Struct FocusRing 

pub struct FocusRing {
    pub color: [u8; 4],
    pub width: f32,
    pub offset: f32,
    pub radius: f32,
}

Visual properties for a focus ring, consumed by renderers.

Describes the outline drawn around the currently-focused widget. All measurements are in logical pixels.

Fields

color: [u8; 4]

Colour of the ring in RGBA byte order [r, g, b, a].

width: f32

Stroke width in logical pixels.

offset: f32

Outset distance from the widget’s bounding box in logical pixels.

radius: f32

Corner radius of the ring in logical pixels (0.0 = sharp corners).

Implementations

impl FocusRing

pub fn ring_rect( &self, x: f32, y: f32, width: f32, height: f32, ) -> (f32, f32, f32, f32)

Compute the bounding rectangle for the ring given the widget’s bounding box (x, y, width, height) in logical pixels.

Returns (rx, ry, rw, rh) where the ring is outset by self.offset on all sides and the stroke of self.width is applied further outward. This is the rectangle that a renderer should stroke / outline.

Note for renderers

The returned rectangle is the outer boundary of the ring stroke. Renderers should stroke the rectangle inward by self.width / 2.0 to position the stroke centrally on the boundary.

Example

use oxiui_accessibility::FocusRing;

let ring = FocusRing { width: 2.0, offset: 2.0, ..Default::default() };
let (rx, ry, rw, rh) = ring.ring_rect(10.0, 20.0, 100.0, 30.0);
// outset by offset (2) + half width (1) on each side
assert_eq!(rx, 10.0 - 2.0 - 1.0);
assert_eq!(ry, 20.0 - 2.0 - 1.0);
assert_eq!(rw, 100.0 + (2.0 + 1.0) * 2.0);
assert_eq!(rh, 30.0 + (2.0 + 1.0) * 2.0);

pub fn is_visible(&self) -> bool

Returns true when the ring should be rendered (i.e. it has a non-zero stroke width and a non-fully-transparent colour).

Renderers may skip drawing the ring when this returns false.

Example

use oxiui_accessibility::FocusRing;

let visible = FocusRing::default();
assert!(visible.is_visible());

let invisible = FocusRing { color: [0, 0, 0, 0], ..Default::default() };
assert!(!invisible.is_visible());

Trait Implementations

impl Clone for FocusRing

fn clone(&self) -> FocusRing

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FocusRing

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

Formats the value using the given formatter.

impl Default for FocusRing

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for FocusRing

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for FocusRing