Struct SystemAnimations 

#[repr(C)]
pub struct SystemAnimations {
    pub caret_tween: CaretTweenCallback,
    pub selection_tween: SelectionTweenCallback,
    pub caret_tween_data: RefAny,
    pub selection_tween_data: RefAny,
    pub scroll_physics: OptionScrollPhysics,
    pub caret_tween_duration_ms: u32,
    pub selection_tween_duration_ms: u32,
    pub focus_ring_duration_ms: u32,
    pub caret_scroll_glide: bool,
}

Configuration of the SYSTEM-driven animations: physics-based scrolling and the caret / selection tweens. Lives on AppConfig so a platform or application can tune the feel without rebuilding azul.

The scroll physics override is applied ON TOP of the platform-discovered SystemStyle at App::create time (None keeps the per-platform preset). The tween slots always apply; set a duration to 0 to disable that tween (the caret / selection then jumps, the classic behavior).

Fields

caret_tween: CaretTweenCallback

The caret tween MATH: called every animation frame with the past / current caret rectangles and linear progress t; returns the rectangle to render. Default: ease-out cubic lerp.

selection_tween: SelectionTweenCallback

The selection tween MATH: called every animation frame with the past / current selection band rectangles and linear progress t; returns the rectangles to render (must match the current count). Default: ease-out cubic lerp, rectangles paired by index.

caret_tween_data: RefAny

User data passed to caret_tween on every invocation.

selection_tween_data: RefAny

User data passed to selection_tween on every invocation.

scroll_physics: OptionScrollPhysics

Overrides SystemStyle.scroll_physics (momentum, overscroll / rubber-band, wheel-vs-trackpad curves). None = platform default.

caret_tween_duration_ms: u32

Duration of the caret-move tween in ms. 0 disables the tween. While the tween runs, caret blinking is suppressed (caret stays solid while it moves).

selection_tween_duration_ms: u32

Duration of the selection tween in ms. 0 disables the tween.

focus_ring_duration_ms: u32

Focus-ring glide duration in ms (ledger #29). 0 (the DEFAULT) disables the ring entirely — no visual change for existing apps; an app that opts in gets a focus outline that GLIDES between focused elements using the caret_tween interpolator (the ring is suppressed while a text-editing session owns focus — there the caret is the indicator).

caret_scroll_glide: bool

Whether “scroll the caret into view” glides via the scroll-physics spring (true, the Word feel) or jumps instantly (false — also what Self::disabled sets, keeping e2e screenshots deterministic).

Implementations

impl SystemAnimations

pub fn disabled() -> Self

All system animations disabled: no scroll-physics override, tween durations 0 (caret / selection jump). Test drivers and deterministic harnesses use this so screenshots never catch geometry mid-glide.

Trait Implementations

impl Clone for SystemAnimations

fn clone(&self) -> SystemAnimations

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SystemAnimations

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for SystemAnimations

fn default() -> Self

Returns the “default value” for a type.