feat: add YaruCalendar

Author: Jupi007

example/lib/example_page_items.dart

@@ -6,6 +6,7 @@ import 'code_snippet_button.dart';
 import 'pages/autocomplete_page.dart';
 import 'pages/banner_page.dart';
 import 'pages/border_container_page.dart';
+import 'pages/calendar_page.dart';
 import 'pages/carousel_page.dart';
 import 'pages/checkbox_page.dart';
 import 'pages/choice_chip_bar_page.dart';
@@ -143,6 +144,14 @@ final examplePageItems = <PageItem>[
         ? const Icon(YaruIcons.calendar_month_filled)
         : const Icon(YaruIcons.calendar_month),
   ),
+  PageItem(
+    title: 'YaruCalendar',
+    floatingActionButtonBuilder: null,
+    pageBuilder: (context) => const CalendarPage(),
+    iconBuilder: (context, selected) => selected
+        ? const Icon(YaruIcons.calendar_month_filled)
+        : const Icon(YaruIcons.calendar_month),
+  ),
   PageItem(
     title: 'YaruDraggable',
     floatingActionButtonBuilder: (_) => const CodeSnippedButton(

example/lib/pages/calendar_page.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+import 'package:yaru/yaru.dart';
+
+class CalendarPage extends StatefulWidget {
+  const CalendarPage({super.key});
+
+  @override
+  State<CalendarPage> createState() => _CalendarPageState();
+}
+
+class _CalendarPageState extends State<CalendarPage> {
+  DateTime selectedDateTime = DateTime.now();
+
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          YaruDayPicker(
+            firstDate: DateTime(1900),
+            lastDate: DateTime(2100),
+            initialDate: DateTime.now(),
+            onDaySelected: (day) => setState(() => selectedDateTime = day),
+          ),
+          Text('Selected day: ${selectedDateTime.toString()}'),
+        ].withSpacing(25),
+      ),
+    );
+  }
+}
+
+extension _ListSpacing on List<Widget> {
+  List<Widget> withSpacing(double spacing) {
+    return expand((item) sync* {
+      yield SizedBox(height: spacing);
+      yield item;
+    }).skip(1).toList();
+  }
+}

lib/src/foundation/yaru_entry_segment.dart

@@ -7,7 +7,7 @@ enum YaruSegmentEventReturnAction {
   ignored,
 }
 
-abstract interface class YaruEntrySegment implements Listenable {
+abstract interface class YaruEntrySegment implements ChangeNotifier {
   String? get input;
   String get text;
   int get length;
@@ -396,7 +396,8 @@ class YaruSegmentedEntryController extends ChangeNotifier {
   /// Returns true if successful.
   bool maybeSelectPreviousSegment() {
     if (_index - 1 >= 0) {
-      index--;
+      _index--;
+      notifyListeners();
       return true;
     }
     return false;
@@ -406,20 +407,23 @@ class YaruSegmentedEntryController extends ChangeNotifier {
   /// Returns true if successful.
   bool maybeSelectNextSegment() {
     if (_index + 1 < length) {
-      index++;
+      _index++;
+      notifyListeners();
       return true;
     }
     return false;
   }
 
   /// Selects the first segment.
   void selectFirstSegment() {
-    index = 0;
+    _index = 0;
+    notifyListeners();
   }
 
   /// Selects the last segment.
   void selectLastSegment() {
-    index = length - 1;
+    _index = length - 1;
+    notifyListeners();
   }
 }