Struct ScrollBehavior

Source

pub struct ScrollBehavior {
    pub axes: ScrollAxes,
    pub line_px: f32,
}

Expand description

Wheel normalization and per-widget scroll tuning.

§Examples

use ailloli_ui_core::{ScrollAxes, ScrollBehavior};
let behavior = ScrollBehavior::new(ScrollAxes::VERTICAL);
assert_eq!(behavior.line_px, ScrollBehavior::DEFAULT_LINE_PX);

Fields§

§axes: ScrollAxes

Axes that receive normalized wheel motion.

§line_px: f32

Logical pixels represented by one platform line unit.

Implementations§

Source §

impl ScrollBehavior

Source

pub const DEFAULT_LINE_PX: f32 = 48f32

Default logical distance of one wheel line: 48 pixels.

§Examples

use ailloli_ui_core::ScrollBehavior;
assert_eq!(ScrollBehavior::DEFAULT_LINE_PX, 48.0);

Source

pub fn new(axes: ScrollAxes) -> Self

Creates behavior for axes using Self::DEFAULT_LINE_PX.

§Examples

use ailloli_ui_core::{ScrollAxes, ScrollBehavior};
assert_eq!(ScrollBehavior::new(ScrollAxes::BOTH).axes, ScrollAxes::BOTH);

Source

pub fn with_line_px(self, line_px: f32) -> Self

Sets the line distance, clamped to at least one logical pixel.

NaN and negative infinity become 1.0 through floating-point max semantics; positive infinity remains infinite.

§Examples

use ailloli_ui_core::{ScrollAxes, ScrollBehavior};
assert_eq!(ScrollBehavior::new(ScrollAxes::BOTH).with_line_px(0.0).line_px, 1.0);

Source

pub fn wheel_delta(self, delta: WheelDelta) -> Offset

Converts a platform wheel delta to a filtered logical content offset.

Line deltas are scaled by Self::line_px; pixel deltas are already in logical pixels. Both forms are negated so a positive wheel delta moves the viewed content toward its origin.

§Examples

use ailloli_ui_core::{Offset, ScrollAxes, ScrollBehavior};
use ailloli_ui_core::event::WheelDelta;
let delta = ScrollBehavior::new(ScrollAxes::VERTICAL).wheel_delta(WheelDelta::LineDelta { x: 1.0, y: -2.0 });
assert_eq!(delta, Offset::new(0.0, 96.0));

Source

pub fn wheel_delta_with_modifiers( self, delta: WheelDelta, modifiers: Modifiers, ) -> Offset

Converts wheel input while applying the framework’s Shift-axis policy.

Line values use Self::line_px and pixel values are already logical. Native horizontal movement is preserved. When Shift is held and the horizontal axis is enabled, normalized vertical movement is added to X and removed from Y. Vertical-only surfaces therefore keep scrolling vertically under Shift. Non-finite components become zero.

The provider’s precise flag is intentionally absent: line-versus-pixel already determines scaling, while precision remains event metadata and does not introduce acceleration.

§Examples

use ailloli_ui_core::{event::{Modifiers, WheelDelta}, Offset, ScrollAxes, ScrollBehavior};
let modifiers = Modifiers { shift: true, ..Modifiers::default() };
let delta = ScrollBehavior::new(ScrollAxes::BOTH).with_line_px(10.0)
    .wheel_delta_with_modifiers(WheelDelta::LineDelta { x: -1.0, y: -2.0 }, modifiers);
assert_eq!(delta, Offset::new(30.0, 0.0));