Struct RotaryScrollEvent 

pub struct RotaryScrollEvent {
    pub vertical_scroll_pixels: f32,
    pub horizontal_scroll_pixels: f32,
    pub uptime_millis: u64,
}

Re-export the UI crate so applications can depend on a single crate. A rotary scroll event produced by a Wear OS crown or rotating bezel.

Field-for-field equivalent to Compose’s androidx.compose.ui.input.rotary.RotaryScrollEvent. The scroll amounts are in pixels, not detents: the platform layer has already multiplied the raw axis value by the system scroll factor.

This type is Copy and contains no heap data, so dispatching one allocates nothing.

Fields

vertical_scroll_pixels: f32

How far to scroll (in pixels) in a container that scrolls vertically.

Negative when the user turned the crown “up”/away (positive AXIS_SCROLL on Android); see the module docs for the derivation.

horizontal_scroll_pixels: f32

How far to scroll (in pixels) in a container that scrolls horizontally.

uptime_millis: u64

Time in milliseconds at which the event occurred. The zero point is platform-dependent (Android’s uptime clock, the process start elsewhere), so only differences between events are meaningful.

Implementations

impl RotaryScrollEvent

pub const fn new( vertical_scroll_pixels: f32, horizontal_scroll_pixels: f32, uptime_millis: u64, ) -> RotaryScrollEvent

Creates a rotary event from scroll amounts that are already in pixels.

pub fn from_detents( detents: f32, vertical_scroll_factor: f32, horizontal_scroll_factor: f32, uptime_millis: u64, ) -> RotaryScrollEvent

Builds a rotary event from a raw Android AXIS_SCROLL value in detents.

detents is the value straight out of AMotionEvent_getAxisValue(event, AMOTION_EVENT_AXIS_SCROLL, 0); the scroll factors are ViewConfiguration.getScaledVerticalScrollFactor() and getScaledHorizontalScrollFactor().

The detent value is negated exactly once, matching Compose (see the module docs), and the same negated value feeds both axes.

pub fn from_wheel_pixels( vertical: f32, horizontal: f32, uptime_millis: u64, ) -> RotaryScrollEvent

Builds a rotary event from a mouse-wheel / trackpad sample already in logical pixels.

The final target for rotary input is a Wear OS crown, but the machines it is developed on have wheels, so every desktop-class host offers its wheel to the rotary handlers first. vertical and horizontal are in the shell’s wheel convention — positive when the content should move down and right, the direction a wheel turned up produces — which is the same physical direction as a positive Android detent. Both are therefore negated exactly once, like from_detents, so a wheel turned up and a crown turned up land on the same negative vertical_scroll_pixels.

Unlike the detent path, a wheel really does have two axes, so each one is carried through on its own rather than fanned out from a single value.

pub fn is_empty(&self) -> bool

Returns true when neither axis carries a usable scroll amount.

Non-finite values (NaN/inf from a misbehaving driver) count as empty so they are dropped at the ingress instead of poisoning scroll offsets.

Trait Implementations

impl Clone for RotaryScrollEvent

fn clone(&self) -> RotaryScrollEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for RotaryScrollEvent

impl Debug for RotaryScrollEvent

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

Formats the value using the given formatter.

impl Default for RotaryScrollEvent

fn default() -> RotaryScrollEvent

Returns the “default value” for a type.

impl PartialEq for RotaryScrollEvent

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for RotaryScrollEvent