Enum ScrollPhysics 

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

How a fling slows down after the finger lifts.

This models deceleration only. Boundary behavior, such as bouncing, edge glow and clamping, belongs to the scroll container, which knows its extents. Use ScrollPhysics::ios or ScrollPhysics::android for the platform feel.

Variants

Exponential

Exponential velocity decay, the UIScrollView model: velocity(t) = v₀ · decay_per_msᵗ, where t is elapsed milliseconds.

Fields

decay_per_ms: f32

The velocity multiplier per millisecond. 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() -> Self

Returns the iOS feel: exponential decay at UIScrollView’s normal rate of 0.998 per millisecond. This is the default in GestureTuning.

pub fn android() -> Self

Returns the Android feel: OverScroller with its stock friction of 0.015 at 160 pixels per inch, Android’s nominal density.

Use this when fling distances are in logical pixels. A platform that flings in physical pixels, or that knows the display’s real density, should build ScrollPhysics::FrictionSpline with its own pixels_per_inch instead.

Trait Implementations

impl Clone for ScrollPhysics

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 ScrollPhysics

impl Debug for ScrollPhysics

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

Formats the value using the given formatter.

impl PartialEq for ScrollPhysics

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ScrollPhysics