Motion

ThemeKit components animate micro state changes — a press scale, a selection slide, a value tick — and nothing showy. Every bit of that motion is switchable, at two scopes, and the system Reduce Motion setting always overrides both.

Turning it off

// Theme-wide — one switch at the app root disables motion everywhere downstream.
RootView()
    .microAnimations(false)

// Per-component — override just one component (or one subtree).
PrimaryButton("Still") { … }
    .microAnimations(false)

microAnimations is a SwiftUI EnvironmentValues flag (default true) read by the shared button styles and by individual components. Because it’s environment-based, the same modifier does both jobs: set it high for a global switch, set it low to override a branch. The effective rule is:

animate  ==  microAnimations  &&  !accessibilityReduceMotion

So a Reduce-Motion user never sees motion regardless of the flag, and you can still force a specific component still even when motion is on globally.

Using it in a component

@Environment(\.microAnimations) private var micro
@Environment(\.accessibilityReduceMotion) private var reduceMotion

someView
    .animation(
        MicroMotion.animation(.fast, enabled: micro, reduceMotion: reduceMotion),
        value: state
    )

MicroMotion.animation(_:enabled:reduceMotion:) returns nil when motion is off, and a nil animation makes the state change apply instantly (no motion) — so the UI stays fully functional, it just stops moving.

For a tappable surface that isn’t already a ThemeKit ButtonStyle, the gated press-scale helper:

myView.microPressScale(isPressed)   // 0.97 by default, snaps when motion is off

Design rules (what “micro” means here)

• Durations come from the Motion tokens — instant (0.10s) for press, fast (0.20s) for state/selection. Nothing slower for interaction feedback.
• Magnitudes stay small: ~0.97 scale, opacity, 2–4 pt offset. No bounce, no overshoot, no attention-grabbing springs.
• Static atoms (Divider, Kbd, InlineText) get no animation — motion is reserved for interactive and stateful components.

Reduce Motion is part of ThemeKit’s broader accessibility story.