Struct AnimationController 

pub struct AnimationController { /* private fields */ }

A 0.0..=1.0 value driven by a duration + Curve or a Spring fling.

Plain data + math (see the module contract): a widget advances it during paint and re-requests a frame while advance returns true. forward/reverse/animate_to settle as Completed/Dismissed; repeat never completes; a fling settles at 1.0 (non-negative velocity) or 0.0.

Overshoot (spring-driven only)

A fling is not clamped in flight: an under-damped SpringDesc (M3’s spatial presets use damping_ratio: 0.9) overshoots on purpose, then lands exactly on the target. Use value_clamped for a bounded read.

Implementations

impl AnimationController

pub fn new(duration: Duration) -> Self

Create an idle controller at 0.0 with the given default duration and Curve::Linear.

pub fn with_curve(self, curve: Curve) -> Self

Set the easing curve applied to duration-driven motion (builder-style).

pub fn value(&self) -> f64

The current value: within 0.0..=1.0 for duration motion, but a spring fling may transiently leave that range (see the type docs’ Overshoot section); see value_clamped.

pub fn value_clamped(&self) -> f64

value clamped to 0.0..=1.0; differs from it only while a fling overshoots.

pub fn status(&self) -> AnimationStatus

The current lifecycle status.

pub fn is_animating(&self) -> bool

Whether a motion is in progress (the next advance makes progress).

pub fn forward(&mut self)

Animate forward to 1.0 over the controller’s duration.

pub fn reverse(&mut self)

Animate reverse to 0.0 over the controller’s duration.

pub fn animate_to(&mut self, target: f64)

Animate from the current value to target (clamped to 0.0..=1.0) over the controller’s duration.

pub fn repeat(&mut self)

Loop 0.0→1.0 (eased) indefinitely with a period of the controller’s duration. advance always returns true for a repeat.

pub fn fling(&mut self, velocity: f64, spring: SpringDesc)

Start a spring fling from the current value with initial velocity (value units per second), settling at 1.0 for a non-negative velocity, else 0.0. The value is not clamped in flight (see the type docs’ Overshoot section).

pub fn stop(&mut self)

Halt any in-progress motion, leaving the value where it is and the status AnimationStatus::Idle.

pub fn advance(&mut self, now: FrameTime) -> bool

Advance to frame time now, returning whether it is still animating (the caller must then request another frame).

The delta uses FrameTime::saturating_sub, so a repeated or out-of-order timestamp yields a zero delta, never a panic or NaN. The first advance after starting a motion only seeds the clock.

Trait Implementations

impl Clone for AnimationController

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for AnimationController

impl Debug for AnimationController

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

Formats the value using the given formatter.