Struct VelocityTracker 

pub struct VelocityTracker { /* private fields */ }

A ring of recent (time_ms, position) samples used to estimate the release velocity of a drag for flinging.

Samples older than VELOCITY_WINDOW_MS (relative to the newest) are pruned on record; velocity is a simple delta-over-window estimate (px/s) — enough for v1 fling, without Flutter’s least-squares regression.

Implementations

impl VelocityTracker

pub fn new() -> VelocityTracker

An empty tracker.

pub fn clear(&mut self)

Drop all samples (call on the Down that begins a fresh gesture).

pub fn record(&mut self, time_ms: f64, position: f64)

Record a (time_ms, position) sample, pruning any now older than the trailing window.

pub fn velocity(&self) -> f64

Estimate the current velocity in px/s from the delta across the retained window. Returns 0.0 with fewer than two samples or a zero time span.

pub fn len(&self) -> usize

The number of retained samples (for tests/introspection).

pub fn is_empty(&self) -> bool

Whether the tracker holds no samples.

Trait Implementations

impl Clone for VelocityTracker

fn clone(&self) -> VelocityTracker

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VelocityTracker

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

Formats the value using the given formatter.

impl Default for VelocityTracker

fn default() -> VelocityTracker

Returns the “default value” for a type.