implemented recurrence exception (EXDATE) support for custom events, refactored timetable break and holiday generation logic, and refined RRule editor UI/theming and tile layouts

lib/view/pages/timetable/custom_events/custom_event_edit_dialog.dart

@@ -281,20 +281,15 @@ class _CustomEventEditDialogState extends State<CustomEventEditDialog> {
             ),
           ),
           const Divider(),
-          RRuleGenerator(
-            config: RRuleGeneratorConfig(
-              selectDayStyle: RRuleSelectDayStyle(
-                dayStyle: BoxDecoration(
-                  shape: BoxShape.circle,
-                  color: Theme.of(context).colorScheme.secondary,
-                ),
-                dayTextStyle: const TextStyle(color: Colors.black),
-                selectedDayStyle: BoxDecoration(
-                  shape: BoxShape.circle,
-                  color: Theme.of(context).primaryColor,
-                ),
-              ),
-            ),
+          // The RRuleGenerator widget has zero outer padding while every
+          // surrounding ListTile uses the default 16px horizontal indent.
+          // Wrap it to match — keeps the rule editor visually aligned with
+          // the date/time/color rows above instead of hugging the dialog
+          // border.
+          Padding(
+            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
+            child: RRuleGenerator(
+              config: _rruleConfig(context),
               initialRRule: _rrule,
               locale: RRuleLocale.de_DE,
               onChange: (newValue) {
@@ -302,6 +297,7 @@ class _CustomEventEditDialogState extends State<CustomEventEditDialog> {
                 setState(() => _rrule = newValue);
               },
             ),
+          ),
         ],
       ),
     ),
@@ -312,4 +308,69 @@ class _CustomEventEditDialogState extends State<CustomEventEditDialog> {
       ),
     ],
   );
+
+  /// Maps the rrule_generator widget onto Marianum's Material theme so its
+  /// pickers blend in with the rest of the form (the package's defaults
+  /// have an out-of-place red switch outline and bold ALL-CAPS-feeling
+  /// headers). Layout itself stays as the package provides — fully custom
+  /// styling beyond what `RRuleGeneratorConfig` exposes isn't possible
+  /// without forking it.
+  RRuleGeneratorConfig _rruleConfig(BuildContext context) {
+    final theme = Theme.of(context);
+    final cs = theme.colorScheme;
+    return RRuleGeneratorConfig(
+      headerStyle: RRuleHeaderStyle(
+        textStyle:
+            theme.textTheme.titleSmall?.copyWith(
+              fontWeight: FontWeight.w600,
+              color: cs.onSurface,
+            ) ??
+            const TextStyle(),
+      ),
+      labelStyle:
+          theme.textTheme.bodyMedium?.copyWith(color: cs.onSurfaceVariant) ??
+          const TextStyle(),
+      inputTextStyle: RRuleInputTextStyle(
+        inputTextDecoration: const InputDecoration(
+          isDense: true,
+          border: OutlineInputBorder(),
+        ),
+        inputTextStyle:
+            theme.textTheme.bodyMedium ?? const TextStyle(),
+      ),
+      dropdownStyle: RRuleDropdownStyle(
+        dropdownMenuTextStyle: theme.textTheme.bodyMedium ?? const TextStyle(),
+        dropdownMenuItemTextStyle:
+            theme.textTheme.bodyMedium ?? const TextStyle(),
+      ),
+      switchStyle: RRuleSwitchStyle(
+        thumbColor: cs.onPrimary,
+        activeTrackColor: cs.primary,
+        inactiveTrackColor: cs.surfaceContainerHighest,
+        trackOutlineWidth: 0,
+        trackOutlineColor: Colors.transparent,
+        switchTextStyle:
+            theme.textTheme.bodyMedium?.copyWith(
+              color: cs.onSurface,
+            ) ??
+            const TextStyle(),
+      ),
+      selectDayStyle: RRuleSelectDayStyle(
+        dayStyle: BoxDecoration(
+          shape: BoxShape.circle,
+          color: cs.surfaceContainerHighest,
+        ),
+        dayTextStyle: TextStyle(color: cs.onSurface),
+        selectedDayStyle: BoxDecoration(
+          shape: BoxShape.circle,
+          color: cs.primary,
+        ),
+        selectedDayTextStyle: TextStyle(color: cs.onPrimary),
+      ),
+      datePickerStyle: RRuleDatePickerStyle(
+        datePickerTextStyle: theme.textTheme.bodyMedium ?? const TextStyle(),
+      ),
+      divider: const Divider(height: 1),
+    );
+  }
 }

lib/view/pages/timetable/data/calendar_logic.dart

@@ -106,10 +106,21 @@ partitionAppointmentsForWeek(
       final parsed = RecurrenceRule.fromString(rule);
       final anchorUtc = a.startTime.toUtc();
       final duration = a.endTime.difference(a.startTime);
+      // Day-keyed set of exception dates so occurrences scheduled for one
+      // of them get skipped. Syncfusion's own recurrenceExceptionDates
+      // handling never runs because we expand the rule manually here.
+      final exceptionDayKeys = (a.recurrenceExceptionDates ?? const <DateTime>[])
+          .map((d) => '${d.year}-${d.month}-${d.day}')
+          .toSet();
       for (final occUtc in parsed.getInstances(start: anchorUtc)) {
         if (!occUtc.isBefore(weekEndUtc)) break;
         if (occUtc.isBefore(weekStartUtc)) continue;
         final occLocal = occUtc.toLocal();
+        if (exceptionDayKeys.contains(
+          '${occLocal.year}-${occLocal.month}-${occLocal.day}',
+        )) {
+          continue;
+        }
         final idx = DateTime(
           occLocal.year,
           occLocal.month,

lib/view/pages/timetable/data/rrule_with_exceptions.dart

@@ -0,0 +1,57 @@
+/// Parses recurrence-rule strings produced by the `rrule_generator` widget
+/// into a clean RRULE plus a separate list of exception dates.
+///
+/// `rrule_generator` appends excluded dates as `;EXDATE=20260514T000000,...`
+/// to the rule string, which is **not** valid iCalendar — `EXDATE` is its
+/// own property, not an RRULE parameter. Anything reading the raw string
+/// with a strict parser (Syncfusion, package:rrule) silently drops the
+/// EXDATE bit, so exclusions never apply. Split the two here.
+class ParsedRRule {
+  final String rule;
+  final List<DateTime> exceptions;
+  const ParsedRRule({required this.rule, required this.exceptions});
+
+  static const empty = ParsedRRule(rule: '', exceptions: []);
+}
+
+ParsedRRule parseRRuleWithExceptions(String input) {
+  if (input.isEmpty) return ParsedRRule.empty;
+  final match = RegExp(r';EXDATE=([^;]+)$').firstMatch(input);
+  final exceptions = match == null
+      ? const <DateTime>[]
+      : match
+            .group(1)!
+            .split(',')
+            .map(_parseExdate)
+            .whereType<DateTime>()
+            .toList();
+  // Keep the rule string as-is (still has its `RRULE:` content-line prefix
+  // when present). Both Syncfusion's `Appointment.recurrenceRule` and
+  // `package:rrule`'s `RecurrenceRule.fromString` parse it correctly with
+  // the prefix; stripping it was a regression that confused Syncfusion's
+  // weekly BYDAY decoder on multi-day rules.
+  final rule = match == null ? input : input.substring(0, match.start);
+  return ParsedRRule(rule: rule, exceptions: exceptions);
+}
+
+/// Parses one `yyyyMMddTHHmmss` chunk into a local-time [DateTime].
+DateTime? _parseExdate(String s) {
+  if (s.length < 15 || s[8] != 'T') return null;
+  final year = int.tryParse(s.substring(0, 4));
+  final month = int.tryParse(s.substring(4, 6));
+  final day = int.tryParse(s.substring(6, 8));
+  final hour = int.tryParse(s.substring(9, 11));
+  final minute = int.tryParse(s.substring(11, 13));
+  final second = int.tryParse(s.substring(13, 15));
+  if ([
+    year,
+    month,
+    day,
+    hour,
+    minute,
+    second,
+  ].any((e) => e == null)) {
+    return null;
+  }
+  return DateTime(year!, month!, day!, hour!, minute!, second!);
+}

lib/view/pages/timetable/data/timetable_appointment_factory.dart

@@ -10,6 +10,7 @@ import '../custom_events/custom_event_colors.dart';
 import 'arbitrary_appointment.dart';
 import 'lesson_color.dart';
 import 'lesson_status.dart';
+import 'rrule_with_exceptions.dart';
 import 'timetable_name_mode.dart';
 import 'webuntis_time.dart';
 
@@ -81,6 +82,23 @@ class TimetableAppointmentFactory {
 
   Appointment _customEventToAppointment(CustomTimetableEvent event) {
     final allDay = isCustomEventAllDay(event);
+    // rrule_generator stores excluded dates as a non-standard ";EXDATE=..."
+    // suffix on the rule string. Strip it and feed the dates separately —
+    // Syncfusion matches recurrence exceptions through this property, not
+    // through anything inside `recurrenceRule`.
+    final parsed = parseRRuleWithExceptions(event.rrule);
+    final exceptionDates = parsed.exceptions
+        .map(
+          (d) => DateTime(
+            d.year,
+            d.month,
+            d.day,
+            event.startDate.hour,
+            event.startDate.minute,
+            event.startDate.second,
+          ),
+        )
+        .toList();
     return Appointment(
       id: CustomAppointment(event),
       startTime: event.startDate,
@@ -101,7 +119,8 @@ class TimetableAppointmentFactory {
           ? null
           : event.description.trim(),
       subject: _collapseWhitespace(event.title) ?? event.title,
-      recurrenceRule: event.rrule,
+      recurrenceRule: parsed.rule,
+      recurrenceExceptionDates: exceptionDates.isEmpty ? null : exceptionDates,
       color: TimetableColors.getColorFromString(
         event.color ?? TimetableColors.defaultColor.name,
       ),

lib/view/pages/timetable/details/custom_event_sheet.dart

@@ -7,6 +7,7 @@ import '../../../../widget/centered_leading.dart';
 import '../../../../widget/debug/debug_tile.dart';
 import '../../../../widget/details_bottom_sheet.dart';
 import '../custom_events/custom_event_edit_dialog.dart';
+import '../data/rrule_with_exceptions.dart';
 import 'delete_custom_event.dart';
 
 class CustomEventSheet {
@@ -78,7 +79,13 @@ class CustomEventSheet {
                 return const Text('Keine weiteren Vorkommnisse');
               }
               if (snapshot.data == null) return const Text('...');
-              final rrule = RecurrenceRule.fromString(event.rrule);
+              // Strip the rrule_generator-specific `;EXDATE=…` suffix
+              // first — `package:rrule` is strict and throws on it.
+              final parsed = parseRRuleWithExceptions(event.rrule);
+              if (parsed.rule.isEmpty) {
+                return const Text('Keine weiteren Vorkommnisse');
+              }
+              final rrule = RecurrenceRule.fromString(parsed.rule);
               if (!rrule.canFullyConvertToText) {
                 return const Text('Keine genauere Angabe möglich.');
               }

lib/view/pages/timetable/widgets/appointment_tile.dart

@@ -106,11 +106,10 @@ class _TileContent extends StatelessWidget {
 
         if (isCustom) {
           if (description.isEmpty || bodyLineCapacity <= 0) {
-            return Column(
-              crossAxisAlignment: CrossAxisAlignment.stretch,
-              mainAxisSize: MainAxisSize.min,
-              children: [titleWidget],
-            );
+            // Explicit height + FittedBox in the title keeps a too-tall
+            // intrinsic title (full font size > min-font-line-height) from
+            // overflowing the tile by a couple of pixels.
+            return SizedBox(height: titleLineHeight, child: titleWidget);
           }
           return Column(
             crossAxisAlignment: CrossAxisAlignment.stretch,

lib/view/pages/timetable/widgets/special_regions_builder.dart

@@ -22,36 +22,56 @@ class SpecialRegionsBuilder {
   });
 
   List<TimeRegion> build() {
-    final lastMonday = DateTime.now()
+    final rangeStart = DateTime.now()
         .subtract(const Duration(days: 14))
         .nextWeekday(DateTime.monday);
+    // Far enough out to cover comfortable scrolling without rebuilding;
+    // Syncfusion only paints regions that intersect the visible window so
+    // the extra entries don't hurt rendering cost.
+    final rangeEnd = DateTime.now().add(const Duration(days: 180));
 
     final holidayRegions = _buildHolidayRegions().toList();
-    bool isInHoliday(DateTime time) =>
-        holidayRegions.any((region) => region.startTime.isSameDay(time));
+    final holidayDays = holidayRegions
+        .map((r) => _dayKey(r.startTime))
+        .toSet();
 
-    final breakRegions = schedule.periods
-        .where((p) => p.isBreak)
-        .map((p) {
-          final start = lastMonday.copyWith(
+    // Materialise one TimeRegion per break per non-holiday day. Tried
+    // `recurrenceRule: FREQ=DAILY` with `recurrenceExceptionDates` first,
+    // but Syncfusion's recurrence exception matching is unreliable in
+    // practice — the break overlay kept showing on holiday days. Generating
+    // explicit per-day regions and just skipping holidays is robust.
+    final breakPeriods = schedule.periods.where((p) => p.isBreak).toList();
+    final breakRegions = <TimeRegion>[];
+    for (
+      var day = rangeStart;
+      !day.isAfter(rangeEnd);
+      day = day.add(const Duration(days: 1))
+    ) {
+      if (holidayDays.contains(_dayKey(day))) continue;
+      for (final p in breakPeriods) {
+        final start = day.copyWith(
           hour: p.start.hour,
           minute: p.start.minute,
         );
-          return _breakRegion(start, p.duration);
-        })
-        .where((region) => !isInHoliday(region.startTime));
+        breakRegions.add(_breakRegion(start, p.duration));
+      }
+    }
 
     return [...holidayRegions, ...breakRegions];
   }
 
+  static String _dayKey(DateTime d) => '${d.year}-${d.month}-${d.day}';
+
   Iterable<TimeRegion> _buildHolidayRegions() => holidays.result.expand((
     holiday,
   ) {
     final startDay = WebuntisTime.parse(holiday.startDate, 0);
-    final dayCount = WebuntisTime.parse(
-      holiday.endDate,
-      0,
-    ).difference(startDay).inDays;
+    final endDay = WebuntisTime.parse(holiday.endDate, 0);
+    // Webuntis treats endDate inclusively (last day of the break) — the
+    // `+ 1` covers single-day public holidays (where startDate == endDate)
+    // and the final day of a multi-day vacation, both of which would
+    // otherwise be skipped.
+    final dayCount = endDay.difference(startDay).inDays + 1;
     final days = List<DateTime>.generate(
       dayCount,
       (i) => startDay.add(Duration(days: i)),
@@ -66,7 +86,6 @@ class SpecialRegionsBuilder {
         endTime: day.copyWith(hour: gridEndHour, minute: gridEndMinute),
         text: '$kTimeRegionHolidayPrefix${holiday.name}',
         color: disabledColor.withAlpha(50),
-        iconData: Icons.holiday_village_outlined,
       ),
     );
   });
@@ -74,7 +93,6 @@ class SpecialRegionsBuilder {
   TimeRegion _breakRegion(DateTime start, Duration duration) => TimeRegion(
     startTime: start,
     endTime: start.add(duration),
-    recurrenceRule: 'FREQ=DAILY;INTERVAL=1',
     text: kTimeRegionCenterIcon,
     color: colorScheme.primary.withAlpha(50),
     iconData: Icons.restaurant,

lib/view/pages/timetable/widgets/time_region_tile.dart

@@ -33,9 +33,10 @@ class TimeRegionTile extends StatelessWidget {
         child: Column(
           children: [
             const SizedBox(height: 15),
-            const Icon(Icons.cake),
-            const Text('FREI'),
-            const SizedBox(height: 10),
+            Icon(region.iconData ?? Icons.event_outlined),
+            const SizedBox(height: 5),
+            const Text('Schulfrei'),
+            const SizedBox(height: 15),
             RotatedBox(
               quarterTurns: 1,
               child: Text(