SwiftUI Animation

Overview

Comprehensive guide to SwiftUI’s animation system, from foundational concepts to advanced techniques. This skill covers the Animatable protocol, the iOS 26 @Animatable macro, animation types, and the Transaction system.

Core principle Animation in SwiftUI is mathematical interpolation over time, powered by the VectorArithmetic protocol. Understanding this foundation unlocks the full power of SwiftUI’s declarative animation system.

System Requirements

• iOS 13+: Animatable protocol, timing/spring animations
• iOS 17+: Default spring animations, scoped animations, PhaseAnimator, KeyframeAnimator
• iOS 18+: Zoom transitions, UIKit/AppKit animation bridging
• iOS 26+: @Animatable macro

Part 1: Understanding Animation

What Is Interpolation

Animation is the process of generating intermediate values between a start and end state.

Example: Opacity animation

.opacity(0) → .opacity(1)

While this animation runs, SwiftUI computes intermediate values:

0.0 → 0.02 → 0.05 → 0.1 → 0.25 → 0.4 → 0.6 → 0.8 → 1.0

How values are distributed

• Determined by the animation’s timing curve or velocity function
• Spring animations use physics simulation
• Timing curves use bezier curves
• Each animation type calculates values differently

VectorArithmetic Protocol

SwiftUI requires animated data to conform to VectorArithmetic — providing subtraction, scaling, addition, and a zero value. This enables SwiftUI to interpolate between any two values.

Built-in conforming types: CGFloat, Double, Float, Angle (1D), CGPoint, CGSize (2D), CGRect (4D).

Key insight Vector arithmetic abstracts over dimensionality. SwiftUI animates all these types with a single generic implementation.

Why Int Can’t Be Animated

Int doesn’t conform to VectorArithmetic — no fractional intermediates exist between 3 and 4. SwiftUI simply snaps the value.

Solution: Use Float/Double and display as Int:

@State private var count: Float = 0
// ...
Text("\(Int(count))")
    .animation(.spring, value: count)

Model vs Presentation Values

Animatable attributes conceptually have two values:

Model Value

• The target value set by your code
• Updated immediately when state changes
• What you write in your view’s body

Presentation Value

• The current interpolated value being rendered
• Updates frame-by-frame during animation
• What the user actually sees

Example

.scaleEffect(selected ? 1.5 : 1.0)

When selected becomes true:

• Model value: Immediately becomes 1.5
• Presentation value: Interpolates 1.0 → 1.1 → 1.2 → 1.3 → 1.4 → 1.5 over time

Part 2: Animatable Protocol

Overview

The Animatable protocol allows views to animate their properties by defining which data should be interpolated.

protocol Animatable {
    associatedtype AnimatableData: VectorArithmetic

    var animatableData: AnimatableData { get set }
}

SwiftUI builds an animatable attribute for any view conforming to this protocol.

Built-in Animatable Views

Many SwiftUI modifiers conform to Animatable:

Visual Effects

• .scaleEffect() — Animates scale transform
• .rotationEffect() — Animates rotation
• .offset() — Animates position offset
• .opacity() — Animates transparency
• .blur() — Animates blur radius
• .shadow() — Animates shadow properties

All Shape types

• Circle, Rectangle, RoundedRectangle
• Capsule, Ellipse, Path
• Custom Shape implementations

AnimatablePair for Multi-Dimensional Data

When animating multiple properties, use AnimatablePair to combine vectors. For example, scaleEffect combines CGSize (2D) and UnitPoint (2D) into a 4D vector via AnimatablePair<CGSize.AnimatableData, UnitPoint.AnimatableData>. Access components via .first and .second. The @Animatable macro (iOS 26+) eliminates this boilerplate entirely.

Custom Animatable Conformance

When to use

• Animating custom layout (like RadialLayout)
• Animating custom drawing code
• Animating properties that affect shape paths

Example: Animated number view

struct AnimatableNumberView: View, Animatable {
    var number: Double

    var animatableData: Double {
        get { number }
        set { number = newValue }
    }

    var body: some View {
        Text("\(Int(number))")
            .font(.largeTitle)
    }
}

// Usage
AnimatableNumberView(number: value)
    .animation(.spring, value: value)

How it works

1. number changes from 0 to 100
2. SwiftUI calls body for every frame of the animation
3. Each frame gets a new number value: 0 → 5 → 15 → 30 → 55 → 80 → 100
4. Text updates to show the interpolated integer

Performance Warning

Custom Animatable conformance is expensive — SwiftUI calls body for every frame on the main thread. Built-in effects (.scaleEffect(), .opacity()) run off-main-thread and don’t call body. Use custom conformance only when built-in modifiers can’t achieve the effect (e.g., animating a custom Layout that repositions subviews per-frame).

Part 3: @Animatable Macro (iOS 26+)

Overview

The @Animatable macro eliminates the boilerplate of manually conforming to the Animatable protocol.

Before iOS 26, you had to:

1. Manually conform to Animatable
2. Write animatableData getter and setter
3. Use AnimatablePair for multiple properties
4. Exclude non-animatable properties manually

iOS 26+, you just add @Animatable:

@MainActor
@Animatable
struct MyView: View {
    var scale: CGFloat
    var opacity: Double

    var body: some View {
        // ...
    }
}

The macro automatically:

• Generates Animatable conformance
• Inspects all stored properties
• Creates animatableData from VectorArithmetic-conforming properties
• Handles multi-dimensional data with AnimatablePair

Before/After Comparison

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<AnimatablePair<CGFloat, CGFloat>,
                        AnimatablePair<Double, AnimatablePair<CGFloat, CGFloat>>> {
        get {
            AnimatablePair(
                AnimatablePair(startPoint.x, startPoint.y),
                AnimatablePair(elevation, AnimatablePair(endPoint.x, endPoint.y))
            )
        }
        set {
            startPoint = CGPoint(x: newValue.first.first, y: newValue.first.second)
            elevation = newValue.second.first
            endPoint = CGPoint(x: newValue.second.second.first, y: newValue.second.second.second)
        }
    }

    func path(in rect: CGRect) -> Path {
        // Drawing code
    }
}

After @Animatable macro

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

    @AnimatableIgnored
    var drawingDirection: Bool // Excluded from animation

    func path(in rect: CGRect) -> Path {
        // Drawing code
    }
}

Lines of code: 20 → 12 (40% reduction)

@AnimatableIgnored

Use @AnimatableIgnored to exclude properties from animation.

When to use

• Debug values — Flags for development only
• IDs — Identifiers that shouldn’t animate
• Timestamps — When the view was created/updated
• Internal state — Non-visual bookkeeping
• Non-VectorArithmetic types — Colors, strings, booleans

Example

@MainActor
@Animatable
struct ProgressView: View {
    var progress: Double // Animated
    var totalItems: Int // Animated (if Float, not if Int)

    @AnimatableIgnored
    var title: String // Not animated

    @AnimatableIgnored
    var startTime: Date // Not animated

    @AnimatableIgnored
    var debugEnabled: Bool // Not animated

    var body: some View {
        VStack {
            Text(title)
            ProgressBar(value: progress)
            if debugEnabled {
                Text("Started: \(startTime.formatted())")
            }
        }
    }
}

Real-World Use Case

@Animatable works for any numeric display — stock prices, heart rate, scores, timers, progress bars:

@MainActor
@Animatable
struct AnimatedValueView: View {
    var value: Double
    var changePercent: Double

    @AnimatableIgnored
    var label: String

    var body: some View {
        VStack(alignment: .trailing) {
            Text("\(value, format: .number.precision(.fractionLength(2)))")
                .font(.title)
            Text("\(changePercent > 0 ? "+" : "")\(changePercent, format: .percent)")
                .foregroundStyle(changePercent > 0 ? .green : .red)
        }
    }
}

// Usage
AnimatedValueView(value: currentPrice, changePercent: 0.025, label: "Price")
    .animation(.spring(duration: 0.8), value: currentPrice)

Part 4: Animation Types

Timing Curve Animations

Timing curve animations use bezier curves to control the speed of animation over time.

Built-in presets

.animation(.linear)          // Constant speed
.animation(.easeIn)          // Starts slow, ends fast
.animation(.easeOut)         // Starts fast, ends slow
.animation(.easeInOut)       // Slow start and end, fast middle

Custom timing curves

let customCurve = UnitCurve(
    startControlPoint: CGPoint(x: 0.2, y: 0),
    endControlPoint: CGPoint(x: 0.8, y: 1)
)

.animation(.timingCurve(customCurve, duration: 0.5))

Duration

All timing curve animations accept an optional duration:

.animation(.easeInOut(duration: 0.3))
.animation(.linear(duration: 1.0))

Default: 0.35 seconds

Spring Animations

Spring animations use physics simulation to create natural, organic motion.

Built-in presets

.animation(.smooth)     // No bounce (default since iOS 17)
.animation(.snappy)     // Small amount of bounce
.animation(.bouncy)     // Larger amount of bounce

Custom springs

.animation(.spring(duration: 0.6, bounce: 0.3))

Parameters

• duration — Perceived animation duration
• bounce — Amount of bounce (0 = no bounce, 1 = very bouncy)

Much more intuitive than traditional spring parameters (mass, stiffness, damping).

Higher-Order Animations

Modify base animations to create complex effects.

Delay

.animation(.spring.delay(0.5))

Waits 0.5 seconds before starting the animation.

Repeat

.animation(.easeInOut.repeatCount(3, autoreverses: true))
.animation(.linear.repeatForever(autoreverses: false))

Repeats the animation multiple times or infinitely.

Speed

.animation(.spring.speed(2.0))  // 2x faster
.animation(.spring.speed(0.5))  // 2x slower

Multiplies the animation speed.

Default Animation Changes (iOS 17+)

Before iOS 17

withAnimation {
    // Used timing curve by default
}

iOS 17+

withAnimation {
    // Uses .smooth spring by default
}

Why the change: Spring animations feel more natural and preserve velocity when interrupted.

Recommendation: Embrace springs. They make your UI feel more responsive and polished.

Part 5: Transaction System

withAnimation

The most common way to trigger an animation.

Button("Scale Up") {
    withAnimation(.spring) {
        scale = 1.5
    }
}

How it works

1. withAnimation opens a transaction
2. Sets the animation in the transaction dictionary
3. Executes the closure (state changes)
4. Transaction propagates down the view hierarchy
5. Animatable attributes check for animation and interpolate

Explicit animation

withAnimation(.spring(duration: 0.6, bounce: 0.4)) {
    isExpanded.toggle()
}

No animation

withAnimation(nil) {
    // Changes happen immediately, no animation
    resetState()
}

animation() View Modifier

Apply animations to specific values within a view.

Basic usage

Circle()
    .fill(isActive ? .blue : .gray)
    .animation(.spring, value: isActive)

How it works: Animation only applies when isActive changes. Other state changes won’t trigger this animation.

Multiple animations on same view

Circle()
    .scaleEffect(scale)
    .animation(.bouncy, value: scale)
    .opacity(opacity)
    .animation(.easeInOut, value: opacity)

Different animations for different properties.

Scoped Animations (iOS 17+)

Narrowly scope animations to specific animatable attributes.

Problem with old approach

struct AvatarView: View {
    var selected: Bool

    var body: some View {
        Image("avatar")
            .scaleEffect(selected ? 1.5 : 1.0)
            .animation(.spring, value: selected)
            // ⚠️ If image also changes when selected changes,
            //    image transition gets animated too (accidental)
    }
}

Solution: Scoped animation

struct AvatarView: View {
    var selected: Bool

    var body: some View {
        Image("avatar")
            .animation(.spring, value: selected) {
                $0.scaleEffect(selected ? 1.5 : 1.0)
            }
            // ✅ Only scaleEffect animates, image transition doesn't
    }
}

How it works

• Animation only applies to attributes in the closure
• Other attributes are unaffected
• Prevents accidental animations

Custom Transaction Keys

Define custom TransactionKey types to propagate context through the transaction system. Use withTransaction to set values and .transaction modifier to read them. This enables applying different animations based on how a state change was triggered (tap vs programmatic).

Part 6: Advanced Topics

CustomAnimation Protocol

Implement your own animation algorithms.

protocol CustomAnimation {
    // Calculate current value
    func animate<V: VectorArithmetic>(
        value: V,
        time: TimeInterval,
        context: inout AnimationContext<V>
    ) -> V?

    // Optional: Should this animation merge with previous?
    func shouldMerge<V>(previous: Animation, value: V, time: TimeInterval, context: inout AnimationContext<V>) -> Bool

    // Optional: Current velocity
    func velocity<V: VectorArithmetic>(
        value: V,
        time: TimeInterval,
        context: AnimationContext<V>
    ) -> V?
}

Example: Linear timing curve

struct LinearAnimation: CustomAnimation {
    let duration: TimeInterval

    func animate<V: VectorArithmetic>(
        value: V,              // Delta vector: target - current
        time: TimeInterval,
        context: inout AnimationContext<V>
    ) -> V? {
        if time >= duration { return nil }
        return value.scaled(by: time / duration)
    }
}

Critical understanding: value is the delta vector (target – current), not the target. Return nil when done. SwiftUI adds the scaled delta to the current value automatically.

Animation Merging Behavior

What happens when a new animation starts before the previous one finishes?

Timing curve animations (default: don’t merge)

func shouldMerge(...) -> Bool {
    return false // Default implementation
}

Behavior: Both animations run together, results are combined additively.

Example

• First tap: animate 1.0 → 1.5 (running)
• Second tap (before finish): animate 1.5 → 1.0
• Result: Both animations run, values combine

Spring animations (merge and retarget)

func shouldMerge(...) -> Bool {
    return true // Springs override this
}

Behavior: New animation incorporates state of previous animation, preserving velocity.

Example

• First tap: animate 1.0 → 1.5 with velocity V
• Second tap (before finish): retarget to 1.0, preserving current velocity V
• Result: Smooth transition, no sudden velocity change

Why springs feel more natural: They preserve momentum when interrupted.

Part 7: Multi-Step Animations (iOS 17+)

PhaseAnimator

Cycles through a sequence of phases, applying different modifiers at each phase. Each phase transition is independently animated.

PhaseAnimator([false, true]) { phase in
    Image(systemName: "star.fill")
        .scaleEffect(phase ? 1.5 : 1.0)
        .opacity(phase ? 1.0 : 0.5)
        .rotationEffect(.degrees(phase ? 360 : 0))
} animation: { phase in
    phase ? .spring(duration: 0.8, bounce: 0.3) : .easeInOut(duration: 0.4)
}

How it works: Begins at first phase, animates to second, then loops. The animation closure returns the animation used to transition INTO that phase. Phases can be any Equatable type — use an enum for complex multi-step sequences:

enum PulsePhase: CaseIterable { case idle, expand, contract }

PhaseAnimator(PulsePhase.allCases) { phase in
    Circle()
        .scaleEffect(phase == .expand ? 1.3 : phase == .contract ? 0.9 : 1.0)
}

Trigger: Add a trigger parameter to run the animation only when a value changes (instead of looping continuously).

KeyframeAnimator

Provides per-property keyframe tracks for precise, timeline-based animations. More control than PhaseAnimator.

struct AnimationValues {
    var scale: Double = 1.0
    var rotation: Angle = .zero
    var yOffset: Double = 0
}

KeyframeAnimator(initialValue: AnimationValues()) { values in
    Image(systemName: "heart.fill")
        .scaleEffect(values.scale)
        .rotationEffect(values.rotation)
        .offset(y: values.yOffset)
} keyframes: { _ in
    KeyframeTrack(\.scale) {
        SpringKeyframe(1.5, duration: 0.3)
        SpringKeyframe(1.0, duration: 0.3)
    }
    KeyframeTrack(\.rotation) {
        LinearKeyframe(.degrees(15), duration: 0.15)
        LinearKeyframe(.degrees(-15), duration: 0.3)
        LinearKeyframe(.zero, duration: 0.15)
    }
    KeyframeTrack(\.yOffset) {
        CubicKeyframe(-20, duration: 0.3)
        CubicKeyframe(0, duration: 0.3)
    }
}

Keyframe types: LinearKeyframe (constant velocity), SpringKeyframe (spring physics), CubicKeyframe (bezier curves), MoveKeyframe (instant jump, no interpolation).

vs PhaseAnimator: Use PhaseAnimator for simple state cycling. Use KeyframeAnimator when different properties need independent timing.

.transition()

Defines how a view animates when inserted/removed from the view hierarchy.

if showDetail {
    DetailView()
        .transition(.slide)                          // Slide in/out
        .transition(.scale.combined(with: .opacity)) // Combine transitions
        .transition(.move(edge: .bottom))            // Move from edge
        .transition(.asymmetric(                     // Different in/out
            insertion: .scale.combined(with: .opacity),
            removal: .opacity
        ))
}

Requires animation context — wrap the state change in withAnimation or use .animation() modifier. Without animation, the view appears/disappears instantly.

matchedGeometryEffect

Smoothly animate a view’s frame between two positions in the hierarchy. Commonly used for hero transitions and shared element animations.

@Namespace private var animation

// Source
if !isExpanded {
    RoundedRectangle(cornerRadius: 10)
        .matchedGeometryEffect(id: "card", in: animation)
        .frame(width: 100, height: 100)
}

// Destination
if isExpanded {
    RoundedRectangle(cornerRadius: 20)
        .matchedGeometryEffect(id: "card", in: animation)
        .frame(width: 300, height: 400)
}

Key rules: Same id + same Namespace = matched pair. Only one view with a given ID should be isSource: true (default) at a time. Wrap state change in withAnimation for smooth interpolation.

contentTransition

Animates changes to text and symbol content within a view (iOS 16+).

Text(value, format: .number)
    .contentTransition(.numericText(countsDown: value < previous))

Image(systemName: isFavorite ? "heart.fill" : "heart")
    .contentTransition(.symbolEffect(.replace))

Part 8: Zoom Transitions (iOS 18+)

Overview

iOS 18 introduces the zoom transition, where a tapped cell morphs into the incoming view. This transition is continuously interactive—users can grab and drag the view during or after the transition begins.

Key benefit In parts of your app where you transition from a large cell, zoom transitions increase visual continuity by keeping the same UI elements on screen across the transition.

SwiftUI Implementation

Two steps to adopt zoom transitions:

Step 1: Declare the transition style on the destination

NavigationLink {
    BraceletEditor(bracelet)
        .navigationTransition(.zoom(sourceID: bracelet.id, in: namespace))
} label: {
    BraceletPreview(bracelet)
}

Step 2: Mark the source view

BraceletPreview(bracelet)
    .matchedTransitionSource(id: bracelet.id, in: namespace)

Complete example

struct BraceletListView: View {
    @Namespace private var braceletList
    let bracelets: [Bracelet]

    var body: some View {
        NavigationStack {
            ScrollView {
                LazyVGrid(columns: [GridItem(.adaptive(minimum: 150))]) {
                    ForEach(bracelets) { bracelet in
                        NavigationLink {
                            BraceletEditor(bracelet: bracelet)
                                .navigationTransition(
                                    .zoom(sourceID: bracelet.id, in: braceletList)
                                )
                        } label: {
                            BraceletPreview(bracelet: bracelet)
                        }
                        .matchedTransitionSource(id: bracelet.id, in: braceletList)
                    }
                }
            }
        }
    }
}

UIKit Implementation

Set preferredTransition = .zoom { context in ... } on the pushed view controller. The closure returns the source view and is called on both zoom in and zoom out — capture a stable identifier (model object), not a view directly.

Presentations

Zoom transitions also work with fullScreenCover and sheet:

.fullScreenCover(item: $selectedBracelet) { bracelet in
    BraceletEditor(bracelet: bracelet)
        .navigationTransition(.zoom(sourceID: bracelet.id, in: namespace))
}

Styling the Source View

.matchedTransitionSource(id: bracelet.id, in: namespace) { source in
    source.cornerRadius(8.0).shadow(radius: 4)
}

Fluid Transition Lifecycle

Push transitions cannot be cancelled — when interrupted, they convert to pop transitions. The view controller always reaches the Appeared state. Don’t guard against overlapping transitions; let the system handle them.

Part 9: UIKit/AppKit Animation Bridging (iOS 18+)

Overview

iOS 18 enables using SwiftUI Animation types to animate UIKit and AppKit views. This provides access to the full suite of SwiftUI animations, including custom animations.

Basic Usage

// Old way
UIView.animate(withDuration: 0.5, delay: 0,
               usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5) {
    bead.center = endOfBracelet
}

// New way: Use SwiftUI Animation type
UIView.animate(.spring(duration: 0.5)) {
    bead.center = endOfBracelet
}

All SwiftUI animations work: .linear, .easeIn/Out, .spring, .smooth, .snappy, .bouncy, .repeatForever(), and custom animations.

Architecture note: Unlike old UIKit APIs, no CAAnimation is generated — presentation values are animated directly.

Part 10: UIViewRepresentable Animation Bridging (iOS 18+)

The Problem

When wrapping UIKit views in SwiftUI, animations don’t automatically bridge:

struct BeadBoxWrapper: UIViewRepresentable {
    @Binding var isOpen: Bool

    func updateUIView(_ box: BeadBox, context: Context) {
        // ❌ Animation on binding doesn't affect UIKit
        box.lid.center.y = isOpen ? -100 : 100
    }
}

// Usage
BeadBoxWrapper(isOpen: $isOpen)
    .animation(.spring, value: isOpen)  // No effect on UIKit view

The Solution: context.animate()

Use context.animate() to bridge SwiftUI animations:

struct BeadBoxWrapper: UIViewRepresentable {
    @Binding var isOpen: Bool

    func makeUIView(context: Context) -> BeadBox {
        BeadBox()
    }

    func updateUIView(_ box: BeadBox, context: Context) {
        // ✅ Bridges animation from Transaction to UIKit
        context.animate {
            box.lid.center.y = isOpen ? -100 : 100
        }
    }
}

How It Works

1. SwiftUI stores animation info in the current Transaction
2. context.animate() reads the Transaction’s animation
3. Applies that animation to UIView changes in the closure
4. If no animation in Transaction, changes happen immediately (no animation)

Key Behavior

context.animate {
    // Changes here
} completion: {
    // Called when animation completes
    // If not animated, called immediately inline
}

Works whether animated or not — safe to always use this pattern.

Perfect Synchronization

A single animation running across SwiftUI Views and UIViews runs perfectly in sync. This enables seamless mixed hierarchies.

Part 11: Gesture-Driven Animations (iOS 18+)

Automatic Velocity Preservation

SwiftUI animations automatically preserve velocity through animation merging — no manual velocity calculation needed:

// UIKit with SwiftUI animations
func handlePan(_ gesture: UIPanGestureRecognizer) {
    switch gesture.state {
    case .changed:
        UIView.animate(.interactiveSpring) {
            bead.center = gesture.location(in: view)
        }
    case .ended:
        UIView.animate(.spring) {  // Inherits velocity automatically
            bead.center = endOfBracelet
        }
    default: break
    }
}

// Pure SwiftUI equivalent
DragGesture()
    .onChanged { value in
        withAnimation(.interactiveSpring) { position = value.location }
    }
    .onEnded { _ in
        withAnimation(.spring) { position = targetPosition }
    }

Each .interactiveSpring retargets the previous animation, and the final .spring inherits the accumulated velocity for smooth deceleration.

Troubleshooting

Property Not Animating

Check in order:

1. Type conforms to VectorArithmetic? — Int can’t animate; use Double/Float
2. Animation modifier present? — Need .animation(.spring, value: x) or withAnimation
3. Correct value tracked? — .animation(.spring, value: progress) not .animation(.spring, value: title)
4. View conforms to Animatable? — Custom views need @Animatable (iOS 26+) or manual animatableData

Animation Stuttering

Custom Animatable conformance calls body every frame on main thread. Use built-in effects (.opacity(), .scaleEffect()) when possible — they run off-main-thread. Profile with Instruments for complex cases.

Unexpected Animation Merging

Spring animations merge by default, preserving velocity. Use timing curve animations (.easeInOut) if you don’t want merging behavior. See Animation Merging Behavior section above.

Resources

WWDC: 2023-10156, 2023-10157, 2023-10158, 2024-10145, 2025-256

Docs: /swiftui/animatable, /swiftui/animation, /swiftui/vectorarithmetic, /swiftui/transaction, /swiftui/view/navigationtransition(:), /swiftui/view/matchedtransitionsource(id:in:configuration:), /uikit/uiview/animate(:changes:completion:)

Skills: axiom-swiftui-26-ref, axiom-swiftui-nav-ref, axiom-swiftui-performance, axiom-swiftui-debugging, axiom-sf-symbols-ref