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/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(
-            hour: p.start.hour,
-            minute: p.start.minute,
-          );
-          return _breakRegion(start, p.duration);
-        })
-        .where((region) => !isInHoliday(region.startTime));
+    // 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,
+        );
+        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,