Struct ScrollMomentum 

pub struct ScrollMomentum { /* private fields */ }

Deterministic single-axis momentum used by virtualized collection widgets. Wheel input moves immediately; line-wheel impulses additionally feed this decay curve so detented wheels can traverse long collections without requiring one event per row.

Implementations

impl ScrollMomentum

pub fn new() -> ScrollMomentum

pub fn push(&mut self, delta: f64) -> f64

Add a logical-pixel wheel impulse. Return the immediate delta so the caller can apply it in the same input frame.

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

Continue from a content-space drag velocity after pointer release. The velocity is clamped to the same ceiling as accumulated wheel impulses, keeping a bad timestamp or synthetic pointer from launching the viewport an unbounded distance.

pub fn tick(&mut self, elapsed: Duration) -> f64

Advance the curve and return the logical-pixel displacement.

pub fn stop(&mut self)

pub fn wheel( &mut self, delta: &MouseScrollDelta, phase: TouchPhase, reduce_motion: bool, ) -> WheelStep

Classify one vertical wheel event. Line (detented) wheels accelerate through Self::push; pixel (touchpad, touchscreen) deltas track the finger exactly and, when the gesture’s Ended phase arrives while still moving, continue as a fling. reduce_motion keeps every movement 1:1 with the input.

pub fn wheel_applied(&mut self, delta: f64, moved: bool)

Report whether the WheelStep::Scroll delta moved the content. A refused delta (at an edge) stops momentum and forgets the gesture so an outer scroll region can take it over, fling included.

pub fn is_active(&self) -> bool

Trait Implementations

impl Clone for ScrollMomentum

fn clone(&self) -> ScrollMomentum

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ScrollMomentum

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

Formats the value using the given formatter.

impl Default for ScrollMomentum

fn default() -> ScrollMomentum

Returns the “default value” for a type.