From 4274d3f13e39d4640644acec2b57a4d9a9655bd7 Mon Sep 17 00:00:00 2001
From: Robert Santucci <rsantucc@fnal.gov>
Date: Fri, 2 Oct 2026 11:34:48 -0500
Subject: [PATCH 1/6] Add AppLog and LogPanel: an application log and a side
 panel to read it

---
 lib/flutter_controls_core.dart    |   6 +
 lib/src/logging/app_log.dart      | 199 ++++++++++++++
 lib/src/widgets/log_panel.dart    | 437 ++++++++++++++++++++++++++++++
 test/unit_tests/app_log_test.dart | 154 +++++++++++
 test/widget/log_panel_test.dart   | 105 +++++++
 5 files changed, 901 insertions(+)
 create mode 100644 lib/src/logging/app_log.dart
 create mode 100644 lib/src/widgets/log_panel.dart
 create mode 100644 test/unit_tests/app_log_test.dart
 create mode 100644 test/widget/log_panel_test.dart

diff --git a/lib/flutter_controls_core.dart b/lib/flutter_controls_core.dart
index d8ee48b..d66fb09 100644
--- a/lib/flutter_controls_core.dart
+++ b/lib/flutter_controls_core.dart
@@ -4,10 +4,12 @@ library;
 import "package:flutter/material.dart";
 import "package:flutter_controls_auth/flutter_controls_auth.dart";
 import 'package:go_router/go_router.dart';
+
 import 'src/app_scaffold.dart';
 import 'src/otel_tracing.dart';
 
 export 'src/app_scaffold.dart';
+
 export 'package:flutter_controls_auth/flutter_controls_auth.dart'
     show
         AuthInfo,
@@ -19,8 +21,12 @@ export 'package:flutter_controls_auth/flutter_controls_auth.dart'
         warningBox;
 
 export 'src/otel_tracing.dart' show AppTracer, appTracer, Span;
+export 'src/logging/app_log.dart'
+    show AppLog, LogEntry, LogLevel, appLog, logClock;
+export 'src/widgets/log_panel.dart' show LogPanel, logPanelWidth;
 export 'src/widgets/param_panel.dart' show ParameterPanel;
 export 'src/widgets/param_row.dart' show ParameterPanelRow;
+
 export 'package:bison_design_system/bison_design_system.dart';
 
 /// Entry point for Fermilab applications
diff --git a/lib/src/logging/app_log.dart b/lib/src/logging/app_log.dart
new file mode 100644
index 0000000..17d3a8d
--- /dev/null
+++ b/lib/src/logging/app_log.dart
@@ -0,0 +1,199 @@
+/// An application log: what the app saw, in order, for the operator.
+///
+/// Apps write transitions (a link lost, a write that failed), never every
+/// reading, to the shared [appLog] or to their own [AppLog]. The last
+/// [AppLog.capacity] entries are kept, and each is mirrored to the terminal
+/// or browser console. [LogPanel] shows them.
+library;
+
+import 'dart:async' show Timer;
+import 'dart:collection' show ListQueue;
+
+import 'package:flutter/foundation.dart'
+    show ChangeNotifier, debugPrint, immutable, visibleForTesting;
+
+/// `12:00:01.234`, local time.
+String logClock(DateTime t) {
+  String two(int n) => n.toString().padLeft(2, '0');
+  final l = t.toLocal();
+  return '${two(l.hour)}:${two(l.minute)}:${two(l.second)}.'
+      '${l.millisecond.toString().padLeft(3, '0')}';
+}
+
+/// How much an entry matters.
+enum LogLevel {
+  /// Something that happened (a subscription opened, a write confirmed).
+  info,
+
+  /// Something to look at (a lost link, a gateway flood, PVs failing).
+  warn,
+
+  /// Something that failed (a write that did not land).
+  error;
+
+  /// `INFO`, `WARN`, `ERROR`.
+  String get tag => name.toUpperCase();
+}
+
+/// One line of the log.
+@immutable
+class LogEntry {
+  /// Creates an entry.
+  const LogEntry(this.time, this.level, this.source, this.message);
+
+  /// When it was logged.
+  final DateTime time;
+
+  /// How much it matters.
+  final LogLevel level;
+
+  /// What logged it, chosen by the app (`app`, `link`, `write`, …).
+  final String source;
+
+  /// What happened, on one line.
+  final String message;
+
+  /// `12:00:01.234 WARN flood: booster: …`, local time.
+  String get line => '${logClock(time)} ${level.tag} $source: $message';
+
+  @override
+  String toString() => line;
+}
+
+/// A bounded, ordered log the UI can watch.
+///
+/// Listeners hear at most one notification per [notifyEvery], so a burst
+/// of entries rebuilds a panel once.
+class AppLog extends ChangeNotifier {
+  /// Creates a log keeping the last [capacity] entries; [now] replaces the
+  /// wall clock (tests).
+  AppLog({
+    this.name,
+    this.capacity = 500,
+    this.notifyEvery = const Duration(milliseconds: 250),
+    this.mirror = true,
+    DateTime Function()? now,
+  }) : assert(capacity > 0, 'capacity must be positive'),
+       now = now ?? DateTime.now;
+
+  /// Put before every mirrored line (the app's name), or nothing.
+  String? name;
+
+  /// How many entries are kept; the oldest is dropped beyond it.
+  final int capacity;
+
+  /// Listeners hear at most one notification per this interval.
+  final Duration notifyEvery;
+
+  /// Whether every entry is also printed (`debugPrint`), after [name] if
+  /// set: the terminal off the web, the browser console on it. Tests turn
+  /// it off.
+  bool mirror;
+
+  /// The clock entries are stamped with.
+  final DateTime Function() now;
+
+  /// A message longer than this is cut (an exception's text can be long).
+  static const int maxMessage = 1000;
+
+  final ListQueue<LogEntry> _entries = ListQueue<LogEntry>();
+  List<LogEntry>? _view;
+  int _dropped = 0;
+  Timer? _notify;
+  bool _disposed = false;
+
+  /// The entries, oldest first (unmodifiable).
+  List<LogEntry> get entries => _view ??= List.unmodifiable(_entries);
+
+  /// How many entries were dropped for [capacity] since the last [clear].
+  int get dropped => _dropped;
+
+  /// The entries at [min] or above, oldest first.
+  List<LogEntry> atLeast(LogLevel min) => min == LogLevel.info
+      ? entries
+      : [
+          for (final e in _entries)
+            if (e.level.index >= min.index) e,
+        ];
+
+  /// Logs [message] from [source] at [level] and returns the entry. Line
+  /// breaks in [message] become spaces.
+  LogEntry add(LogLevel level, String source, String message) {
+    final e = LogEntry(now(), level, source, _oneLine(message));
+    if (_entries.length >= capacity) {
+      _entries.removeFirst();
+      _dropped++;
+    }
+    _entries.addLast(e);
+    _view = null;
+    if (mirror) debugPrint(name == null ? e.line : '$name ${e.line}');
+    _schedule();
+    return e;
+  }
+
+  /// [add] at [LogLevel.info].
+  LogEntry info(String source, String message) =>
+      add(LogLevel.info, source, message);
+
+  /// [add] at [LogLevel.warn].
+  LogEntry warn(String source, String message) =>
+      add(LogLevel.warn, source, message);
+
+  /// [add] at [LogLevel.error].
+  LogEntry error(String source, String message) =>
+      add(LogLevel.error, source, message);
+
+  /// Drops every entry; listeners hear of it at once.
+  void clear() {
+    _entries.clear();
+    _view = null;
+    _dropped = 0;
+    _notify?.cancel();
+    _notify = null;
+    if (!_disposed) notifyListeners();
+  }
+
+  /// The entries at [min] or above as text to copy: one
+  /// [LogEntry.line] per entry, oldest first.
+  String asText({LogLevel min = LogLevel.info}) =>
+      [for (final e in atLeast(min)) e.line].join('\n');
+
+  /// Empties the log without telling anyone and forgets a pending
+  /// notification (tests: each starts from an empty log).
+  @visibleForTesting
+  void reset() {
+    _notify?.cancel();
+    _notify = null;
+    _entries.clear();
+    _view = null;
+    _dropped = 0;
+  }
+
+  static final RegExp _breaks = RegExp(r'\s*[\r\n]+\s*');
+
+  static String _oneLine(String message) {
+    final m = message.replaceAll(_breaks, ' ');
+    return m.length > maxMessage ? '${m.substring(0, maxMessage)}…' : m;
+  }
+
+  /// Nobody listening (the panel is closed): nothing to schedule; a panel
+  /// that opens later reads [entries] as it builds.
+  void _schedule() {
+    if (_disposed || _notify != null || !hasListeners) return;
+    _notify = Timer(notifyEvery, () {
+      _notify = null;
+      if (!_disposed) notifyListeners();
+    });
+  }
+
+  @override
+  void dispose() {
+    _disposed = true;
+    _notify?.cancel();
+    _notify = null;
+    super.dispose();
+  }
+}
+
+/// The shared application log (set [AppLog.name] to the app's name).
+final AppLog appLog = AppLog();
diff --git a/lib/src/widgets/log_panel.dart b/lib/src/widgets/log_panel.dart
new file mode 100644
index 0000000..7764b5f
--- /dev/null
+++ b/lib/src/widgets/log_panel.dart
@@ -0,0 +1,437 @@
+/// A side panel showing an [AppLog]: newest first, filtered to every entry,
+/// warnings and errors, or errors only. Copy puts the entries shown on the
+/// clipboard (oldest first, one line each); Clear empties the log.
+library;
+
+import 'dart:math' as math;
+
+import 'package:bison_design_system/bison_design_system.dart'
+    show BisonThemeTokens, BisonTypographyTokens;
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart' show Clipboard, ClipboardData;
+
+import '../logging/app_log.dart';
+
+/// The panel's default width.
+const double logPanelWidth = 600;
+
+/// The panel.
+class LogPanel extends StatefulWidget {
+  /// Creates the panel for [log] (the shared [appLog] when `null`);
+  /// [onClose] is its ✕.
+  const LogPanel({
+    required this.onClose,
+    this.log,
+    this.width = logPanelWidth,
+    super.key,
+  });
+
+  /// Closes the panel.
+  final VoidCallback onClose;
+
+  /// The log shown, or `null` for [appLog].
+  final AppLog? log;
+
+  /// The panel's width.
+  final double width;
+
+  @override
+  State<LogPanel> createState() => _LogPanelState();
+}
+
+class _LogPanelState extends State<LogPanel> {
+  LogLevel _min = LogLevel.info;
+
+  AppLog get _log => widget.log ?? appLog;
+
+  Future<void> _copy() async {
+    final n = _log.atLeast(_min).length;
+    await Clipboard.setData(ClipboardData(text: _log.asText(min: _min)));
+    if (!mounted) return;
+    ScaffoldMessenger.maybeOf(context)?.showSnackBar(
+      SnackBar(
+        content: Text('Copied $n log line${n == 1 ? '' : 's'}'),
+        duration: const Duration(seconds: 2),
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final look = _Look.of(context);
+    return Material(
+      color: look.surface,
+      elevation: 12,
+      child: Container(
+        width: widget.width,
+        decoration: BoxDecoration(
+          border: Border(left: BorderSide(color: look.border)),
+        ),
+        padding: const EdgeInsets.fromLTRB(8, 4, 8, 6),
+        child: ListenableBuilder(
+          listenable: _log,
+          builder: (context, _) {
+            final all = _log.entries;
+            final shown = _log.atLeast(_min);
+            return Column(
+              crossAxisAlignment: CrossAxisAlignment.stretch,
+              children: [
+                _header(look, all.length, shown.length),
+                Divider(height: 9, color: look.border),
+                Expanded(
+                  child: shown.isEmpty
+                      ? Center(
+                          child: Text(
+                            all.isEmpty
+                                ? 'Nothing logged yet'
+                                : _min == LogLevel.warn
+                                ? 'No warnings or errors'
+                                : 'No errors',
+                            style: look.body.copyWith(color: look.label),
+                          ),
+                        )
+                      : _list(context, look, shown),
+                ),
+              ],
+            );
+          },
+        ),
+      ),
+    );
+  }
+
+  Widget _header(_Look look, int total, int shown) {
+    final dropped = _log.dropped;
+    final count = [
+      _min == LogLevel.info
+          ? '$total entr${total == 1 ? 'y' : 'ies'}'
+          : '$shown of $total',
+      if (dropped > 0) '$dropped older dropped',
+    ].join(' · ');
+    return Row(
+      children: [
+        Text(
+          'Log',
+          style: look.body.copyWith(
+            fontSize: 13,
+            fontWeight: FontWeight.bold,
+            color: look.title,
+          ),
+        ),
+        const SizedBox(width: 10),
+        Expanded(
+          child: Text(
+            count,
+            key: const ValueKey('log-count'),
+            maxLines: 1,
+            overflow: TextOverflow.ellipsis,
+            style: look.body.copyWith(color: look.label),
+          ),
+        ),
+        _Filter(
+          look: look,
+          value: _min,
+          onChanged: (l) => setState(() => _min = l),
+        ),
+        const SizedBox(width: 8),
+        _HeaderButton(
+          look: look,
+          id: 'log-copy',
+          icon: Icons.copy,
+          label: 'Copy',
+          tooltip: 'copy the entries shown, oldest first, one line each',
+          onPressed: shown == 0 ? null : _copy,
+        ),
+        _HeaderButton(
+          look: look,
+          id: 'log-clear',
+          icon: Icons.delete_outline,
+          label: 'Clear',
+          tooltip: 'empty the log',
+          onPressed: total == 0 ? null : _log.clear,
+        ),
+        IconButton(
+          key: const ValueKey('log-close'),
+          tooltip: 'close',
+          iconSize: 16,
+          color: look.text,
+          visualDensity: VisualDensity.compact,
+          onPressed: widget.onClose,
+          icon: const Icon(Icons.close),
+        ),
+      ],
+    );
+  }
+
+  /// Newest first; time, level and source in columns as wide as their
+  /// widest text, the message wrapping beside them.
+  Widget _list(BuildContext context, _Look look, List<LogEntry> shown) {
+    final scaler = MediaQuery.textScalerOf(context);
+    double width(String text) {
+      final p = TextPainter(
+        text: TextSpan(text: text, style: look.body),
+        textDirection: TextDirection.ltr,
+        textScaler: scaler,
+        maxLines: 1,
+      )..layout();
+      final w = p.width;
+      p.dispose();
+      return w.ceilToDouble();
+    }
+
+    final sources = {for (final e in shown) e.source};
+    final columns = (
+      time: width('00:00:00.000'),
+      level: width(LogLevel.error.tag),
+      source: sources.map(width).fold<double>(0, math.max),
+    );
+    return ListView.builder(
+      key: const ValueKey('log-list'),
+      itemCount: shown.length,
+      itemBuilder: (context, i) => _EntryRow(
+        look: look,
+        entry: shown[shown.length - 1 - i],
+        columns: columns,
+      ),
+    );
+  }
+}
+
+/// The panel's colours and text style: the Bison tokens when the theme
+/// carries them, else the Material colour scheme.
+class _Look {
+  const _Look({
+    required this.surface,
+    required this.border,
+    required this.title,
+    required this.text,
+    required this.muted,
+    required this.label,
+    required this.source,
+    required this.warn,
+    required this.error,
+    required this.selected,
+    required this.disabled,
+    required this.body,
+  });
+
+  factory _Look.of(BuildContext context) {
+    final theme = Theme.of(context);
+    final typography = theme.extension<BisonTypographyTokens>();
+    final body =
+        (typography?.bodySmall ??
+                theme.textTheme.bodySmall ??
+                const TextStyle())
+            .copyWith(
+              fontSize: 11,
+              fontFeatures: const [FontFeature.tabularFigures()],
+            );
+    final t = theme.extension<BisonThemeTokens>();
+    if (t != null) {
+      return _Look(
+        surface: t.surfaceDefault,
+        border: t.borderPlain,
+        title: t.textPrimary,
+        text: t.textPlain,
+        muted: t.textMuted,
+        label: t.textSecondary,
+        source: t.textPrimary,
+        warn: t.iconWarning,
+        error: t.textError,
+        selected: t.surfacePressed,
+        disabled: t.textDisabled,
+        body: body.copyWith(color: t.textPlain),
+      );
+    }
+    final s = theme.colorScheme;
+    return _Look(
+      surface: s.surface,
+      border: s.outlineVariant,
+      title: s.primary,
+      text: s.onSurface,
+      muted: s.onSurfaceVariant,
+      label: s.onSurfaceVariant,
+      source: s.primary,
+      warn: Colors.amber.shade700,
+      error: s.error,
+      selected: s.primary.withValues(alpha: 0.16),
+      disabled: s.onSurface.withValues(alpha: 0.38),
+      body: body.copyWith(color: s.onSurface),
+    );
+  }
+
+  final Color surface;
+  final Color border;
+  final Color title;
+  final Color text;
+  final Color muted;
+  final Color label;
+  final Color source;
+  final Color warn;
+  final Color error;
+  final Color selected;
+  final Color disabled;
+  final TextStyle body;
+
+  /// The colour an entry's level is drawn in.
+  Color level(LogLevel l) => switch (l) {
+    LogLevel.info => text,
+    LogLevel.warn => warn,
+    LogLevel.error => error,
+  };
+}
+
+/// One entry: `12:00:01.234  WARN  link  message…`.
+class _EntryRow extends StatelessWidget {
+  const _EntryRow({
+    required this.look,
+    required this.entry,
+    required this.columns,
+  });
+
+  final _Look look;
+  final LogEntry entry;
+  final ({double time, double level, double source}) columns;
+
+  @override
+  Widget build(BuildContext context) {
+    const gap = SizedBox(width: 8);
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 1.5),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          SizedBox(
+            width: columns.time,
+            child: Text(
+              logClock(entry.time),
+              style: look.body.copyWith(color: look.muted),
+            ),
+          ),
+          gap,
+          SizedBox(
+            width: columns.level,
+            child: Text(
+              entry.level.tag,
+              style: look.body.copyWith(
+                color: look.level(entry.level),
+                fontWeight: entry.level == LogLevel.info
+                    ? FontWeight.normal
+                    : FontWeight.bold,
+              ),
+            ),
+          ),
+          gap,
+          SizedBox(
+            width: columns.source,
+            child: Text(
+              entry.source,
+              style: look.body.copyWith(color: look.source),
+            ),
+          ),
+          gap,
+          Expanded(child: Text(entry.message, style: look.body)),
+        ],
+      ),
+    );
+  }
+}
+
+/// All · Warnings · Errors, joined.
+class _Filter extends StatelessWidget {
+  const _Filter({
+    required this.look,
+    required this.value,
+    required this.onChanged,
+  });
+
+  final _Look look;
+  final LogLevel value;
+  final ValueChanged<LogLevel> onChanged;
+
+  static String _label(LogLevel l) => switch (l) {
+    LogLevel.info => 'All',
+    LogLevel.warn => 'Warnings',
+    LogLevel.error => 'Errors',
+  };
+
+  static String _tip(LogLevel l) => switch (l) {
+    LogLevel.info => 'every entry',
+    LogLevel.warn => 'warnings and errors',
+    LogLevel.error => 'errors only',
+  };
+
+  @override
+  Widget build(BuildContext context) => Container(
+    height: 24,
+    decoration: BoxDecoration(
+      border: Border.all(color: look.border),
+      borderRadius: BorderRadius.circular(3),
+    ),
+    clipBehavior: Clip.antiAlias,
+    child: Row(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        for (final l in LogLevel.values)
+          Tooltip(
+            message: _tip(l),
+            child: InkWell(
+              key: ValueKey('log-filter-${l.name}'),
+              onTap: () => onChanged(l),
+              child: Container(
+                color: l == value ? look.selected : null,
+                padding: const EdgeInsets.symmetric(horizontal: 8),
+                alignment: Alignment.center,
+                child: Text(
+                  _label(l),
+                  style: look.body.copyWith(
+                    fontWeight: FontWeight.w500,
+                    color: l == value ? look.title : look.text,
+                  ),
+                ),
+              ),
+            ),
+          ),
+      ],
+    ),
+  );
+}
+
+/// A small text button with an icon, for the header.
+class _HeaderButton extends StatelessWidget {
+  const _HeaderButton({
+    required this.look,
+    required this.id,
+    required this.icon,
+    required this.label,
+    required this.tooltip,
+    required this.onPressed,
+  });
+
+  final _Look look;
+  final String id;
+  final IconData icon;
+  final String label;
+  final String tooltip;
+  final VoidCallback? onPressed;
+
+  @override
+  Widget build(BuildContext context) => Tooltip(
+    message: tooltip,
+    child: TextButton.icon(
+      key: ValueKey(id),
+      style: TextButton.styleFrom(
+        visualDensity: VisualDensity.compact,
+        tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+        minimumSize: const Size(0, 24),
+        padding: const EdgeInsets.symmetric(horizontal: 6),
+        foregroundColor: look.text,
+        disabledForegroundColor: look.disabled,
+        textStyle: look.body,
+      ),
+      onPressed: onPressed,
+      icon: Icon(icon, size: 14),
+      label: Text(label),
+    ),
+  );
+}
diff --git a/test/unit_tests/app_log_test.dart b/test/unit_tests/app_log_test.dart
new file mode 100644
index 0000000..7022cdf
--- /dev/null
+++ b/test/unit_tests/app_log_test.dart
@@ -0,0 +1,154 @@
+import 'package:flutter/foundation.dart' show DebugPrintCallback, debugPrint;
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:flutter_controls_core/flutter_controls_core.dart'
+    show AppLog, LogLevel, appLog;
+
+void main() {
+  late DateTime clock;
+  late AppLog log;
+
+  setUp(() {
+    clock = DateTime(2026, 10, 1, 12, 0, 1, 234);
+    log = AppLog(mirror: false, now: () => clock);
+  });
+
+  tearDown(() => log.dispose());
+
+  test('keeps the last capacity entries, oldest first, and counts what '
+      'it dropped', () {
+    final small = AppLog(capacity: 3, mirror: false, now: () => clock);
+    for (var k = 1; k <= 5; k++) {
+      small.info('app', 'entry $k');
+    }
+    expect(
+      [for (final e in small.entries) e.message],
+      ['entry 3', 'entry 4', 'entry 5'],
+    );
+    expect(small.dropped, 2);
+    expect(
+      () => small.entries.add(small.entries.first),
+      throwsUnsupportedError,
+      reason: 'unmodifiable',
+    );
+    small.clear();
+    expect(small.entries, isEmpty);
+    expect(small.dropped, 0);
+    small.dispose();
+  });
+
+  test('the default capacity is 500', () {
+    for (var k = 0; k < 520; k++) {
+      log.info('app', '$k');
+    }
+    expect(log.entries, hasLength(500));
+    expect(log.entries.first.message, '20');
+    expect(log.dropped, 20);
+  });
+
+  test('levels: the helpers, the filter and the text to copy', () {
+    log
+      ..info('app', 'started')
+      ..warn('flood', 'gateway flood')
+      ..error('write', 'TBT ON failed')
+      ..add(LogLevel.warn, 'link', 'stream error');
+    expect(
+      [for (final e in log.entries) e.level],
+      [LogLevel.info, LogLevel.warn, LogLevel.error, LogLevel.warn],
+    );
+    expect(log.atLeast(LogLevel.info), hasLength(4));
+    expect(
+      [for (final e in log.atLeast(LogLevel.warn)) e.source],
+      ['flood', 'write', 'link'],
+    );
+    expect(log.atLeast(LogLevel.error).single.source, 'write');
+    expect(
+      log.asText(),
+      '12:00:01.234 INFO app: started\n'
+      '12:00:01.234 WARN flood: gateway flood\n'
+      '12:00:01.234 ERROR write: TBT ON failed\n'
+      '12:00:01.234 WARN link: stream error',
+    );
+    expect(
+      log.asText(min: LogLevel.error),
+      '12:00:01.234 ERROR write: TBT ON failed',
+    );
+    expect(log.entries.first.toString(), '12:00:01.234 INFO app: started');
+  });
+
+  test('a message is kept on one line, and a huge one is cut', () {
+    log.info('link', 'stream error: socket closed\n  at line 3\r\nend');
+    expect(
+      log.entries.single.message,
+      'stream error: socket closed at line 3 end',
+    );
+    log.info('link', 'x' * 5000);
+    expect(log.entries.last.message, hasLength(AppLog.maxMessage + 1));
+    expect(log.entries.last.message, endsWith('…'));
+  });
+
+  testWidgets('a burst of entries is one notification, at most every '
+      '250 ms', (tester) async {
+    var notified = 0;
+    log.addListener(() => notified++);
+    for (var k = 0; k < 50; k++) {
+      log.info('pv', 'entry $k');
+    }
+    expect(notified, 0, reason: 'nothing before the interval');
+    await tester.pump(const Duration(milliseconds: 249));
+    expect(notified, 0);
+    await tester.pump(const Duration(milliseconds: 1));
+    expect(notified, 1);
+    log.warn('flood', 'one more');
+    await tester.pump(const Duration(milliseconds: 100));
+    log.warn('flood', 'and another');
+    await tester.pump(const Duration(milliseconds: 150));
+    expect(notified, 2);
+    await tester.pump(const Duration(seconds: 1));
+    expect(notified, 2, reason: 'quiet: nothing more');
+    log.clear();
+    expect(notified, 3, reason: 'Clear is shown at once');
+  });
+
+  testWidgets('with nobody listening nothing is scheduled', (tester) async {
+    log.info('app', 'quiet');
+    // No timer may be left pending: the test would fail if one were.
+    expect(log.entries, hasLength(1));
+  });
+
+  test('every entry is mirrored to the console, unless turned off', () {
+    final printed = <String?>[];
+    final DebugPrintCallback saved = debugPrint;
+    debugPrint = (message, {wrapWidth}) => printed.add(message);
+    try {
+      final loud = AppLog(name: 'my-app', now: () => clock)
+        ..warn('flood', 'gateway flood: 1500 junk rows/s');
+      expect(printed, [
+        'my-app 12:00:01.234 WARN flood: gateway flood: 1500 junk rows/s',
+      ]);
+      loud.mirror = false;
+      loud.info('app', 'quiet');
+      log.error('write', 'not printed either');
+      expect(printed, hasLength(1));
+      expect(loud.entries, hasLength(2), reason: 'still logged');
+      loud.dispose();
+      final plain = AppLog(now: () => clock)..info('app', 'no name');
+      expect(printed.last, '12:00:01.234 INFO app: no name');
+      plain.dispose();
+    } finally {
+      debugPrint = saved;
+    }
+  });
+
+  test('reset empties the shared log without a notification', () {
+    var notified = 0;
+    void count() => notified++;
+    appLog
+      ..addListener(count)
+      ..info('app', 'from an earlier test')
+      ..reset();
+    expect(appLog.entries, isEmpty);
+    expect(notified, 0);
+    appLog.removeListener(count);
+  });
+}
diff --git a/test/widget/log_panel_test.dart b/test/widget/log_panel_test.dart
new file mode 100644
index 0000000..5fb2896
--- /dev/null
+++ b/test/widget/log_panel_test.dart
@@ -0,0 +1,105 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:flutter_controls_core/flutter_controls_core.dart'
+    show AppLog, BisonThemeData, BisonThemeTokens, LogPanel;
+
+Widget _host(AppLog log, {ThemeData? theme, VoidCallback? onClose}) =>
+    MaterialApp(
+      theme: theme ?? BisonThemeData.dark(),
+      home: Scaffold(
+        body: Align(
+          alignment: Alignment.centerRight,
+          child: LogPanel(log: log, onClose: onClose ?? () {}),
+        ),
+      ),
+    );
+
+AppLog _filled() {
+  final log = AppLog(mirror: false, now: () => DateTime(2026, 10, 1, 12));
+  log
+    ..info('link', 'subscription opened')
+    ..warn('flood', 'gateway flood')
+    ..error('write', 'write failed');
+  return log;
+}
+
+Color? _colour(WidgetTester tester, String text) =>
+    tester.widget<Text>(find.text(text)).style?.color;
+
+void main() {
+  testWidgets('lists newest first, coloured from the Bison theme', (
+    tester,
+  ) async {
+    final log = _filled();
+    await tester.pumpWidget(_host(log));
+    final y = [
+      for (final m in ['write failed', 'gateway flood', 'subscription opened'])
+        tester.getTopLeft(find.text(m)).dy,
+    ];
+    expect(y, orderedEquals([...y]..sort()));
+    final tokens = BisonThemeData.dark().extension<BisonThemeTokens>()!;
+    expect(_colour(tester, 'WARN'), tokens.iconWarning);
+    expect(_colour(tester, 'ERROR'), tokens.textError);
+    expect(find.text('3 entries'), findsOneWidget);
+    log.dispose();
+  });
+
+  testWidgets('filters to warnings and errors, then errors', (tester) async {
+    final log = _filled();
+    await tester.pumpWidget(_host(log));
+    await tester.tap(find.byKey(const ValueKey('log-filter-warn')));
+    await tester.pump();
+    expect(find.text('subscription opened'), findsNothing);
+    expect(find.text('2 of 3'), findsOneWidget);
+    await tester.tap(find.byKey(const ValueKey('log-filter-error')));
+    await tester.pump();
+    expect(find.text('gateway flood'), findsNothing);
+    expect(find.text('write failed'), findsOneWidget);
+    log.dispose();
+  });
+
+  testWidgets('Copy puts the entries shown on the clipboard, oldest first', (
+    tester,
+  ) async {
+    String? copied;
+    tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
+      SystemChannels.platform,
+      (call) async {
+        if (call.method == 'Clipboard.setData') {
+          copied = (call.arguments as Map)['text'] as String?;
+        }
+        return null;
+      },
+    );
+    final log = _filled();
+    await tester.pumpWidget(_host(log));
+    await tester.tap(find.byKey(const ValueKey('log-copy')));
+    await tester.pump();
+    expect(copied, log.asText());
+    expect(copied!.split('\n').first, endsWith('subscription opened'));
+    log.dispose();
+  });
+
+  testWidgets('Clear empties the log; ✕ calls onClose', (tester) async {
+    var closed = 0;
+    final log = _filled();
+    await tester.pumpWidget(_host(log, onClose: () => closed++));
+    await tester.tap(find.byKey(const ValueKey('log-clear')));
+    await tester.pump();
+    expect(log.entries, isEmpty);
+    expect(find.text('Nothing logged yet'), findsOneWidget);
+    await tester.tap(find.byKey(const ValueKey('log-close')));
+    expect(closed, 1);
+    log.dispose();
+  });
+
+  testWidgets('works under a plain Material theme too', (tester) async {
+    final log = _filled();
+    await tester.pumpWidget(_host(log, theme: ThemeData.dark()));
+    expect(tester.takeException(), isNull);
+    expect(_colour(tester, 'ERROR'), ThemeData.dark().colorScheme.error);
+    log.dispose();
+  });
+}

From f54bafdb9478b4ebc46fb67d2ec1a93aed1e4f0b Mon Sep 17 00:00:00 2001
From: Robert Santucci <rsantucc@fnal.gov>
Date: Mon, 5 Oct 2026 08:32:29 -0500
Subject: [PATCH 2/6] LogPanel: icon-only header buttons so the header fits a
 narrow panel

Copy, Clear and close are icon buttons; their tooltips name them.
---
 lib/src/widgets/log_panel.dart  | 48 ++++++++++++---------------------
 test/widget/log_panel_test.dart | 33 ++++++++++++++++-------
 2 files changed, 40 insertions(+), 41 deletions(-)

diff --git a/lib/src/widgets/log_panel.dart b/lib/src/widgets/log_panel.dart
index 7764b5f..b352c0e 100644
--- a/lib/src/widgets/log_panel.dart
+++ b/lib/src/widgets/log_panel.dart
@@ -138,26 +138,22 @@ class _LogPanelState extends State<LogPanel> {
           look: look,
           id: 'log-copy',
           icon: Icons.copy,
-          label: 'Copy',
-          tooltip: 'copy the entries shown, oldest first, one line each',
+          tooltip: 'Copy the entries shown',
           onPressed: shown == 0 ? null : _copy,
         ),
         _HeaderButton(
           look: look,
           id: 'log-clear',
           icon: Icons.delete_outline,
-          label: 'Clear',
-          tooltip: 'empty the log',
+          tooltip: 'Clear the log',
           onPressed: total == 0 ? null : _log.clear,
         ),
-        IconButton(
-          key: const ValueKey('log-close'),
-          tooltip: 'close',
-          iconSize: 16,
-          color: look.text,
-          visualDensity: VisualDensity.compact,
+        _HeaderButton(
+          look: look,
+          id: 'log-close',
+          icon: Icons.close,
+          tooltip: 'Close',
           onPressed: widget.onClose,
-          icon: const Icon(Icons.close),
         ),
       ],
     );
@@ -397,13 +393,12 @@ class _Filter extends StatelessWidget {
   );
 }
 
-/// A small text button with an icon, for the header.
+/// A small icon button for the header; its tooltip names it.
 class _HeaderButton extends StatelessWidget {
   const _HeaderButton({
     required this.look,
     required this.id,
     required this.icon,
-    required this.label,
     required this.tooltip,
     required this.onPressed,
   });
@@ -411,27 +406,18 @@ class _HeaderButton extends StatelessWidget {
   final _Look look;
   final String id;
   final IconData icon;
-  final String label;
   final String tooltip;
   final VoidCallback? onPressed;
 
   @override
-  Widget build(BuildContext context) => Tooltip(
-    message: tooltip,
-    child: TextButton.icon(
-      key: ValueKey(id),
-      style: TextButton.styleFrom(
-        visualDensity: VisualDensity.compact,
-        tapTargetSize: MaterialTapTargetSize.shrinkWrap,
-        minimumSize: const Size(0, 24),
-        padding: const EdgeInsets.symmetric(horizontal: 6),
-        foregroundColor: look.text,
-        disabledForegroundColor: look.disabled,
-        textStyle: look.body,
-      ),
-      onPressed: onPressed,
-      icon: Icon(icon, size: 14),
-      label: Text(label),
-    ),
+  Widget build(BuildContext context) => IconButton(
+    key: ValueKey(id),
+    tooltip: tooltip,
+    iconSize: 16,
+    color: look.text,
+    disabledColor: look.disabled,
+    visualDensity: VisualDensity.compact,
+    onPressed: onPressed,
+    icon: Icon(icon),
   );
 }
diff --git a/test/widget/log_panel_test.dart b/test/widget/log_panel_test.dart
index 5fb2896..5e5edee 100644
--- a/test/widget/log_panel_test.dart
+++ b/test/widget/log_panel_test.dart
@@ -5,16 +5,20 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_controls_core/flutter_controls_core.dart'
     show AppLog, BisonThemeData, BisonThemeTokens, LogPanel;
 
-Widget _host(AppLog log, {ThemeData? theme, VoidCallback? onClose}) =>
-    MaterialApp(
-      theme: theme ?? BisonThemeData.dark(),
-      home: Scaffold(
-        body: Align(
-          alignment: Alignment.centerRight,
-          child: LogPanel(log: log, onClose: onClose ?? () {}),
-        ),
-      ),
-    );
+Widget _host(
+  AppLog log, {
+  ThemeData? theme,
+  VoidCallback? onClose,
+  double width = 600,
+}) => MaterialApp(
+  theme: theme ?? BisonThemeData.dark(),
+  home: Scaffold(
+    body: Align(
+      alignment: Alignment.centerRight,
+      child: LogPanel(log: log, onClose: onClose ?? () {}, width: width),
+    ),
+  ),
+);
 
 AppLog _filled() {
   final log = AppLog(mirror: false, now: () => DateTime(2026, 10, 1, 12));
@@ -95,6 +99,15 @@ void main() {
     log.dispose();
   });
 
+  testWidgets('the header fits a narrow panel', (tester) async {
+    final log = _filled();
+    await tester.pumpWidget(_host(log, width: 440));
+    expect(tester.takeException(), isNull);
+    expect(find.byTooltip('Copy the entries shown'), findsOneWidget);
+    expect(find.byTooltip('Clear the log'), findsOneWidget);
+    log.dispose();
+  });
+
   testWidgets('works under a plain Material theme too', (tester) async {
     final log = _filled();
     await tester.pumpWidget(_host(log, theme: ThemeData.dark()));

From 8e78c447525ae895b17bc590627f80f1146ed431 Mon Sep 17 00:00:00 2001
From: Robert Santucci <rsantucc@fnal.gov>
Date: Mon, 5 Oct 2026 08:44:44 -0500
Subject: [PATCH 3/6] Shorten AppLog and LogPanel

---
 lib/flutter_controls_core.dart |   3 -
 lib/src/logging/app_log.dart   | 137 +++-------
 lib/src/widgets/log_panel.dart | 456 ++++++++++++---------------------
 3 files changed, 211 insertions(+), 385 deletions(-)

diff --git a/lib/flutter_controls_core.dart b/lib/flutter_controls_core.dart
index d66fb09..e02b98a 100644
--- a/lib/flutter_controls_core.dart
+++ b/lib/flutter_controls_core.dart
@@ -4,12 +4,10 @@ library;
 import "package:flutter/material.dart";
 import "package:flutter_controls_auth/flutter_controls_auth.dart";
 import 'package:go_router/go_router.dart';
-
 import 'src/app_scaffold.dart';
 import 'src/otel_tracing.dart';
 
 export 'src/app_scaffold.dart';
-
 export 'package:flutter_controls_auth/flutter_controls_auth.dart'
     show
         AuthInfo,
@@ -26,7 +24,6 @@ export 'src/logging/app_log.dart'
 export 'src/widgets/log_panel.dart' show LogPanel, logPanelWidth;
 export 'src/widgets/param_panel.dart' show ParameterPanel;
 export 'src/widgets/param_row.dart' show ParameterPanelRow;
-
 export 'package:bison_design_system/bison_design_system.dart';
 
 /// Entry point for Fermilab applications
diff --git a/lib/src/logging/app_log.dart b/lib/src/logging/app_log.dart
index 17d3a8d..9258b91 100644
--- a/lib/src/logging/app_log.dart
+++ b/lib/src/logging/app_log.dart
@@ -1,9 +1,5 @@
-/// An application log: what the app saw, in order, for the operator.
-///
-/// Apps write transitions (a link lost, a write that failed), never every
-/// reading, to the shared [appLog] or to their own [AppLog]. The last
-/// [AppLog.capacity] entries are kept, and each is mirrored to the terminal
-/// or browser console. [LogPanel] shows them.
+/// An app log for notable events (transitions, not readings), mirrored to
+/// the console and shown by `LogPanel`.
 library;
 
 import 'dart:async' show Timer;
@@ -12,61 +8,43 @@ import 'dart:collection' show ListQueue;
 import 'package:flutter/foundation.dart'
     show ChangeNotifier, debugPrint, immutable, visibleForTesting;
 
-/// `12:00:01.234`, local time.
+/// [t] as local `HH:MM:SS.mmm`.
 String logClock(DateTime t) {
-  String two(int n) => n.toString().padLeft(2, '0');
   final l = t.toLocal();
-  return '${two(l.hour)}:${two(l.minute)}:${two(l.second)}.'
-      '${l.millisecond.toString().padLeft(3, '0')}';
+  String p(int n, [int w = 2]) => '$n'.padLeft(w, '0');
+  return '${p(l.hour)}:${p(l.minute)}:${p(l.second)}.${p(l.millisecond, 3)}';
 }
 
-/// How much an entry matters.
 enum LogLevel {
-  /// Something that happened (a subscription opened, a write confirmed).
   info,
-
-  /// Something to look at (a lost link, a gateway flood, PVs failing).
   warn,
-
-  /// Something that failed (a write that did not land).
   error;
 
   /// `INFO`, `WARN`, `ERROR`.
   String get tag => name.toUpperCase();
 }
 
-/// One line of the log.
 @immutable
 class LogEntry {
-  /// Creates an entry.
   const LogEntry(this.time, this.level, this.source, this.message);
 
-  /// When it was logged.
   final DateTime time;
-
-  /// How much it matters.
   final LogLevel level;
 
-  /// What logged it, chosen by the app (`app`, `link`, `write`, …).
+  /// Who logged it, e.g. `link`.
   final String source;
-
-  /// What happened, on one line.
   final String message;
 
-  /// `12:00:01.234 WARN flood: booster: …`, local time.
+  /// `12:00:01.234 WARN link: message`.
   String get line => '${logClock(time)} ${level.tag} $source: $message';
 
   @override
   String toString() => line;
 }
 
-/// A bounded, ordered log the UI can watch.
-///
-/// Listeners hear at most one notification per [notifyEvery], so a burst
-/// of entries rebuilds a panel once.
+/// Keeps the last [capacity] entries; notifies at most once per
+/// [notifyEvery].
 class AppLog extends ChangeNotifier {
-  /// Creates a log keeping the last [capacity] entries; [now] replaces the
-  /// wall clock (tests).
   AppLog({
     this.name,
     this.capacity = 500,
@@ -76,124 +54,91 @@ class AppLog extends ChangeNotifier {
   }) : assert(capacity > 0, 'capacity must be positive'),
        now = now ?? DateTime.now;
 
-  /// Put before every mirrored line (the app's name), or nothing.
+  /// Prefix for console lines, e.g. the app's name.
   String? name;
-
-  /// How many entries are kept; the oldest is dropped beyond it.
   final int capacity;
-
-  /// Listeners hear at most one notification per this interval.
   final Duration notifyEvery;
 
-  /// Whether every entry is also printed (`debugPrint`), after [name] if
-  /// set: the terminal off the web, the browser console on it. Tests turn
-  /// it off.
+  /// Whether entries also go to `debugPrint`.
   bool mirror;
-
-  /// The clock entries are stamped with.
   final DateTime Function() now;
 
-  /// A message longer than this is cut (an exception's text can be long).
+  /// Longer messages are cut.
   static const int maxMessage = 1000;
+  static final RegExp _breaks = RegExp(r'\s*[\r\n]+\s*');
 
-  final ListQueue<LogEntry> _entries = ListQueue<LogEntry>();
-  List<LogEntry>? _view;
+  final ListQueue<LogEntry> _entries = ListQueue();
   int _dropped = 0;
   Timer? _notify;
   bool _disposed = false;
 
-  /// The entries, oldest first (unmodifiable).
-  List<LogEntry> get entries => _view ??= List.unmodifiable(_entries);
+  /// Oldest first.
+  List<LogEntry> get entries => List.unmodifiable(_entries);
 
-  /// How many entries were dropped for [capacity] since the last [clear].
+  /// Entries dropped over [capacity] since the last [clear].
   int get dropped => _dropped;
 
-  /// The entries at [min] or above, oldest first.
-  List<LogEntry> atLeast(LogLevel min) => min == LogLevel.info
-      ? entries
-      : [
-          for (final e in _entries)
-            if (e.level.index >= min.index) e,
-        ];
+  /// Entries at [min] or above, oldest first.
+  List<LogEntry> atLeast(LogLevel min) =>
+      List.unmodifiable(_entries.where((e) => e.level.index >= min.index));
 
-  /// Logs [message] from [source] at [level] and returns the entry. Line
-  /// breaks in [message] become spaces.
+  /// Logs [message] on one line, cut to [maxMessage].
   LogEntry add(LogLevel level, String source, String message) {
-    final e = LogEntry(now(), level, source, _oneLine(message));
+    var m = message.replaceAll(_breaks, ' ');
+    if (m.length > maxMessage) m = '${m.substring(0, maxMessage)}…';
+    final e = LogEntry(now(), level, source, m);
     if (_entries.length >= capacity) {
       _entries.removeFirst();
       _dropped++;
     }
     _entries.addLast(e);
-    _view = null;
     if (mirror) debugPrint(name == null ? e.line : '$name ${e.line}');
-    _schedule();
+    if (!_disposed && _notify == null && hasListeners) {
+      _notify = Timer(notifyEvery, () {
+        _notify = null;
+        if (!_disposed) notifyListeners();
+      });
+    }
     return e;
   }
 
-  /// [add] at [LogLevel.info].
   LogEntry info(String source, String message) =>
       add(LogLevel.info, source, message);
 
-  /// [add] at [LogLevel.warn].
   LogEntry warn(String source, String message) =>
       add(LogLevel.warn, source, message);
 
-  /// [add] at [LogLevel.error].
   LogEntry error(String source, String message) =>
       add(LogLevel.error, source, message);
 
-  /// Drops every entry; listeners hear of it at once.
+  /// One [LogEntry.line] per entry at [min] or above, oldest first.
+  String asText({LogLevel min = LogLevel.info}) =>
+      atLeast(min).map((e) => e.line).join('\n');
+
+  /// Empties the log and notifies at once.
   void clear() {
-    _entries.clear();
-    _view = null;
-    _dropped = 0;
-    _notify?.cancel();
-    _notify = null;
+    _empty();
     if (!_disposed) notifyListeners();
   }
 
-  /// The entries at [min] or above as text to copy: one
-  /// [LogEntry.line] per entry, oldest first.
-  String asText({LogLevel min = LogLevel.info}) =>
-      [for (final e in atLeast(min)) e.line].join('\n');
-
-  /// Empties the log without telling anyone and forgets a pending
-  /// notification (tests: each starts from an empty log).
+  /// Empties the log without notifying.
   @visibleForTesting
-  void reset() {
+  void reset() => _empty();
+
+  void _empty() {
     _notify?.cancel();
     _notify = null;
     _entries.clear();
-    _view = null;
     _dropped = 0;
   }
 
-  static final RegExp _breaks = RegExp(r'\s*[\r\n]+\s*');
-
-  static String _oneLine(String message) {
-    final m = message.replaceAll(_breaks, ' ');
-    return m.length > maxMessage ? '${m.substring(0, maxMessage)}…' : m;
-  }
-
-  /// Nobody listening (the panel is closed): nothing to schedule; a panel
-  /// that opens later reads [entries] as it builds.
-  void _schedule() {
-    if (_disposed || _notify != null || !hasListeners) return;
-    _notify = Timer(notifyEvery, () {
-      _notify = null;
-      if (!_disposed) notifyListeners();
-    });
-  }
-
   @override
   void dispose() {
     _disposed = true;
     _notify?.cancel();
-    _notify = null;
     super.dispose();
   }
 }
 
-/// The shared application log (set [AppLog.name] to the app's name).
+/// The shared log.
 final AppLog appLog = AppLog();
diff --git a/lib/src/widgets/log_panel.dart b/lib/src/widgets/log_panel.dart
index b352c0e..64ac586 100644
--- a/lib/src/widgets/log_panel.dart
+++ b/lib/src/widgets/log_panel.dart
@@ -1,6 +1,5 @@
-/// A side panel showing an [AppLog]: newest first, filtered to every entry,
-/// warnings and errors, or errors only. Copy puts the entries shown on the
-/// clipboard (oldest first, one line each); Clear empties the log.
+/// A side panel listing an [AppLog], newest first, with a level filter,
+/// Copy and Clear.
 library;
 
 import 'dart:math' as math;
@@ -12,13 +11,9 @@ import 'package:flutter/services.dart' show Clipboard, ClipboardData;
 
 import '../logging/app_log.dart';
 
-/// The panel's default width.
 const double logPanelWidth = 600;
 
-/// The panel.
 class LogPanel extends StatefulWidget {
-  /// Creates the panel for [log] (the shared [appLog] when `null`);
-  /// [onClose] is its ✕.
   const LogPanel({
     required this.onClose,
     this.log,
@@ -26,13 +21,11 @@ class LogPanel extends StatefulWidget {
     super.key,
   });
 
-  /// Closes the panel.
+  /// Called by the close button.
   final VoidCallback onClose;
 
-  /// The log shown, or `null` for [appLog].
+  /// Defaults to [appLog].
   final AppLog? log;
-
-  /// The panel's width.
   final double width;
 
   @override
@@ -40,12 +33,17 @@ class LogPanel extends StatefulWidget {
 }
 
 class _LogPanelState extends State<LogPanel> {
+  static const _filters = [
+    (LogLevel.info, 'All', 'Every entry'),
+    (LogLevel.warn, 'Warnings', 'Warnings and errors'),
+    (LogLevel.error, 'Errors', 'Errors only'),
+  ];
+
   LogLevel _min = LogLevel.info;
 
   AppLog get _log => widget.log ?? appLog;
 
-  Future<void> _copy() async {
-    final n = _log.atLeast(_min).length;
+  Future<void> _copy(int n) async {
     await Clipboard.setData(ClipboardData(text: _log.asText(min: _min)));
     if (!mounted) return;
     ScaffoldMessenger.maybeOf(context)?.showSnackBar(
@@ -58,7 +56,7 @@ class _LogPanelState extends State<LogPanel> {
 
   @override
   Widget build(BuildContext context) {
-    final look = _Look.of(context);
+    final look = _lookOf(context);
     return Material(
       color: look.surface,
       elevation: 12,
@@ -71,23 +69,24 @@ class _LogPanelState extends State<LogPanel> {
         child: ListenableBuilder(
           listenable: _log,
           builder: (context, _) {
-            final all = _log.entries;
-            final shown = _log.atLeast(_min);
+            final total = _log.entries.length;
+            final shown = _log.atLeast(_min).reversed.toList();
+            final empty = total == 0
+                ? 'Nothing logged yet'
+                : _min == LogLevel.warn
+                ? 'No warnings or errors'
+                : 'No errors';
             return Column(
               crossAxisAlignment: CrossAxisAlignment.stretch,
               children: [
-                _header(look, all.length, shown.length),
+                _header(look, total, shown.length),
                 Divider(height: 9, color: look.border),
                 Expanded(
                   child: shown.isEmpty
                       ? Center(
                           child: Text(
-                            all.isEmpty
-                                ? 'Nothing logged yet'
-                                : _min == LogLevel.warn
-                                ? 'No warnings or errors'
-                                : 'No errors',
-                            style: look.body.copyWith(color: look.label),
+                            empty,
+                            style: look.body.copyWith(color: look.muted),
                           ),
                         )
                       : _list(context, look, shown),
@@ -101,13 +100,24 @@ class _LogPanelState extends State<LogPanel> {
   }
 
   Widget _header(_Look look, int total, int shown) {
-    final dropped = _log.dropped;
     final count = [
-      _min == LogLevel.info
-          ? '$total entr${total == 1 ? 'y' : 'ies'}'
-          : '$shown of $total',
-      if (dropped > 0) '$dropped older dropped',
+      if (_min == LogLevel.info)
+        '$total entr${total == 1 ? 'y' : 'ies'}'
+      else
+        '$shown of $total',
+      if (_log.dropped > 0) '${_log.dropped} older dropped',
     ].join(' · ');
+    Widget button(String id, IconData icon, String tip, VoidCallback? f) =>
+        IconButton(
+          key: ValueKey(id),
+          tooltip: tip,
+          iconSize: 16,
+          color: look.text,
+          disabledColor: look.disabled,
+          visualDensity: VisualDensity.compact,
+          onPressed: f,
+          icon: Icon(icon),
+        );
     return Row(
       children: [
         Text(
@@ -115,7 +125,7 @@ class _LogPanelState extends State<LogPanel> {
           style: look.body.copyWith(
             fontSize: 13,
             fontWeight: FontWeight.bold,
-            color: look.title,
+            color: look.accent,
           ),
         ),
         const SizedBox(width: 10),
@@ -125,240 +135,29 @@ class _LogPanelState extends State<LogPanel> {
             key: const ValueKey('log-count'),
             maxLines: 1,
             overflow: TextOverflow.ellipsis,
-            style: look.body.copyWith(color: look.label),
+            style: look.body.copyWith(color: look.muted),
           ),
         ),
-        _Filter(
-          look: look,
-          value: _min,
-          onChanged: (l) => setState(() => _min = l),
-        ),
+        _filter(look),
         const SizedBox(width: 8),
-        _HeaderButton(
-          look: look,
-          id: 'log-copy',
-          icon: Icons.copy,
-          tooltip: 'Copy the entries shown',
-          onPressed: shown == 0 ? null : _copy,
+        button(
+          'log-copy',
+          Icons.copy,
+          'Copy the entries shown',
+          shown == 0 ? null : () => _copy(shown),
         ),
-        _HeaderButton(
-          look: look,
-          id: 'log-clear',
-          icon: Icons.delete_outline,
-          tooltip: 'Clear the log',
-          onPressed: total == 0 ? null : _log.clear,
-        ),
-        _HeaderButton(
-          look: look,
-          id: 'log-close',
-          icon: Icons.close,
-          tooltip: 'Close',
-          onPressed: widget.onClose,
+        button(
+          'log-clear',
+          Icons.delete_outline,
+          'Clear the log',
+          total == 0 ? null : _log.clear,
         ),
+        button('log-close', Icons.close, 'Close', widget.onClose),
       ],
     );
   }
 
-  /// Newest first; time, level and source in columns as wide as their
-  /// widest text, the message wrapping beside them.
-  Widget _list(BuildContext context, _Look look, List<LogEntry> shown) {
-    final scaler = MediaQuery.textScalerOf(context);
-    double width(String text) {
-      final p = TextPainter(
-        text: TextSpan(text: text, style: look.body),
-        textDirection: TextDirection.ltr,
-        textScaler: scaler,
-        maxLines: 1,
-      )..layout();
-      final w = p.width;
-      p.dispose();
-      return w.ceilToDouble();
-    }
-
-    final sources = {for (final e in shown) e.source};
-    final columns = (
-      time: width('00:00:00.000'),
-      level: width(LogLevel.error.tag),
-      source: sources.map(width).fold<double>(0, math.max),
-    );
-    return ListView.builder(
-      key: const ValueKey('log-list'),
-      itemCount: shown.length,
-      itemBuilder: (context, i) => _EntryRow(
-        look: look,
-        entry: shown[shown.length - 1 - i],
-        columns: columns,
-      ),
-    );
-  }
-}
-
-/// The panel's colours and text style: the Bison tokens when the theme
-/// carries them, else the Material colour scheme.
-class _Look {
-  const _Look({
-    required this.surface,
-    required this.border,
-    required this.title,
-    required this.text,
-    required this.muted,
-    required this.label,
-    required this.source,
-    required this.warn,
-    required this.error,
-    required this.selected,
-    required this.disabled,
-    required this.body,
-  });
-
-  factory _Look.of(BuildContext context) {
-    final theme = Theme.of(context);
-    final typography = theme.extension<BisonTypographyTokens>();
-    final body =
-        (typography?.bodySmall ??
-                theme.textTheme.bodySmall ??
-                const TextStyle())
-            .copyWith(
-              fontSize: 11,
-              fontFeatures: const [FontFeature.tabularFigures()],
-            );
-    final t = theme.extension<BisonThemeTokens>();
-    if (t != null) {
-      return _Look(
-        surface: t.surfaceDefault,
-        border: t.borderPlain,
-        title: t.textPrimary,
-        text: t.textPlain,
-        muted: t.textMuted,
-        label: t.textSecondary,
-        source: t.textPrimary,
-        warn: t.iconWarning,
-        error: t.textError,
-        selected: t.surfacePressed,
-        disabled: t.textDisabled,
-        body: body.copyWith(color: t.textPlain),
-      );
-    }
-    final s = theme.colorScheme;
-    return _Look(
-      surface: s.surface,
-      border: s.outlineVariant,
-      title: s.primary,
-      text: s.onSurface,
-      muted: s.onSurfaceVariant,
-      label: s.onSurfaceVariant,
-      source: s.primary,
-      warn: Colors.amber.shade700,
-      error: s.error,
-      selected: s.primary.withValues(alpha: 0.16),
-      disabled: s.onSurface.withValues(alpha: 0.38),
-      body: body.copyWith(color: s.onSurface),
-    );
-  }
-
-  final Color surface;
-  final Color border;
-  final Color title;
-  final Color text;
-  final Color muted;
-  final Color label;
-  final Color source;
-  final Color warn;
-  final Color error;
-  final Color selected;
-  final Color disabled;
-  final TextStyle body;
-
-  /// The colour an entry's level is drawn in.
-  Color level(LogLevel l) => switch (l) {
-    LogLevel.info => text,
-    LogLevel.warn => warn,
-    LogLevel.error => error,
-  };
-}
-
-/// One entry: `12:00:01.234  WARN  link  message…`.
-class _EntryRow extends StatelessWidget {
-  const _EntryRow({
-    required this.look,
-    required this.entry,
-    required this.columns,
-  });
-
-  final _Look look;
-  final LogEntry entry;
-  final ({double time, double level, double source}) columns;
-
-  @override
-  Widget build(BuildContext context) {
-    const gap = SizedBox(width: 8);
-    return Padding(
-      padding: const EdgeInsets.symmetric(vertical: 1.5),
-      child: Row(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          SizedBox(
-            width: columns.time,
-            child: Text(
-              logClock(entry.time),
-              style: look.body.copyWith(color: look.muted),
-            ),
-          ),
-          gap,
-          SizedBox(
-            width: columns.level,
-            child: Text(
-              entry.level.tag,
-              style: look.body.copyWith(
-                color: look.level(entry.level),
-                fontWeight: entry.level == LogLevel.info
-                    ? FontWeight.normal
-                    : FontWeight.bold,
-              ),
-            ),
-          ),
-          gap,
-          SizedBox(
-            width: columns.source,
-            child: Text(
-              entry.source,
-              style: look.body.copyWith(color: look.source),
-            ),
-          ),
-          gap,
-          Expanded(child: Text(entry.message, style: look.body)),
-        ],
-      ),
-    );
-  }
-}
-
-/// All · Warnings · Errors, joined.
-class _Filter extends StatelessWidget {
-  const _Filter({
-    required this.look,
-    required this.value,
-    required this.onChanged,
-  });
-
-  final _Look look;
-  final LogLevel value;
-  final ValueChanged<LogLevel> onChanged;
-
-  static String _label(LogLevel l) => switch (l) {
-    LogLevel.info => 'All',
-    LogLevel.warn => 'Warnings',
-    LogLevel.error => 'Errors',
-  };
-
-  static String _tip(LogLevel l) => switch (l) {
-    LogLevel.info => 'every entry',
-    LogLevel.warn => 'warnings and errors',
-    LogLevel.error => 'errors only',
-  };
-
-  @override
-  Widget build(BuildContext context) => Container(
+  Widget _filter(_Look look) => Container(
     height: 24,
     decoration: BoxDecoration(
       border: Border.all(color: look.border),
@@ -368,21 +167,21 @@ class _Filter extends StatelessWidget {
     child: Row(
       mainAxisSize: MainAxisSize.min,
       children: [
-        for (final l in LogLevel.values)
+        for (final (level, label, tip) in _filters)
           Tooltip(
-            message: _tip(l),
+            message: tip,
             child: InkWell(
-              key: ValueKey('log-filter-${l.name}'),
-              onTap: () => onChanged(l),
+              key: ValueKey('log-filter-${level.name}'),
+              onTap: () => setState(() => _min = level),
               child: Container(
-                color: l == value ? look.selected : null,
+                color: level == _min ? look.selected : null,
                 padding: const EdgeInsets.symmetric(horizontal: 8),
                 alignment: Alignment.center,
                 child: Text(
-                  _label(l),
+                  label,
                   style: look.body.copyWith(
                     fontWeight: FontWeight.w500,
-                    color: l == value ? look.title : look.text,
+                    color: level == _min ? look.accent : look.text,
                   ),
                 ),
               ),
@@ -391,33 +190,118 @@ class _Filter extends StatelessWidget {
       ],
     ),
   );
-}
 
-/// A small icon button for the header; its tooltip names it.
-class _HeaderButton extends StatelessWidget {
-  const _HeaderButton({
-    required this.look,
-    required this.id,
-    required this.icon,
-    required this.tooltip,
-    required this.onPressed,
-  });
+  /// Time, level and source columns sized to their widest text.
+  Widget _list(BuildContext context, _Look look, List<LogEntry> shown) {
+    final scaler = MediaQuery.textScalerOf(context);
+    double width(String text) {
+      final p = TextPainter(
+        text: TextSpan(text: text, style: look.body),
+        textDirection: TextDirection.ltr,
+        textScaler: scaler,
+      )..layout();
+      final w = p.width.ceilToDouble();
+      p.dispose();
+      return w;
+    }
 
-  final _Look look;
-  final String id;
-  final IconData icon;
-  final String tooltip;
-  final VoidCallback? onPressed;
+    final time = width('00:00:00.000');
+    final level = width(LogLevel.error.tag);
+    final source = {for (final e in shown) e.source}
+        .map(width)
+        .fold(0.0, math.max);
+    Widget cell(double w, String text, TextStyle style) => SizedBox(
+      width: w,
+      child: Text(text, style: style),
+    );
+    return ListView.builder(
+      key: const ValueKey('log-list'),
+      itemCount: shown.length,
+      itemBuilder: (context, i) {
+        final e = shown[i];
+        return Padding(
+          padding: const EdgeInsets.symmetric(vertical: 1.5),
+          child: Row(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            spacing: 8,
+            children: [
+              cell(
+                time,
+                logClock(e.time),
+                look.body.copyWith(color: look.muted),
+              ),
+              cell(
+                level,
+                e.level.tag,
+                look.body.copyWith(
+                  color: switch (e.level) {
+                    LogLevel.info => look.text,
+                    LogLevel.warn => look.warn,
+                    LogLevel.error => look.error,
+                  },
+                  fontWeight: e.level == LogLevel.info ? null : FontWeight.bold,
+                ),
+              ),
+              cell(source, e.source, look.body.copyWith(color: look.accent)),
+              Expanded(child: Text(e.message, style: look.body)),
+            ],
+          ),
+        );
+      },
+    );
+  }
+}
 
-  @override
-  Widget build(BuildContext context) => IconButton(
-    key: ValueKey(id),
-    tooltip: tooltip,
-    iconSize: 16,
-    color: look.text,
-    disabledColor: look.disabled,
-    visualDensity: VisualDensity.compact,
-    onPressed: onPressed,
-    icon: Icon(icon),
+typedef _Look = ({
+  Color surface,
+  Color border,
+  Color accent,
+  Color text,
+  Color muted,
+  Color warn,
+  Color error,
+  Color selected,
+  Color disabled,
+  TextStyle body,
+});
+
+/// Bison tokens when the theme has them, else the Material colour scheme.
+_Look _lookOf(BuildContext context) {
+  final theme = Theme.of(context);
+  final body =
+      (theme.extension<BisonTypographyTokens>()?.bodySmall ??
+              theme.textTheme.bodySmall ??
+              const TextStyle())
+          .copyWith(
+            fontSize: 11,
+            fontFeatures: const [FontFeature.tabularFigures()],
+          );
+  final t = theme.extension<BisonThemeTokens>();
+  if (t != null) {
+    return (
+      surface: t.surfaceDefault,
+      border: t.borderPlain,
+      accent: t.textPrimary,
+      text: t.textPlain,
+      muted: t.textSecondary,
+      warn: t.iconWarning,
+      error: t.textError,
+      selected: t.surfacePressed,
+      disabled: t.textDisabled,
+      body: body.copyWith(color: t.textPlain),
+    );
+  }
+  final s = theme.colorScheme;
+  return (
+    surface: s.surface,
+    border: s.outlineVariant,
+    accent: s.primary,
+    text: s.onSurface,
+    muted: s.onSurfaceVariant,
+    warn: Colors.amber.shade700,
+    error: s.error,
+    selected: s.primary.withValues(alpha: 0.16),
+    disabled: s.onSurface.withValues(alpha: 0.38),
+    body: body.copyWith(color: s.onSurface),
   );
 }

From 76663d5ff2d6a94187c450b61a6c370af81e72ea Mon Sep 17 00:00:00 2001
From: Robert Santucci <rsantucc@fnal.gov>
Date: Mon, 5 Oct 2026 09:27:35 -0500
Subject: [PATCH 4/6] LogPanel: one-line bison import

---
 lib/src/widgets/log_panel.dart | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/src/widgets/log_panel.dart b/lib/src/widgets/log_panel.dart
index 64ac586..f6a4c8f 100644
--- a/lib/src/widgets/log_panel.dart
+++ b/lib/src/widgets/log_panel.dart
@@ -4,8 +4,7 @@ library;
 
 import 'dart:math' as math;
 
-import 'package:bison_design_system/bison_design_system.dart'
-    show BisonThemeTokens, BisonTypographyTokens;
+import 'package:bison_design_system/bison_design_system.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart' show Clipboard, ClipboardData;
 

From d5de38a08a40d5f58a2265bb7a48f9dee6292bca Mon Sep 17 00:00:00 2001
From: Robert Santucci <rsantucc@fnal.gov>
Date: Mon, 5 Oct 2026 11:06:27 -0500
Subject: [PATCH 5/6] AppLog/LogPanel: review fixes

Cut messages by code point; Copy takes the entries shown; the filter
grows with text scale and announces its selection; the source column
is capped at 120 px and ellipsized.
---
 lib/src/logging/app_log.dart      |  6 ++-
 lib/src/widgets/log_panel.dart    | 69 +++++++++++++++++++------------
 test/unit_tests/app_log_test.dart |  2 +
 test/widget/log_panel_test.dart   | 47 +++++++++++++++++++++
 4 files changed, 96 insertions(+), 28 deletions(-)

diff --git a/lib/src/logging/app_log.dart b/lib/src/logging/app_log.dart
index 9258b91..6838835 100644
--- a/lib/src/logging/app_log.dart
+++ b/lib/src/logging/app_log.dart
@@ -63,7 +63,7 @@ class AppLog extends ChangeNotifier {
   bool mirror;
   final DateTime Function() now;
 
-  /// Longer messages are cut.
+  /// Longer messages are cut (in Unicode code points).
   static const int maxMessage = 1000;
   static final RegExp _breaks = RegExp(r'\s*[\r\n]+\s*');
 
@@ -85,7 +85,9 @@ class AppLog extends ChangeNotifier {
   /// Logs [message] on one line, cut to [maxMessage].
   LogEntry add(LogLevel level, String source, String message) {
     var m = message.replaceAll(_breaks, ' ');
-    if (m.length > maxMessage) m = '${m.substring(0, maxMessage)}…';
+    if (m.runes.length > maxMessage) {
+      m = '${String.fromCharCodes(m.runes.take(maxMessage))}…';
+    }
     final e = LogEntry(now(), level, source, m);
     if (_entries.length >= capacity) {
       _entries.removeFirst();
diff --git a/lib/src/widgets/log_panel.dart b/lib/src/widgets/log_panel.dart
index f6a4c8f..e5cdeef 100644
--- a/lib/src/widgets/log_panel.dart
+++ b/lib/src/widgets/log_panel.dart
@@ -38,12 +38,17 @@ class _LogPanelState extends State<LogPanel> {
     (LogLevel.error, 'Errors', 'Errors only'),
   ];
 
+  static const double _maxSource = 120;
+
   LogLevel _min = LogLevel.info;
 
   AppLog get _log => widget.log ?? appLog;
 
-  Future<void> _copy(int n) async {
-    await Clipboard.setData(ClipboardData(text: _log.asText(min: _min)));
+  /// Copies [shown] (newest first) oldest first: what the panel shows.
+  Future<void> _copy(List<LogEntry> shown) async {
+    final n = shown.length;
+    final text = shown.reversed.map((e) => e.line).join('\n');
+    await Clipboard.setData(ClipboardData(text: text));
     if (!mounted) return;
     ScaffoldMessenger.maybeOf(context)?.showSnackBar(
       SnackBar(
@@ -78,7 +83,7 @@ class _LogPanelState extends State<LogPanel> {
             return Column(
               crossAxisAlignment: CrossAxisAlignment.stretch,
               children: [
-                _header(look, total, shown.length),
+                _header(look, total, shown),
                 Divider(height: 9, color: look.border),
                 Expanded(
                   child: shown.isEmpty
@@ -98,12 +103,12 @@ class _LogPanelState extends State<LogPanel> {
     );
   }
 
-  Widget _header(_Look look, int total, int shown) {
+  Widget _header(_Look look, int total, List<LogEntry> shown) {
     final count = [
       if (_min == LogLevel.info)
         '$total entr${total == 1 ? 'y' : 'ies'}'
       else
-        '$shown of $total',
+        '${shown.length} of $total',
       if (_log.dropped > 0) '${_log.dropped} older dropped',
     ].join(' · ');
     Widget button(String id, IconData icon, String tip, VoidCallback? f) =>
@@ -143,7 +148,7 @@ class _LogPanelState extends State<LogPanel> {
           'log-copy',
           Icons.copy,
           'Copy the entries shown',
-          shown == 0 ? null : () => _copy(shown),
+          shown.isEmpty ? null : () => _copy(shown),
         ),
         button(
           'log-clear',
@@ -157,7 +162,7 @@ class _LogPanelState extends State<LogPanel> {
   }
 
   Widget _filter(_Look look) => Container(
-    height: 24,
+    constraints: const BoxConstraints(minHeight: 24),
     decoration: BoxDecoration(
       border: Border.all(color: look.border),
       borderRadius: BorderRadius.circular(3),
@@ -167,20 +172,24 @@ class _LogPanelState extends State<LogPanel> {
       mainAxisSize: MainAxisSize.min,
       children: [
         for (final (level, label, tip) in _filters)
-          Tooltip(
-            message: tip,
-            child: InkWell(
-              key: ValueKey('log-filter-${level.name}'),
-              onTap: () => setState(() => _min = level),
-              child: Container(
-                color: level == _min ? look.selected : null,
-                padding: const EdgeInsets.symmetric(horizontal: 8),
-                alignment: Alignment.center,
-                child: Text(
-                  label,
-                  style: look.body.copyWith(
-                    fontWeight: FontWeight.w500,
-                    color: level == _min ? look.accent : look.text,
+          Semantics(
+            button: true,
+            selected: level == _min,
+            child: Tooltip(
+              message: tip,
+              child: InkWell(
+                key: ValueKey('log-filter-${level.name}'),
+                onTap: () => setState(() => _min = level),
+                child: Container(
+                  color: level == _min ? look.selected : null,
+                  padding: const EdgeInsets.symmetric(horizontal: 8),
+                  alignment: Alignment.center,
+                  child: Text(
+                    label,
+                    style: look.body.copyWith(
+                      fontWeight: FontWeight.w500,
+                      color: level == _min ? look.accent : look.text,
+                    ),
                   ),
                 ),
               ),
@@ -190,7 +199,8 @@ class _LogPanelState extends State<LogPanel> {
     ),
   );
 
-  /// Time, level and source columns sized to their widest text.
+  /// Time, level and source columns sized to their widest text; the source
+  /// column at most [_maxSource] wide.
   Widget _list(BuildContext context, _Look look, List<LogEntry> shown) {
     final scaler = MediaQuery.textScalerOf(context);
     double width(String text) {
@@ -206,12 +216,19 @@ class _LogPanelState extends State<LogPanel> {
 
     final time = width('00:00:00.000');
     final level = width(LogLevel.error.tag);
-    final source = {for (final e in shown) e.source}
-        .map(width)
-        .fold(0.0, math.max);
+    final source = math.min(
+      _maxSource,
+      {for (final e in shown) e.source}.map(width).fold(0.0, math.max),
+    );
     Widget cell(double w, String text, TextStyle style) => SizedBox(
       width: w,
-      child: Text(text, style: style),
+      child: Text(
+        text,
+        style: style,
+        maxLines: 1,
+        softWrap: false,
+        overflow: TextOverflow.ellipsis,
+      ),
     );
     return ListView.builder(
       key: const ValueKey('log-list'),
diff --git a/test/unit_tests/app_log_test.dart b/test/unit_tests/app_log_test.dart
index 7022cdf..d6af7d8 100644
--- a/test/unit_tests/app_log_test.dart
+++ b/test/unit_tests/app_log_test.dart
@@ -85,6 +85,8 @@ void main() {
     log.info('link', 'x' * 5000);
     expect(log.entries.last.message, hasLength(AppLog.maxMessage + 1));
     expect(log.entries.last.message, endsWith('…'));
+    log.info('link', '${'a' * 999}😀😀');
+    expect(log.entries.last.message, '${'a' * 999}😀…', reason: 'whole emoji');
   });
 
   testWidgets('a burst of entries is one notification, at most every '
diff --git a/test/widget/log_panel_test.dart b/test/widget/log_panel_test.dart
index 5e5edee..0538ef2 100644
--- a/test/widget/log_panel_test.dart
+++ b/test/widget/log_panel_test.dart
@@ -108,6 +108,53 @@ void main() {
     log.dispose();
   });
 
+  testWidgets('Copy takes what is shown, not entries not yet drawn', (
+    tester,
+  ) async {
+    String? copied;
+    tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
+      SystemChannels.platform,
+      (call) async {
+        if (call.method == 'Clipboard.setData') {
+          copied = (call.arguments as Map)['text'] as String?;
+        }
+        return null;
+      },
+    );
+    final log = _filled();
+    await tester.pumpWidget(_host(log));
+    log.info('late', 'not drawn yet');
+    await tester.tap(find.byKey(const ValueKey('log-copy')));
+    await tester.pump();
+    expect(copied, isNot(contains('not drawn yet')));
+    await tester.pump(const Duration(milliseconds: 300));
+    log.dispose();
+  });
+
+  testWidgets('a long source is cut, not overflowing', (tester) async {
+    final log = _filled()..info('x' * 200, 'message');
+    await tester.pumpWidget(_host(log, width: 440));
+    expect(tester.takeException(), isNull);
+    expect(find.text('message'), findsOneWidget);
+    log.dispose();
+  });
+
+  testWidgets('the selected filter is announced', (tester) async {
+    final handle = tester.ensureSemantics();
+    final log = _filled();
+    await tester.pumpWidget(_host(log));
+    expect(
+      tester.getSemantics(find.byKey(const ValueKey('log-filter-info'))),
+      isSemantics(isSelected: true),
+    );
+    expect(
+      tester.getSemantics(find.byKey(const ValueKey('log-filter-error'))),
+      isNot(isSemantics(isSelected: true)),
+    );
+    log.dispose();
+    handle.dispose();
+  });
+
   testWidgets('works under a plain Material theme too', (tester) async {
     final log = _filled();
     await tester.pumpWidget(_host(log, theme: ThemeData.dark()));

From 2799ea4d427b105a8877140df28f7161d3dc920e Mon Sep 17 00:00:00 2001
From: Rich Neswold <neswold@fnal.gov>
Date: Fri, 9 Oct 2026 13:47:45 -0500
Subject: [PATCH 6/6] Bump version to 1.4.2

---
 pubspec.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pubspec.yaml b/pubspec.yaml
index 74cdc35..8381034 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: flutter_controls_core
 description: A Flutter package to write Fermilab applications.
-version: 1.4.0
+version: 1.4.2
 publish_to: none
 
 environment: