Files
clide/lib/widgets/src/clide_marquee.dart
T
jpmschweitzerandClaude Opus 4.7 478cff6050 add ClidePane primitive + focus-driven status-bar slot
Replace the MessageBus-based pane-context slot with a focus-driven one.
Panes keep their status widget locally; the FocusTracker holds the
focused pane's widget (activeStatusWidget) and ClidePane conveys it to
the shared slot only while its contribution is focused, re-conveying on
change and clearing on blur. The status-bar item just renders
focus.activeStatusWidget, height-clamped and marquee-scrolled when it
overflows. Removes the publish/subscribe race the bus version had.

T-150.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-23 11:23:30 +02:00

113 lines
3.1 KiB
Dart

/// Horizontal marquee (T-150). Shows [child] statically when it fits the
/// available width; when it's wider, scrolls it leftward in a seamless
/// loop (a second copy follows after [gap]). Clips to its box. Used by
/// the status-bar slot so a long pane status doesn't get truncated.
///
/// Own-the-stack: a `Ticker`-driven `SingleChildScrollView`, no package.
library;
import 'package:flutter/scheduler.dart';
import 'package:flutter/widgets.dart';
class ClideMarquee extends StatefulWidget {
const ClideMarquee({
super.key,
required this.child,
this.pxPerSecond = 28,
this.gap = 48,
});
final Widget child;
/// Scroll speed when overflowing.
final double pxPerSecond;
/// Space between the looped copies.
final double gap;
@override
State<ClideMarquee> createState() => _ClideMarqueeState();
}
class _ClideMarqueeState extends State<ClideMarquee> with SingleTickerProviderStateMixin {
final GlobalKey _childKey = GlobalKey();
final ScrollController _scroll = ScrollController();
late final Ticker _ticker = createTicker(_tick);
double _contentWidth = 0;
double _viewportWidth = 0;
double _offset = 0;
Duration _last = Duration.zero;
bool get _overflow => _contentWidth > _viewportWidth + 0.5;
@override
void initState() {
super.initState();
WidgetsBinding.instance.addPostFrameCallback((_) => _measure());
}
@override
void didUpdateWidget(ClideMarquee old) {
super.didUpdateWidget(old);
WidgetsBinding.instance.addPostFrameCallback((_) => _measure());
}
void _measure() {
if (!mounted) return;
final w = _childKey.currentContext?.size?.width ?? 0;
if ((w - _contentWidth).abs() > 0.5) {
setState(() => _contentWidth = w);
}
if (_overflow && !_ticker.isActive) {
_last = Duration.zero;
_ticker.start();
} else if (!_overflow && _ticker.isActive) {
_ticker.stop();
_offset = 0;
if (_scroll.hasClients) _scroll.jumpTo(0);
}
}
void _tick(Duration elapsed) {
if (!_overflow || !_scroll.hasClients) return;
final dt = _last == Duration.zero ? 0.0 : (elapsed - _last).inMicroseconds / 1e6;
_last = elapsed;
final span = _contentWidth + widget.gap;
if (span <= 0) return;
_offset = (_offset + widget.pxPerSecond * dt) % span;
final max = _scroll.position.maxScrollExtent;
_scroll.jumpTo(_offset.clamp(0, max));
}
@override
void dispose() {
_ticker.dispose();
_scroll.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return ClipRect(
child: LayoutBuilder(
builder: (ctx, constraints) {
_viewportWidth = constraints.maxWidth;
return SingleChildScrollView(
controller: _scroll,
scrollDirection: Axis.horizontal,
physics: const NeverScrollableScrollPhysics(),
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
KeyedSubtree(key: _childKey, child: widget.child),
if (_overflow) ...[SizedBox(width: widget.gap), widget.child],
],
),
);
},
),
);
}
}