) with matching ToolbarItem(id:) across screens for items that should stay stable (no bounce):

// MailboxList
.toolbar(id: "main") {
    ToolbarItem(id: "filter", placement: .bottomBar) { Button("Filter") { } }
    ToolbarSpacer(.flexible, placement: .bottomBar)
    ToolbarItem(id: "compose", placement: .bottomBar) { Button("New Message") { } }
}
// MessageList — "filter" absent (animates out), "compose" stays stable
.toolbar(id: "main") {
    ToolbarSpacer(.flexible, placement: .bottomBar)
    ToolbarItem(id: "compose", placement: .bottomBar) { Button("New Message") { } }
}

#1 gotcha: Toolbar on NavigationStack = nothing to morph between.

DefaultToolbarItem

Reposition system-provided items (like search) within your toolbar layout:

DefaultToolbarItem(kind: .search, placement: .bottomBar)
// Replaces system's default placement of matching kind

Use in collapsed NavigationSplitView sidebar to specify which column shows search on iPhone. Wrap in if #available(iOS 26.0, *) for backward compatibility.

User-Customizable Toolbars

toolbar(id:) enables user customization (rearrange, show/hide). Only .secondaryAction items support customization on iPadOS. Use showsByDefault: false for optional items. Add ToolbarCommands() for macOS menu item.

Other Toolbar Features

• .navigationSubtitle("3 unread") — Secondary line below title
• .badge(3) on toolbar items — Notification counts
• Monochrome icon rendering — Reduces visual noise; tint for meaning, not decoration
• Scroll edge blur — Automatic, no code required

Bottom-Aligned Search

Foundational search APIs: See axiom-swiftui-search-ref. This section covers iOS 26 refinements only.

NavigationSplitView {
    List { }.searchable(text: $searchText)
}
// Bottom-aligned on iPhone, top trailing on iPad (automatic)
// Use placement: .sidebar to restore sidebar-embedded search on iPad

• searchToolbarBehavior(.minimize) — Compact search that expands on tap
• Tab(role: .search) — Dedicated search tab; search field replaces tab bar. See swiftui-nav-ref Section 5.7

Glass Effect for Custom Views

Button("To Top", systemImage: "chevron.up") { scrollToTop() }
    .padding()
    .glassEffect()  // Add .interactive for custom controls on iOS

• GlassEffectContainer — Required when multiple glass elements are nearby (glass can't sample glass)
• glassEffectID(_:in:) — Fluid morphing transitions between glass elements using a namespace
• Sheet morphing — Use .matchedTransitionSource + .navigationTransition(.zoom(...)) to morph sheets from buttons

Button & Control Changes

• Capsule shape default for bordered buttons (override with .buttonBorderShape(.roundedRectangle))
• .controlSize(.extraLarge) — New extra-large button size
• .controlSize(.small) on containers — Preserve pre-iOS 26 density
• GlassButtonStyle(.clear/.glass/.tint) — Glass button variants (iOS 26.1+)
• .buttonSizing(.fit/.stretch/.flexible) — Control button layout behavior
• Button(role: .close) / Button(role: .confirm) — System-styled close/confirm
• .clipShape(.rect(cornerRadius: 12, style: .containerConcentric)) — Corner concentricity
• Menus: icons on leading edge, consistent iOS/macOS

---

Slider Enhancements

iOS 26 adds custom tick marks, constrained selection ranges, current value labels, and thumb visibility control.

Slider Ticks

Core types: SliderTick<V>, SliderTickContentForEach, SliderTickBuilder

// Static ticks with labels
Slider(value: $value, in: 0...10) {
    Text("Rating")
} ticks: {
    SliderTick(0) { Text("Min") }
    SliderTick(5) { Text("Mid") }
    SliderTick(10) { Text("Max") }
}

// Dynamic ticks from collection
SliderTickContentForEach(stops, id: \.self) { value in
    SliderTick(value) { Text("\(Int(value))°").font(.caption2) }
}

// Step-based ticks (called for each step value)
Slider(value: $volume, in: 0...10, step: 2, label: { Text("Volume") }, tick: { value in
    SliderTick(value) { Text("\(Int(value))") }
})

API constraint: SliderTickContentForEach requires Data.Element to match SliderTick<V> value type. For custom structs, extract numeric values: chapters.map(\.time) then look up labels via chapters.first(where: { $0.time == time }).

Full-Featured Slider

Slider(
    value: $rating, in: 0...100,
    neutralValue: 50,           // Starting point / center value
    enabledBounds: 20...80,     // Restrict selectable range
    label: { Text("Rating") },
    currentValueLabel: { Text("\(Int(rating))") },
    minimumValueLabel: { Text("0") },
    maximumValueLabel: { Text("100") },
    ticks: { SliderTick(50) { Text("Mid") } },
    onEditingChanged: { editing in print(editing ? "Started" : "Ended") }
)

sliderThumbVisibility

.sliderThumbVisibility(.hidden) — Hide thumb for media progress indicators and minimal UI. Options: .automatic, .visible, .hidden. Always visible on watchOS.

---

New View Modifiers

safeAreaBar

Sticky bars with integrated progressive blur:

List { ForEach(1...20, id: \.self) { Text("\($0). Item") } }
    .safeAreaBar(edge: .bottom) {
        Text("Bottom Action Bar").padding(.vertical, 15)
    }
    .scrollEdgeEffectStyle(.soft, for: .bottom) // or .hard

Works like safeAreaInset but with blur. Bar remains fixed while content scrolls beneath.

onOpenURL Enhancement

@Environment(\.openURL) var openURL
// openURL(url, prefersInApp: true) — Opens in SFSafariViewController-style in-app browser
// Default Link opens in Safari; prefersInApp keeps users in your app

searchToolbarBehavior

See axiom-swiftui-search-ref for foundational .searchable APIs. iOS 26 adds:

.searchable(text: $searchText)
.searchToolbarBehavior(.minimize)  // Compact button, expands on tap

Also: .searchPresentationToolbarBehavior(.avoidHidingContent) (iOS 17.1+) keeps title visible during search.

Backward-compatible wrapper for apps targeting iOS 18+26:

extension View {
    @ViewBuilder func minimizedSearch() -> some View {
        if #available(iOS 26.0, *) {
            self.searchToolbarBehavior(.minimize)
        } else { self }
    }
}

// Usage
.searchable(text: $searchText)
.minimizedSearch()

Availability pattern for toolbar items:

.toolbar {
    if #available(iOS 26.0, *) {
        DefaultToolbarItem(kind: .search, placement: .bottomBar)
        ToolbarSpacer(.flexible, placement: .bottomBar)
    }
    ToolbarItem(placement: .bottomBar) {
        NewNoteButton()
    }
}
.searchable(text: $searchText)

Button roles, GlassButtonStyle, buttonSizing — See Liquid Glass Design System section above.

lineHeight (iOS 26)

Sets the baseline-to-baseline distance between text lines. More intuitive than .lineSpacing() which measures bottom-of-line to top-of-next-line.

Presets

Text("Lorem ipsum...")
    .lineHeight(.loose)     // Increased spacing for open layouts
    .lineHeight(.tight)     // Reduced spacing for compact layouts
    .lineHeight(.normal)    // Constant height based on point size multiple
    .lineHeight(.variable)  // Uses font metrics for height calculation

Precise Control

// Scale proportionally to font size
Text("Scales with text size")
    .lineHeight(.multiple(factor: 2))

// Relative to point size with fixed increase
Text("Point-size relative")
    .lineHeight(.leading(increase: 30))

// Absolute fixed value — does NOT scale with Dynamic Type
Text("Fixed height")
    .lineHeight(.exact(points: 30))

AttributedString Support

var s = AttributedString("Paragraph\nwith multiple\nlines.")
s.lineHeight = .exact(points: 32)
s.lineHeight = .multiple(factor: 2.5)
s.lineHeight = .loose

Comparison with Existing APIs

API	Measures	Available
.lineHeight()	Baseline to baseline	iOS 26+
.lineSpacing()	Bottom of line to top of next	iOS 13+
.font(.body.leading(.tight))	Font-level leading preset	iOS 14+

Cross-reference axiom-typography-ref — Full typography system including Dynamic Type, tracking, and internationalization

---

iPad Enhancements

Menu Bar

Access common actions via swipe-down menu

.commands {
    TextEditingCommands() // Same API as macOS menu bar

    CommandGroup(after: .newItem) {
        Button("Add Note") {
            addNote()
        }
        .keyboardShortcut("n", modifiers: [.command, .shift])
    }
}
// Creates menu bar on iPad when people swipe down

Resizable Windows

Fluid resizing on iPad

// MIGRATION REQUIRED:
// Remove deprecated property list key in iPadOS 26:
// UIRequiresFullscreen (entire key deprecated, all values)

// For split view navigation, system automatically shows/hides columns
// based on available space during resize
NavigationSplitView {
    Sidebar()
} detail: {
    Detail()
}
// Adapts to resizing automatically

Reference "Elevate the design of your iPad app" (WWDC 2025)

---

macOS Window Enhancements

Synchronized Window Resize Animations

.windowResizeAnchor(.topLeading) // Tailor where animation originates

// SwiftUI now synchronizes animation between content view size changes
// and window resizing - great for preserving continuity when switching tabs

---

Performance Improvements

List Performance (macOS Focus)

Massive gains for large lists

• 6x faster loading for lists of 100,000+ items on macOS
• 16x faster updates for large lists
• Even bigger gains for larger lists
• Improvements benefit all platforms (iOS, iPadOS, watchOS)

List(trips) { trip in // 100k+ items
    TripRow(trip: trip)
}
// Loads 6x faster, updates 16x faster on macOS (iOS 26+)

Scrolling Performance

Reduced dropped frames

SwiftUI has improved scheduling of user interface updates on iOS and macOS. This improves responsiveness and lets SwiftUI do even more work to prepare for upcoming frames. All in all, it reduces the chance of your app dropping a frame while scrolling quickly at high frame rates.

Nested ScrollViews with Lazy Stacks

Photo carousels and multi-axis scrolling

ScrollView(.horizontal) {
    LazyHStack {
        ForEach(photoSets) { photoSet in
            ScrollView(.vertical) {
                LazyVStack {
                    ForEach(photoSet.photos) { photo in
                        PhotoView(photo: photo)
                    }
                }
            }
        }
    }
}
// Nested scrollviews now properly delay loading with lazy stacks
// Great for building photo carousels

SwiftUI Performance Instrument

New profiling tool in Xcode

Available lanes:

• Long view body updates — Identify expensive body computations
• Platform view updates — Track UIKit/AppKit bridging performance
• Other performance problem areas

Reference "Optimize SwiftUI performance with instruments" (WWDC 2025)

Cross-reference SwiftUI Performance — Master the SwiftUI Instrument

---

Swift Concurrency Integration

Compile-Time Data Race Safety

@Observable
class TripStore {
    var trips: [Trip] = []

    func loadTrips() async {
        trips = await TripService.fetchTrips()
        // Swift 6 verifies data race safety at compile time
    }
}

Benefits Find bugs in concurrent code before they affect your app

References

• "Embracing Swift concurrency" (WWDC 2025)
• "Explore concurrency in SwiftUI" (WWDC 2025)

Cross-reference Swift Concurrency — Swift 6 strict concurrency patterns

---

@Animatable Macro

Overview

Simplifies custom animations by automatically synthesizing animatableData property.

Before (@Animatable macro)

struct HikingRouteShape: Shape {
    var startPoint: CGPoint
    var endPoint: CGPoint
    var elevation: Double
    var drawingDirection: Bool // Don't want to animate this

    // Tedious manual animatableData declaration
    var animatableData: AnimatablePair<CGPoint.AnimatableData,
                        AnimatablePair<Double, CGPoint.AnimatableData>> {
        get {
            AnimatablePair(startPoint.animatableData,
                          AnimatablePair(elevation, endPoint.animatableData))
        }
        set {
            startPoint.animatableData = newValue.first
            elevation = newValue.second.first
            endPoint.animatableData = newValue.second.second
        }
    }
}

After (@Animatable macro)

@Animatable
struct HikingRouteShape: Shape {
    var startPoint: CGPoint
    var endPoint: CGPoint
    var elevation: Double

    @AnimatableIgnored
    var drawingDirection: Bool // Excluded from animation

    // animatableData automatically synthesized!
}

Key benefits

• Delete manual animatableData property
• Use @AnimatableIgnored for properties to exclude
• SwiftUI automatically synthesizes animation data

Cross-reference SwiftUI Animation (swiftui-animation-ref skill) — Comprehensive animation guide covering VectorArithmetic, Animatable protocol, @Animatable macro, animation types, Transaction system, and performance optimization

---

3D Spatial Layout (visionOS)

Alignment3D

Depth-based layout

struct SunPositionView: View {
    @State private var timeOfDay: Double = 12.0

    var body: some View {
        HikingRouteView()
            .overlay(alignment: sunAlignment) {
                SunView()
                    .spatialOverlay(alignment: sunAlignment)
            }
    }

    var sunAlignment: Alignment3D {
        // Align sun in 3D space based on time of day
        Alignment3D(
            horizontal: .center,
            vertical: .top,
            depth: .back
        )
    }
}

Manipulable Modifier

Interactive 3D objects

Model3D(named: "WaterBottle")
    .manipulable() // People can pick up and move the object

Surface Snapping APIs

@Environment(\.surfaceSnappingInfo) var snappingInfo: SurfaceSnappingInfo

var body: some View {
    VStackLayout().depthAlignment(.center) {
        Model3D(named: "waterBottle")
            .manipulable()

        Pedestal()
            .opacity(snappingInfo.classification == .table ? 1.0 : 0.0)
    }
}

References

• "Meet SwiftUI spatial layout" (WWDC 2025)
• "Set the scene with SwiftUI in visionOS" (WWDC 2025)
• "What's new in visionOS" (WWDC 2025)

---

Scene Bridging

Overview

Scene bridging allows your UIKit and AppKit lifecycle apps to interoperate with SwiftUI scenes. Apps can use it to open SwiftUI-only scene types or use SwiftUI-exclusive features right from UIKit or AppKit code.

Supported Scene Types

From UIKit/AppKit apps, you can now use

• MenuBarExtra (macOS)
• ImmersiveSpace (visionOS)
• RemoteImmersiveSpace (macOS → Vision Pro)
• AssistiveAccess (iOS 26)

Scene Modifiers

Works with scene modifiers like:

• .windowStyle()
• .immersiveEnvironmentBehavior()

RemoteImmersiveSpace

Mac app renders stereo content on Vision Pro

// In your macOS app
@main
struct MyMacApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }

        RemoteImmersiveSpace(id: "stereoView") {
            // Render stereo content on Apple Vision Pro
            // Uses CompositorServices
        }
    }
}

Features

• Mac app renders stereo content on Vision Pro
• Hover effects and input events supported
• Uses CompositorServices and Metal

Reference "What's new in Metal rendering for immersive apps" (WWDC 2025)

AssistiveAccess Scene

Special mode for users with cognitive disabilities

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }

        AssistiveAccessScene {
            SimplifiedUI() // UI shown when iPhone is in AssistiveAccess mode
        }
    }
}

Reference "Customize your app for Assistive Access" (WWDC 2025)

---

AppKit Integration Enhancements

SwiftUI Sheets in AppKit

// Show SwiftUI view in AppKit sheet
let hostingController = NSHostingController(rootView: SwiftUISettingsView())
presentAsSheet(hostingController)
// Great for incremental SwiftUI adoption

NSGestureRecognizerRepresentable

// Bridge AppKit gestures to SwiftUI
struct AppKitPanGesture: NSGestureRecognizerRepresentable {
    func makeNSGestureRecognizer(context: Context) -> NSPanGestureRecognizer {
        NSPanGestureRecognizer()
    }

    func updateNSGestureRecognizer(_ recognizer: NSPanGestureRecognizer, context: Context) {
        // Update configuration
    }
}

NSHostingView in Interface Builder

NSHostingView can now be used directly in Interface Builder for gradual SwiftUI adoption.

---

RealityKit Integration

Observable Entities

@Observable
class RealityEntity {
    var position: SIMD3<Float>
    var rotation: simd_quatf
}

struct MyView: View {
    @State private var entity = RealityEntity()

    var body: some View {
        // SwiftUI views automatically observe changes
        Text("Position: \(entity.position.x)")
    }
}

PresentationComponent

Present SwiftUI popovers, alerts, and sheets directly from RealityKit entities.

// Present SwiftUI popovers from RealityKit entities
let popover = Entity()
mapEntity.addChild(popover)
popover.components[PresentationComponent.self] = PresentationComponent(
    isPresented: $popoverPresented,
    configuration: .popover(arrowEdge: .bottom),
    content: DetailsView()
)

Additional Improvements

• ViewAttachmentComponent — add SwiftUI views to entities
• GestureComponent — entity touch and gesture responsiveness
• Enhanced coordinate conversion API
• Synchronizing animations, binding to components
• New sizing behaviors for RealityView

Reference "Better Together: SwiftUI & RealityKit" (WWDC 2025)

---

WebView & WebPage

Overview

WebKit now provides full SwiftUI APIs for embedding web content, eliminating the need to drop down to UIKit.

WebView

Display web content

import WebKit

struct ArticleView: View {
    let articleURL: URL

    var body: some View {
        WebView(url: articleURL)
    }
}

WebPage (Observable Model)

Rich interaction with web content

import WebKit

struct InAppBrowser: View {
    @State private var page = WebPage()

    var body: some View {
        VStack {
            Text(page.title ?? "Loading...")

            WebView(page)
                .ignoresSafeArea()
                .onAppear {
                    page.load(URLRequest(url: articleURL))
                }

            HStack {
                Button("Back") { page.goBack() }
                    .disabled(!page.canGoBack)
                Button("Forward") { page.goForward() }
                    .disabled(!page.canGoForward)
            }
        }
    }
}

WebPage features

• Programmatic navigation (goBack(), goForward())
• Access page properties (title, url, canGoBack, canGoForward)
• Observable — SwiftUI views update automatically

tvOS: WebView and WebPage are not available on tvOS. tvOS has no WKWebView at all. For web content parsing on tvOS, use JavaScriptCore. See axiom-tvos for alternatives.

Advanced WebKit Features

• Custom user agents
• JavaScript execution
• Custom URL schemes
• And more

Reference "Meet WebKit for SwiftUI" (WWDC 2025)

---

TextEditor with AttributedString

Overview

SwiftUI's new support for rich text editing is great for experiences like commenting on photos. TextView now supports AttributedString!

Note The WWDC transcript uses "TextView" as editorial language. The actual SwiftUI API is TextEditor which now supports AttributedString binding for rich text editing.

Plain Text vs Rich Text

• For plain text: Prefer TextField("Label", text: $text, axis: .vertical) over TextEditor — supports placeholder text, consistent styling, and automatic vertical expansion (iOS 16+)
• For rich text: Use TextEditor with AttributedString binding (iOS 26+) — TextField does not support AttributedString

Rich Text Editing

struct CommentView: View {
    @State private var comment = AttributedString("Enter your comment")

    var body: some View {
        TextEditor(text: $comment)
            // Built-in text formatting controls included
            // Users can apply bold, italic, underline, etc.
    }
}

Features

• Built-in text formatting controls (bold, italic, underline, colors, etc.)
• Binding to AttributedString preserves formatting
• Automatic toolbar with formatting options

Advanced AttributedString Features

Customization options

• Paragraph styles
• Attribute transformations
• Constrain which attributes users can apply

Reference "Cook up a rich text experience in SwiftUI with AttributedString" (WWDC 2025)

Cross-reference App Intents Integration (app-intents-ref skill) — AttributedString for Apple Intelligence Use Model action

---

Drag and Drop Enhancements

Multiple Item Dragging

Drag multiple items based on selection

struct PhotoGrid: View {
    @State private var selectedPhotos: [Photo.ID] = []

    var body: some View {
        ScrollView {
            LazyVGrid(columns: gridColumns) {
                ForEach(model.photos) { photo in
                    view(photo: photo)
                        .draggable(containerItemID: photo.id)
                }
            }
        }
        .dragContainer(for: Photo.self, selection: selectedPhotos) { draggedIDs in
            photos(ids: draggedIDs)
        }
    }
}

Key APIs:

• .draggable(containerItemID:containerNamespace:) marks each item as part of a drag container (namespace defaults to nil)
• .dragContainer(for:selection:) provides the typed items lazily when a drop occurs

DragConfiguration

Customize supported operations

.dragConfiguration(DragConfiguration(allowMove: false, allowDelete: true))

Observing Drag Events

.onDragSessionUpdated { session in
    let ids = session.draggedItemIDs(for: Photo.ID.self)
    if session.phase == .ended(.delete) {
        trash(ids)
        deletePhotos(ids)
    }
}

Drag Preview Formations

.dragPreviewsFormation(.stack) // Items stack nicely on top of one another

// Other formations:
// - .default
// - .grid
// - .stack

Combine all modifiers (.dragContainer, .dragConfiguration, .dragPreviewsFormation, .onDragSessionUpdated) on the same scroll view for a complete multi-item drag experience.

---

3D Charts

Overview

Swift Charts supports three-dimensional plotting with Chart3D. Key components: Chart3D (container), SurfacePlot (continuous surfaces), Chart3DPose (camera control), Chart3DSurfaceStyle (surface appearance).

Chart3D Container

import Charts

Chart3D {
    SurfacePlot(x: "x", y: "y", z: "z") { x, y in
        sin(x) * cos(y)
    }
    .foregroundStyle(Gradient(colors: [.orange, .pink]))
}
.chartXScale(domain: -3...3)
.chartYScale(domain: -3...3)
.chartZScale(domain: -3...3)

Chart3D also accepts data collections:

Chart3D(dataPoints) { point in
    // 3D mark for each data point
}

SurfacePlot

Renders continuous surfaces from a mathematical function mapping (x, y) to z values.

SurfacePlot(x: "X Axis", y: "Y Axis", z: "Z Axis") { x, y in
    sin(sqrt(x * x + y * y))
}

Surface Styling

SurfacePlot(x: "X", y: "Y", z: "Z") { x, y in sin(x) * cos(y) }
    .foregroundStyle(.blue)                        // Solid color
    .roughness(0.3)                                // 0 = smooth, 1 = rough

// Height-based coloring (color maps to z-value)
    .foregroundStyle(Chart3DSurfaceStyle.heightBased(yRange: -1.0...1.0))

// Custom gradient mapped to height
    .foregroundStyle(Chart3DSurfaceStyle.heightBased(
        Gradient(colors: [.blue, .green, .yellow, .red]),
        yRange: -1.0...1.0
    ))

Available surface styles: .heightBased (color by z-value), .normalBased (color by surface normal direction).

Multiple Surfaces

Chart3D {
    SurfacePlot(x: "X", y: "Y", z: "Z") { x, y in sin(x) * cos(y) }
    SurfacePlot(x: "X", y: "Y", z: "Z") { x, y in cos(x) * sin(y) + 2 }
}

Chart3DPose (Camera Control)

Controls the viewing angle. Pass as value for static positioning, or bind for interactive rotation.

@State private var chartPose: Chart3DPose = .default

Chart3D { /* ... */ }
    .chart3DPose(chartPose)      // Static — read-only
    .chart3DPose($chartPose)     // Binding — enables drag-to-rotate

Predefined poses: .default, .front, .back, .top, .bottom, .left, .right

Custom pose with specific angles:

Chart3DPose(azimuth: .degrees(45), inclination: .degrees(30))

Animate between poses:

Button("Top View") { withAnimation { chartPose = .top } }

Chart3DCameraProjection

Controls how 3D depth is projected to 2D.

Chart3D { /* ... */ }
    .chart3DCameraProjection(.perspective)    // Objects shrink with distance
    .chart3DCameraProjection(.orthographic)   // Objects maintain size regardless of depth
    .chart3DCameraProjection(.automatic)      // System decides

Z-Axis Modifiers

All existing chart axis modifiers have z-axis equivalents:

• .chartZScale(domain:) — Set z-axis range
• .chartZAxis() — Configure z-axis labels and grid lines

Reference "Bring Swift Charts to the third dimension" (WWDC 2025)

---

Widgets & Controls

Controls on watchOS and macOS

watchOS 26

struct FavoriteLocationControl: ControlWidget {
    var body: some ControlWidgetConfiguration {
        StaticControlConfiguration(kind: "FavoriteLocation") {
            ControlWidgetButton(action: MarkFavoriteIntent()) {
                Label("Mark Favorite", systemImage: "star")
            }
        }
    }
}
// Access from watch face or Shortcuts

macOS

Controls now appear in Control Center on Mac.

Widgets on visionOS

Level of detail customization

struct CountdownWidget: Widget {
    var body: some WidgetConfiguration {
        StaticConfiguration(kind: "Countdown") { entry in
            CountdownView(entry: entry)
        }
    }
}

struct PhotoCountdownView: View {
    @Environment(\.levelOfDetail) var levelOfDetail: LevelOfDetail

    var body: some View {
        switch levelOfDetail {
        case .default:
            RecentPhotosView() // Full detail when close
        case .simplified:
            CountdownView()   // Simplified when further away
        default:
            CountdownView()
        }
    }
}

Widgets on CarPlay

Live Activities on CarPlay

Live Activities now appear on CarPlay displays for glanceable information while driving.

Additional Widget Features

• Push-based updating API
• New relevance APIs for watchOS

Reference "What's new in widgets" (WWDC 2025)

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Migration Checklist

Deprecated APIs

❌ Remove in iPadOS 26

<key>UIRequiresFullscreen</key>
<!-- Entire property list key is deprecated (all values) -->

Apps must support resizable windows on iPad.

Automatic Adoptions (Recompile Only)

✅ Liquid Glass design for navigation, tab bars, toolbars ✅ Bottom-aligned search on iPhone ✅ List performance improvements (6x loading, 16x updating) ✅ Scrolling performance improvements ✅ System controls (toggles, pickers, sliders) new appearance ✅ Bordered buttons default to capsule shape ✅ Updated control heights (slightly taller on macOS) ✅ Monochrome icon rendering in toolbars ✅ Menus: icons on leading edge, consistent across iOS and macOS ✅ Sheets morph out of dialogs automatically ✅ Scroll edge blur/fade under system toolbars

Audit Items (Remove Old Customizations)

⚠️ Remove presentationBackground from sheets (let Liquid Glass material shine) ⚠️ Remove extra backgrounds/darkening effects behind toolbar areas ⚠️ Remove hard-coded control heights (use automatic sizing) ⚠️ Update section headers to title-style capitalization (no longer auto-uppercased)

Manual Adoptions (Code Changes)

🔧 Toolbar spacers (.fixed) 🔧 Tinted prominent buttons in toolbars 🔧 Glass effect for custom views (.glassEffect()) 🔧 glassEffectID for morphing transitions between glass elements 🔧 GlassEffectContainer for multiple nearby glass elements 🔧 sharedBackgroundVisibility(.hidden) to remove toolbar item from group background 🔧 Sheet morphing from buttons (navigationZoomTransition) 🔧 Search tab role (Tab(role: .search)) 🔧 Compact search toolbar (.searchToolbarBehavior(.minimize)) 🔧 Extra large buttons (.controlSize(.extraLarge)) 🔧 Concentric rectangle shape (.containerConcentric) 🔧 iPad menu bar (.commands) 🔧 Window resize anchor (.windowResizeAnchor()) 🔧 @Animatable macro for custom shapes/modifiers 🔧 WebView for web content 🔧 TextEditor with AttributedString binding 🔧 Enhanced drag and drop with .dragContainer 🔧 Slider ticks (SliderTick, SliderTickContentForEach) 🔧 Slider thumb visibility (.sliderThumbVisibility()) 🔧 Safe area bars with blur (.safeAreaBar() + .scrollEdgeEffectStyle()) 🔧 In-app URL opening (openURL(url, prefersInApp: true)) 🔧 Close and confirm button roles (Button(role: .close)) 🔧 Glass button styles (GlassButtonStyle — iOS 26.1+) 🔧 Button sizing control (.buttonSizing()) 🔧 Toolbar morphing transitions (per-view .toolbar {} inside NavigationStack) 🔧 DefaultToolbarItem for system components in toolbars 🔧 Stable toolbar items (toolbar(id:) with matched IDs across screens) 🔧 User-customizable toolbars (toolbar(id:) with CustomizableToolbarContent) 🔧 Line height control (.lineHeight() — baseline-to-baseline distance) 🔧 Tab bar minimization (.tabBarMinimizeBehavior(.onScrollDown)) 🔧 Tab view bottom accessory (.tabViewBottomAccessory(isEnabled:content:) — iOS 26.1+)

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Best Practices

• Performance: Profile with new SwiftUI Instrument; use lazy stacks in nested ScrollViews; trust automatic list performance improvements
• Liquid Glass: Recompile and test first; use toolbar spacers; attach .toolbar {} to individual views (not NavigationStack); remove presentationBackground from sheets; use GlassEffectContainer for nearby glass elements
• Layout: Use .safeAreaPadding() for edge-to-edge (not .padding()). See axiom-swiftui-layout-ref for full guide
• Rich Text: Bind AttributedString to TextEditor; constrain attributes for your UX
• Spatial (visionOS): Use Alignment3D for depth; .manipulable() only where it makes sense

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Troubleshooting

Symptom	Fix
Old design after updating to iOS 26 SDK	Clean build (Shift-Cmd-K), rebuild targeting iOS 26 SDK, check deployment target
Search remains at top on iPhone	Place .searchable on NavigationSplitView, not on List directly
@Animatable "does not conform"	All properties must be VectorArithmetic or marked @AnimatableIgnored
Rich text formatting lost in TextEditor	Bind AttributedString, not String
Drag delete not working	Enable .dragConfiguration(allowDelete: true) AND observe .onDragSessionUpdated
SliderTickContentForEach won't compile	Iterate over numeric values (chapters.map(\.time)), not custom structs — see Slider section
Toolbar not morphing during navigation	Move .toolbar {} from NavigationStack to each view inside it — see Liquid Glass section

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Resources

WWDC: 2025-256, 2025-278 (What's new in widgets), 2025-287 (Meet WebKit for SwiftUI), 2025-310 (Optimize SwiftUI performance with instruments), 2025-323 (Build a SwiftUI app with the new design), 2025-325 (Bring Swift Charts to the third dimension), 2025-341 (Cook up a rich text experience in SwiftUI with AttributedString)

Docs: /swiftui, /swiftui/defaulttoolbaritem, /swiftui/toolbarspacer, /swiftui/searchtoolbarbehavior, /swiftui/view/toolbar(id:content:), /swiftui/view/tabbarminimizebehavior(_:), /swiftui/view/tabviewbottomaccessory(isenabled:content:), /swiftui/slider, /swiftui/slidertick, /swiftui/slidertickcontentforeach, /webkit, /foundation/attributedstring, /charts, /charts/chart3d, /charts/surfaceplot, /charts/chart3dpose, /charts/chart3dcameraprojection, /charts/chart3dsurfacestyle, /realitykit/presentationcomponent

Skills: axiom-swiftui-performance, axiom-liquid-glass, axiom-swift-concurrency, axiom-app-intents-ref, axiom-swiftui-search-ref

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Primary source WWDC 2025-256 "What's new in SwiftUI". Additional content from 2025-323 (Build a SwiftUI app with the new design), 2025-287 (Meet WebKit for SwiftUI), and Apple documentation. Version iOS 26+, iPadOS 26+, macOS Tahoe+, watchOS 26+, visionOS 26+