LayrzProgressBar

A standardized linear progress bar with determinate and indeterminate modes.

Metadata Predecessor: None — no direct ThemedProgressBar exists in layrz_theme Phase: M6 (pulled forward as an M4/M5 prerequisite) Domain: Feedback Primitive: CustomPaint (no Material LinearProgressIndicator) Status: Merged · Review required.

Overview

LayrzProgressBar renders a rounded-capsule track with a filled indicator, in one of two modes selected entirely by whether value is null:

Determinate (value non-null, [0.0, 1.0]): a filled bar growing from the leading edge as value increases — 1.0 is a full bar.
Indeterminate (value == null): a capsule that sweeps back and forth across the track, looping for as long as the widget is mounted.

// Determinate — upload progress
LayrzProgressBar(value: 0.42, semanticLabel: 'Upload progress')

// Indeterminate — unknown-duration operation
LayrzProgressBar(semanticLabel: 'Loading')

null always means indeterminate, never zero progress — a caller wanting to show "no progress yet" passes 0.0 explicitly.

Determinate direction is the opposite of `LayrzButtonIndicator`

LayrzButtonIndicator's internal determinate mode depletes from full to empty (correct for a button countdown). LayrzProgressBar is the opposite: it fills from empty to full as value rises. This is a deliberate divergence, not an inconsistency — the two components serve different semantics and neither replicates the other's direction.

Non-goals

This widget is display-only — it is not interactive. A draggable variant is LayrzSlider's responsibility, not this widget's. It also has no circular/ring variant — a future LayrzProgressRing would be a separate component, not an option on this one.

Colors follow the `LayrzChipType` semantic convention

LayrzProgressBarType (info / success / warning / danger / context / custom) mirrors LayrzChipType's vocabulary exactly, rather than inventing a second semantic-color enum. When type is custom, the explicit color parameter is honored instead of a token color, falling back to tokens.colors.primary.shade500 if both are unset.

Accessibility

The bar wraps its content in a live-region Semantics node. semanticLabel supplies the human-readable description (e.g. 'Upload progress'); when null, a generic label is used — 'Progress' for determinate mode, 'Loading' for indeterminate. The percentage (determinate) or busy state (indeterminate) is always announced in addition to the label, never in its place.

Reduced motion (MediaQuery.disableAnimationsOf) freezes the indeterminate sweep at its start position instead of looping — the sweep controller is torn down entirely rather than merely left unstarted while reduce-motion is active, and is recreated the next time it's needed.

API