Spinner

Spinner — a shader-driven circular-arc loading indicator.
Uses the same per-slot uniform-buffer pipeline as
ProgressBar::indeterminate (an
AnimatedQuadKind variant), so per-frame cost is one
queue.write_buffer(64 B) + draw_indexed — the widget's paint()
does not re-run between frames and there's no signal-dirty-mark
cascade.
#![allow(unused)] fn main() { use teksilo_widgets::Spinner; use teksilo_tokens::TextRole; use teksilo_i18n::lit; let _s = Spinner::new(24.0) .color(TextRole::Secondary) .label(lit!("Loading")); }
Defaults match the typical CSS spinner: a quarter-circle (90°) arc rotating clockwise from the top, completing one full rotation every 900 ms.
Honours prefers-reduced-motion: registers no animated quad and
falls back to a static three-quarter arc — the indicator is still
visible (so the user can tell the surface is busy) but doesn't
rotate.
Builder methods at a glance
period, arc_fraction, stroke_fraction, color, label
API reference
📖 Full rustdoc API for this module
pub struct Spinner
A circular-arc loading indicator driven by a GPU shader quad.
Decorative — pair with .label to give screen readers
context. Honours prefers-reduced-motion by falling back to a static
three-quarter arc.
#![allow(unused)] fn main() { pub struct Spinner { /* fields */ } }
Methods
pub fn new(size: f32) -> Self
Construct a spinner of the given square edge length (logical pixels). Use small sizes (16–24) for inline spinners and larger (32–64) for full-content placeholders.
pub fn period(mut self, period: Duration) -> Self
Override the rotation period. Default: 900 ms (one full rotation per period).
pub fn arc_fraction(mut self, arc_fraction: f32) -> Self
Override the arc length as a fraction of the full circle. Default: 0.25 (a quarter-circle "comet tail" arc).
pub fn stroke_fraction(mut self, stroke_fraction: f32) -> Self
Override the stroke thickness as a fraction of the spinner's edge length. Default: 0.12 (so a 24-px spinner has a ~3-px stroke).
pub fn color(mut self, color: impl Into<ColorProp>) -> Self
Override the arc colour. Default: TextRole::Secondary so the
spinner picks up theme-aware text-tier styling.
pub fn label(mut self, text: impl Into<LocalizedString>) -> Self
Accessible name (e.g. "Loading", "Uploading file"). Without this, screen readers announce a bare "progress indicator" with no context.