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ClideMarquee honours reduced motion (MediaQuery.disableAnimations) (T-284)

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The status-bar footer marquee drove a raw Ticker whenever its content
overflowed, ignoring MediaQuery.disableAnimations — unlike the turn indicator
(T-273), which stops on the same flag. Two costs: reduced-motion users still
got the scrolling footer, and the perpetual ticker was the historical
pumpAndSettle-hang culprit (its tests cope by only ever pump()-ing).

Unify on the one mechanism: read disableAnimations in didChangeDependencies
(as running_indicator does) and gate the ticker on it via _syncTicker(). Under
reduced motion the marquee never starts the ticker (stops + resets if running)
and renders the child statically (clipped, no looped copy). Toggling the flag
at runtime starts/stops the scroll.

Tests: reduced-motion marquee does not scroll and pumpAndSettle completes (no
hang); flipping the flag off lets an overflowing marquee scroll again.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
jpmschweitzer
2026-06-08 16:57:25 +02:00
co-authored by Claude Opus 4.8
parent 5241876871
commit d5ec85932d
5 changed files with 104 additions and 4 deletions
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lib/widgets/src/clide_marquee.dart
+27 -4
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@@ -39,6 +39,12 @@ class _ClideMarqueeState extends State<ClideMarquee> with SingleTickerProviderSt
double _offset = 0;
Duration _last = Duration.zero;
/// Honour reduced motion (T-284): the same `MediaQuery.disableAnimations`
/// flag the running indicator gates on (T-273). When set, the marquee never
/// scrolls — it shows the child statically (clipped) — so reduced-motion
/// users get no motion and `pumpAndSettle` isn't wedged by a perpetual ticker.
bool _reduced = false;
bool get _overflow => _contentWidth > _viewportWidth + 0.5;
@override
@@ -47,6 +53,16 @@ class _ClideMarqueeState extends State<ClideMarquee> with SingleTickerProviderSt
WidgetsBinding.instance.addPostFrameCallback((_) => _measure());
}
@override
void didChangeDependencies() {
super.didChangeDependencies();
final reduced = MediaQuery.maybeOf(context)?.disableAnimations ?? false;
if (reduced != _reduced) {
setState(() => _reduced = reduced);
_syncTicker();
}
}
@override
void didUpdateWidget(ClideMarquee old) {
super.didUpdateWidget(old);
@@ -59,10 +75,17 @@ class _ClideMarqueeState extends State<ClideMarquee> with SingleTickerProviderSt
if ((w - _contentWidth).abs() > 0.5) {
setState(() => _contentWidth = w);
}
if (_overflow && !_ticker.isActive) {
_syncTicker();
}
/// Start the scroll ticker only when the content overflows AND motion is
/// allowed; otherwise stop it and reset to the start.
void _syncTicker() {
final shouldRun = _overflow && !_reduced;
if (shouldRun && !_ticker.isActive) {
_last = Duration.zero;
_ticker.start();
} else if (!_overflow && _ticker.isActive) {
} else if (!shouldRun && _ticker.isActive) {
_ticker.stop();
_offset = 0;
if (_scroll.hasClients) _scroll.jumpTo(0);
@@ -70,7 +93,7 @@ class _ClideMarqueeState extends State<ClideMarquee> with SingleTickerProviderSt
}
void _tick(Duration elapsed) {
if (!_overflow || !_scroll.hasClients) return;
if (!_overflow || _reduced || !_scroll.hasClients) return;
final dt = _last == Duration.zero ? 0.0 : (elapsed - _last).inMicroseconds / 1e6;
_last = elapsed;
final span = _contentWidth + widget.gap;
@@ -101,7 +124,7 @@ class _ClideMarqueeState extends State<ClideMarquee> with SingleTickerProviderSt
mainAxisSize: MainAxisSize.min,
children: [
KeyedSubtree(key: _childKey, child: widget.child),
if (_overflow) ...[SizedBox(width: widget.gap), widget.child],
if (_overflow && !_reduced) ...[SizedBox(width: widget.gap), widget.child],
],
),
);