Enum ScrollPhysics 

pub enum ScrollPhysics {
    Exponential {
        decay_per_ms: f32,
    },
    FrictionSpline {
        friction: f32,
        pixels_per_inch: f32,
    },
}

How free scrolling decelerates after a fling.

This models deceleration only. Boundary behavior — bouncing, edge glow, clamping — is the scroll container’s policy: the container is the one that knows its extents.

Variants

Exponential

Exponential velocity decay, the UIScrollView model: velocity(t) = v₀ · decay_per_msᵐˢ.

Fields

decay_per_ms: f32

Per-millisecond velocity decay factor. UIScrollView’s normal deceleration rate is 0.998.

FrictionSpline

The friction spline of Android’s OverScroller: fling duration and distance follow a logarithmic deceleration law, and progress along the fling follows a cubic-Bezier ease-out curve. Transcribed from AOSP’s SplineOverScroller (Apache-2.0).

Fields

friction: f32

The scroll friction coefficient; ViewConfiguration.getScrollFriction() is 0.015 on Android.

pixels_per_inch: f32

Pixels per physical inch of the display, in the coordinate space the fling runs in. Android folds display density into its deceleration coefficient, so the same finger speed flings further in pixels on a denser screen.

Implementations

impl ScrollPhysics

pub fn ios() -> ScrollPhysics

iOS scroll feel: UIScrollView’s normal deceleration rate.

pub fn android() -> ScrollPhysics

Android scroll feel: OverScroller with stock friction, at Android’s nominal density of 160 density-independent pixels per inch — the right pairing when fling distances are in logical pixels. Platforms that fling in physical pixels, or know the display’s true density in their logical space, should construct ScrollPhysics::FrictionSpline directly.

Trait Implementations

impl Clone for ScrollPhysics

fn clone(&self) -> ScrollPhysics

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ScrollPhysics

impl Debug for ScrollPhysics

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

Formats the value using the given formatter.

impl PartialEq for ScrollPhysics

fn eq(&self, other: &ScrollPhysics) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ScrollPhysics