added an overlay based date time picker

example/lib/main.dart

@@ -16,13 +16,13 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'Demo drag down date time picker',
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
       home: Scaffold(
         appBar: AppBar(
-          title: const Text('Roster'),
+          title: const Text('Demo'),
         ),
         body: const DatePickerDemo(),
       ),
@@ -34,32 +34,95 @@ class DatePickerDemo extends StatelessWidget {
   const DatePickerDemo({Key? key}) : super(key: key);
   @override
   Widget build(BuildContext context) {
-    return DateTimePicker(
-      dateTimePickerTheme: const DateTimePickerTheme(
-        backgroundColor: Colors.white,
-        markedIndicatorColor: Colors.red,
-        baseTheme: DateBoxBaseTheme(
-          Colors.white,
-          TextStyle(color: Colors.black),
-        ),
-        selectedTheme: DateBoxSelectedTheme(
-          Color(0x4BF44336),
-          TextStyle(
-            color: Colors.red,
-          ),
-        ),
-        highlightTheme: DateBoxHighlightTheme(
-          Colors.red,
-          TextStyle(
-            color: Colors.white,
-          ),
-        ),
-        barTheme: DateTimePickerBarTheme(
-          barColor: Colors.black,
-          barOpacity: 1,
+    const dateTimePickerTheme = DateTimePickerTheme(
+      dateBoxShape: DateBoxShape.roundedRectangle,
+      backgroundColor: Colors.white,
+      markedIndicatorColor: Colors.red,
+      baseTheme: DateBoxBaseTheme(
+        Colors.white,
+        TextStyle(color: Colors.black),
+      ),
+      selectedTheme: DateBoxSelectedTheme(
+        Color(0x4BF44336),
+        TextStyle(
+          color: Colors.red,
         ),
       ),
-      markedDates: [DateTime(2022, 9, 6)],
+      highlightTheme: DateBoxHighlightTheme(
+        Colors.red,
+        TextStyle(
+          color: Colors.white,
+        ),
+      ),
+      barTheme: DateTimePickerBarTheme(
+        barColor: Colors.black,
+        barOpacity: 1,
+      ),
+    );
+
+    return Stack(
+      children: [
+        Center(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+            children: [
+              OverlayDateTimePicker(
+                theme: dateTimePickerTheme,
+                alignment: Alignment.bottomCenter,
+                child: const Text("Select Day"),
+                onTapDay: (date) {},
+              ),
+              OverlayDateTimePicker(
+                theme: dateTimePickerTheme,
+                alignment: Alignment.center,
+                buttonBuilder: (key, onPressed) => TextButton(
+                  key: key,
+                  onPressed: onPressed,
+                  child: const Text("Select Day"),
+                ),
+              ),
+              OverlayDateTimePicker(
+                theme: dateTimePickerTheme,
+                alignment: Alignment.topCenter,
+                buttonBuilder: (key, onPressed) => IconButton(
+                  key: key,
+                  onPressed: onPressed,
+                  icon: const Icon(
+                    Icons.schedule,
+                  ),
+                ),
+              )
+            ],
+          ),
+        ),
+        DragDownDateTimePicker(
+          dateTimePickerTheme: const DateTimePickerTheme(
+            backgroundColor: Colors.white,
+            markedIndicatorColor: Colors.red,
+            baseTheme: DateBoxBaseTheme(
+              Colors.white,
+              TextStyle(color: Colors.black),
+            ),
+            selectedTheme: DateBoxSelectedTheme(
+              Color(0x4BF44336),
+              TextStyle(
+                color: Colors.red,
+              ),
+            ),
+            highlightTheme: DateBoxHighlightTheme(
+              Colors.red,
+              TextStyle(
+                color: Colors.white,
+              ),
+            ),
+            barTheme: DateTimePickerBarTheme(
+              barColor: Colors.black,
+              barOpacity: 1,
+            ),
+          ),
+          markedDates: [DateTime(2022, 9, 6)],
+        )
+      ],
     );
   }
 }

example/web/index.html

@@ -1,58 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-  <!--
-    If you are serving your web app in a path other than the root, change the
-    href value below to reflect the base path you are serving from.
-
-    The path provided below has to start and end with a slash "/" in order for
-    it to work correctly.
-
-    For more details:
-    * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
-
-    This is a placeholder for base href that will be replaced by the value of
-    the `--base-href` argument provided to `flutter build`.
-  -->
-  <base href="$FLUTTER_BASE_HREF">
-
-  <meta charset="UTF-8">
-  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
-  <meta name="description" content="A new Flutter project.">
-
-  <!-- iOS meta tags & icons -->
-  <meta name="apple-mobile-web-app-capable" content="yes">
-  <meta name="apple-mobile-web-app-status-bar-style" content="black">
-  <meta name="apple-mobile-web-app-title" content="example">
-  <link rel="apple-touch-icon" href="icons/Icon-192.png">
-
-  <!-- Favicon -->
-  <link rel="icon" type="image/png" href="favicon.png"/>
-
-  <title>example</title>
-  <link rel="manifest" href="manifest.json">
-
-  <script>
-    // The value below is injected by flutter build, do not touch.
-    var serviceWorkerVersion = null;
-  </script>
-  <!-- This script adds the flutter initialization JS code -->
-  <script src="flutter.js" defer></script>
-</head>
-<body>
-  <script>
-    window.addEventListener('load', function(ev) {
-      // Download main.dart.js
-      _flutter.loader.loadEntrypoint({
-        serviceWorker: {
-          serviceWorkerVersion: serviceWorkerVersion,
-        }
-      }).then(function(engineInitializer) {
-        return engineInitializer.initializeEngine();
-      }).then(function(appRunner) {
-        return appRunner.runApp();
-      });
-    });
-  </script>
-</body>
-</html>

example/web/manifest.json

@@ -1,35 +0,0 @@
-{
-    "name": "example",
-    "short_name": "example",
-    "start_url": ".",
-    "display": "standalone",
-    "background_color": "#0175C2",
-    "theme_color": "#0175C2",
-    "description": "A new Flutter project.",
-    "orientation": "portrait-primary",
-    "prefer_related_applications": false,
-    "icons": [
-        {
-            "src": "icons/Icon-192.png",
-            "sizes": "192x192",
-            "type": "image/png"
-        },
-        {
-            "src": "icons/Icon-512.png",
-            "sizes": "512x512",
-            "type": "image/png"
-        },
-        {
-            "src": "icons/Icon-maskable-192.png",
-            "sizes": "192x192",
-            "type": "image/png",
-            "purpose": "maskable"
-        },
-        {
-            "src": "icons/Icon-maskable-512.png",
-            "sizes": "512x512",
-            "type": "image/png",
-            "purpose": "maskable"
-        }
-    ]
-}

lib/flutter_date_time_picker.dart

@@ -4,7 +4,8 @@
 
 library flutter_date_time_picker;
 
-export 'src/date_time_picker.dart' show DateTimePicker;
+export 'src/drag_down_date_time_picker.dart' show DragDownDateTimePicker;
+export 'src/overlay_date_time_picker.dart' show OverlayDateTimePicker;
 export 'src/enums/date_box_shape.dart';
 export 'src/models/date_box_base_theme.dart';
 export 'src/models/date_box_disabled_theme.dart';

lib/src/drag_down_date_time_picker.dart

@@ -11,7 +11,7 @@ import 'package:flutter_date_time_picker/src/widgets/month_date_time_picker/mont
 import 'package:flutter_date_time_picker/src/widgets/week_date_time_picker/week_date_time_picker_sheet.dart';
 import 'package:intl/date_symbol_data_local.dart';
 
-class DateTimePicker extends StatefulWidget {
+class DragDownDateTimePicker extends StatefulWidget {
   /// A widget that displays a date picker from a sheet form the top of the screen.
   /// This sheet displays initially displays a week but can be dragged down to show a full month.
   /// Both views can be dragged sideways to show the next or previous week/month.
@@ -37,7 +37,7 @@ class DateTimePicker extends StatefulWidget {
   ///     child: ListBody(
   ///     children: const <Widget>[
   ///     Text(
-  ///       'The time you try to choose is diabled, try to pick another time.'),
+  ///       'The time you try to choose is disabled, try to pick another time.'),
   ///     ],
   ///    ),
   ///   ),
@@ -112,7 +112,7 @@ class DateTimePicker extends StatefulWidget {
   ///   ),
   /// ),
   ///```
-  DateTimePicker({
+  DragDownDateTimePicker({
     this.dateTimePickerTheme = const DateTimePickerTheme(),
     this.header,
     this.onTapDay,
@@ -136,29 +136,29 @@ class DateTimePicker extends StatefulWidget {
   /// A [Widget] to display when the user picks a disabled time in the [TimePickerDialog]
   final Widget? wrongTimeDialog;
 
-  /// Visual properties for the [DateTimePicker]
+  /// Visual properties for the [DragDownDateTimePicker]
   final DateTimePickerTheme dateTimePickerTheme;
 
-  /// Widget shown at the top of the [DateTimePicker]
+  /// Widget shown at the top of the [DragDownDateTimePicker]
   final Widget? header;
 
   /// Callback that provides the date tapped on as a [DateTime] object.
   final Function(DateTime)? onTapDay;
 
-  /// Whether the current day should be highlighted in the [DateTimePicker]
+  /// Whether the current day should be highlighted in the [DragDownDateTimePicker]
   final bool highlightToday;
 
   /// a [bool] to set de clock on [TimePickerDialog] to a fixed 24 or 12-hour format.
   /// By default this gets determined by the [Locale] on the device.
   late final bool alwaysUse24HourFormat;
 
-  /// [pickTime] is a [bool] that determines if the user is able to pick a time after picking a date usring the [TimePickerDialog].
+  /// [pickTime] is a [bool] that determines if the user is able to pick a time after picking a date using the [TimePickerDialog].
   final bool pickTime;
 
   /// indicates the starting date. Default is [DateTime.now()]
   final DateTime? initialDate;
 
-  /// [markedDates] contain the dates [DateTime] that will be marked in the [DateTimePicker] by a small dot.
+  /// [markedDates] contain the dates [DateTime] that will be marked in the [DragDownDateTimePicker] by a small dot.
   final List<DateTime>? markedDates;
 
   /// a [List] of [DateTime] objects that will be disabled and cannot be interacted with whatsoever.
@@ -168,10 +168,10 @@ class DateTimePicker extends StatefulWidget {
   final List<TimeOfDay>? disabledTimes;
 
   @override
-  State<StatefulWidget> createState() => _DateTimePickerState();
+  State<StatefulWidget> createState() => _DragDownDateTimePickerState();
 }
 
-class _DateTimePickerState extends State<DateTimePicker> {
+class _DragDownDateTimePickerState extends State<DragDownDateTimePicker> {
   late DateTimePickerController _dateTimePickerController;
 
   final DraggableScrollableController _dragController =
@@ -251,7 +251,9 @@ class _DateTimePickerState extends State<DateTimePicker> {
                               ),
                             ],
                           ),
-                          child: dragSize < _dateTimePickerController.theme.weekMonthTriggerSize
+                          child: dragSize <
+                                  _dateTimePickerController
+                                      .theme.weekMonthTriggerSize
                               ? WeekDateTimePickerSheet(
                                   dateTimePickerController:
                                       _dateTimePickerController,

lib/src/models/date_time_picker_theme.dart

@@ -6,7 +6,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_date_time_picker/flutter_date_time_picker.dart';
 
 class DateTimePickerTheme {
-  /// The [DateTimePickerTheme] to style [DateTimePicker] in. Define a custom shape for the dates and specifically style
+  /// The [DateTimePickerTheme] to style [DragDownDateTimePicker] in. Define a custom shape for the dates and specifically style
   /// a basic, hightlighted, selected and disabled date.
   const DateTimePickerTheme({
     this.weekDateBoxSize = 35,

lib/src/overlay_date_time_picker.dart

@@ -0,0 +1,250 @@
+// SPDX-FileCopyrightText: 2022 Iconica
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+import 'package:flutter/material.dart';
+import 'package:flutter_date_time_picker/src/extensions/date_time.dart';
+import 'package:flutter_date_time_picker/src/models/date_time_picker_theme.dart';
+import 'package:flutter_date_time_picker/src/utils/date_time_picker_controller.dart';
+import 'package:flutter_date_time_picker/src/widgets/overlay_date_time_picker/overlay.dart';
+
+class OverlayDateTimePicker extends StatefulWidget {
+  const OverlayDateTimePicker({
+    this.theme = const DateTimePickerTheme(),
+    this.alignment = Alignment.bottomRight,
+    this.initialDate,
+    this.size = const Size(325, 325),
+    this.wrongTimeDialog,
+    this.onTapDay,
+    this.highlightToday = true,
+    this.alwaysUse24HourFormat = true,
+    this.pickTime = false,
+    this.markedDates,
+    this.disabledDates,
+    this.disabledTimes,
+    this.child,
+    super.key,
+    this.buttonBuilder,
+    this.closeOnSelectDate = true,
+  }) : assert(child != null || buttonBuilder != null);
+
+  /// The child contained by the DatePicker.
+  final Widget? child;
+
+  /// A [Widget] to display when the user picks a disabled time in the [TimePickerDialog]
+  final Widget? wrongTimeDialog;
+
+  /// Visual properties for the [OverlayDateTimePicker]
+  final DateTimePickerTheme theme;
+
+  /// Callback that provides the date tapped on as a [DateTime] object.
+  final Function(DateTime date)? onTapDay;
+
+  /// Whether the current day should be highlighted in the [OverlayDateTimePicker]
+  final bool highlightToday;
+
+  /// a [bool] to set de clock on [TimePickerDialog] to a fixed 24 or 12-hour format.
+  final bool alwaysUse24HourFormat;
+
+  /// [pickTime] is a [bool] that determines if the user is able to pick a time after picking a date using the [TimePickerDialog].
+  final bool pickTime;
+
+  /// indicates the starting date. Default is [DateTime.now()]
+  final DateTime? initialDate;
+
+  /// [markedDates] contain the dates [DateTime] that will be marked in the [OverlayDateTimePicker] by a small dot.
+  final List<DateTime>? markedDates;
+
+  /// a [List] of [DateTime] objects that will be disabled and cannot be interacted with whatsoever.
+  final List<DateTime>? disabledDates;
+
+  /// a [List] of [TimeOfDay] objects that cannot be picked in the [TimePickerDialog].
+  final List<TimeOfDay>? disabledTimes;
+
+  /// an [Alignment] to align the overlay relative to the button
+  final Alignment alignment;
+
+  /// a [Size] that indicates the size of the overlay
+  final Size size;
+
+  /// [buttonBuilder] is a method for building the button that can trigger the overlay to appear
+  final Widget Function(Key key, void Function() onPressed)? buttonBuilder;
+
+  /// [closeOnSelectDate] is a bool that indicates if the overlay should be closed if a date has been picked.
+  final bool closeOnSelectDate;
+
+  @override
+  State<OverlayDateTimePicker> createState() => _OverlayDateTimePickerState();
+}
+
+class _OverlayDateTimePickerState extends State<OverlayDateTimePicker> {
+  final GlobalKey buttonKey = GlobalKey(
+    debugLabel: "Overlay Date Time Picker - Button",
+  );
+
+  bool _isShown = false;
+
+  late OverlayState? _overlayState;
+
+  late final OverlayEntry _overlay = OverlayEntry(
+    builder: (context) {
+      var box = buttonKey.currentContext?.findRenderObject() as RenderBox;
+      var offset = _calculateOffset(
+        alignment: widget.alignment,
+        position: box.localToGlobal(
+          const Offset(0, 0),
+        ),
+        buttonSize: box.size,
+        overlaySize: widget.size,
+      );
+      return Positioned(
+        top: offset.dy,
+        left: offset.dx,
+        child: Material(
+          child: _buildOverlay(context),
+        ),
+      );
+    },
+  );
+  late final DateTimePickerController _dateTimePickerController =
+      DateTimePickerController(
+    highlightToday: widget.highlightToday,
+    alwaysUse24HourFormat: widget.alwaysUse24HourFormat,
+    pickTime: widget.pickTime,
+    theme: widget.theme,
+    markedDates: widget.markedDates,
+    disabledDates: widget.disabledDates,
+    disabledTimes: widget.disabledTimes,
+    onTapDayCallBack: (date) {
+      widget.onTapDay?.call(date);
+      if (widget.closeOnSelectDate) {
+        _toggleOverlay();
+      }
+    },
+    browsingDate: widget.initialDate ?? DateTime.now(),
+    selectedDate: widget.initialDate ?? DateTime.now(),
+  );
+
+  @override
+  void dispose() {
+    _overlay.dispose();
+    _overlayState?.dispose();
+    _dateTimePickerController.dispose();
+    super.dispose();
+  }
+
+  void _toggleOverlay() {
+    if (mounted) {
+      setState(() {
+        if (!_isShown) {
+          _overlayState?.insert(_overlay);
+        } else {
+          _overlay.remove();
+        }
+        _isShown = !_isShown;
+      });
+    }
+  }
+
+  Offset _calculateOffset({
+    required Alignment alignment,
+    required Offset position,
+    required Size buttonSize,
+    required Size overlaySize,
+  }) {
+    double offsetX = 0;
+    double offsetY = 0;
+
+    offsetX = position.dx + // adds the world x position of the button
+        buttonSize.width *
+            0.5 - // centers the pivot of the button of the calculation to the center of the button
+        overlaySize.width *
+            0.5 + // centers the pivot of the overlay of the calculation to the center of the overlay
+        (overlaySize.width + buttonSize.width) * 0.5 * alignment.x;
+    offsetY = position.dy + // adds the world y position of the button
+        buttonSize.height * 0.5 -
+        overlaySize.height * 0.5 +
+        (overlaySize.height + buttonSize.height) * 0.5 * alignment.y;
+
+    return Offset(offsetX, offsetY);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    _overlayState = Overlay.of(context);
+
+    if (widget.buttonBuilder != null) {
+      return widget.buttonBuilder!.call(
+        buttonKey,
+        () {
+          _toggleOverlay();
+        },
+      );
+    }
+    return ElevatedButton(
+        key: buttonKey,
+        onPressed: () {
+          _toggleOverlay();
+        },
+        child: widget.child);
+  }
+
+  Widget _buildOverlay(BuildContext context) {
+    return Container(
+      decoration: BoxDecoration(
+        color: widget.theme.backgroundColor,
+        borderRadius: const BorderRadius.all(Radius.circular(16)),
+        boxShadow: [
+          BoxShadow(
+            blurRadius: 5,
+            color: Colors.black.withOpacity(0.25),
+          ),
+        ],
+      ),
+      child: SizedBox(
+        width: widget.size.width,
+        height: widget.size.height,
+        child: Padding(
+          padding: const EdgeInsets.all(8.0),
+          child: OverlayDateTimeContent(
+            theme: widget.theme,
+            size: widget.size,
+            controller: _dateTimePickerController,
+            onNextDate: nextDate,
+            onPreviousDate: previousDate,
+          ),
+        ),
+      ),
+    );
+  }
+
+  void nextDate() {
+    if (!mounted) return;
+    setState(() {
+      _dateTimePickerController.browsingDate =
+          _dateTimePickerController.browsingDate.add(
+        Duration(
+          days: DateTime(
+            _dateTimePickerController.browsingDate.year,
+            _dateTimePickerController.browsingDate.month,
+          ).daysInMonth(),
+        ),
+      );
+    });
+  }
+
+  void previousDate() {
+    if (!mounted) return;
+    setState(() {
+      _dateTimePickerController.browsingDate =
+          _dateTimePickerController.browsingDate.subtract(
+        Duration(
+          days: DateTime(
+            _dateTimePickerController.browsingDate.year,
+            _dateTimePickerController.browsingDate.month,
+          ).daysInMonth(),
+        ),
+      );
+    });
+  }
+}

lib/src/widgets/overlay_date_time_picker/date_picker.dart

@@ -0,0 +1,86 @@
+// SPDX-FileCopyrightText: 2022 Iconica
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+import 'package:flutter/material.dart';
+import 'package:flutter_date_time_picker/flutter_date_time_picker.dart';
+import 'package:flutter_date_time_picker/src/extensions/date_time.dart';
+import 'package:flutter_date_time_picker/src/utils/date_time_picker_controller.dart';
+import 'package:flutter_date_time_picker/src/widgets/overlay_date_time_picker/pickable_date.dart';
+
+class DatePicker extends StatelessWidget {
+  const DatePicker({
+    super.key,
+    required this.controller,
+    required this.theme,
+    required this.onSelectDate,
+    required this.date,
+  });
+
+  final DateTimePickerController controller;
+  final DateTimePickerTheme theme;
+  final void Function(DateTime date) onSelectDate;
+  final DateTime date;
+
+  @override
+  Widget build(BuildContext context) {
+    int daysToSkip = DateTime(
+      date.year,
+      date.month,
+      0,
+      12,
+    ).weekday;
+
+    int addedIndex = 0;
+
+    if (daysToSkip >= 7) {
+      addedIndex = 7;
+    }
+
+    int length = DateTime(date.year, date.month).daysInMonth() + daysToSkip;
+    int daysToAdd = 7 - length % 7;
+    return GridView.count(
+      physics: const NeverScrollableScrollPhysics(),
+      crossAxisCount: 7,
+      children: List.generate(
+        length + daysToAdd,
+        (index) {
+          DateTime todayDate = DateTime(
+            date.year,
+            date.month,
+            addedIndex + index + 1 - daysToSkip,
+          );
+          return Padding(
+            padding: const EdgeInsets.all(2.0),
+            child: PickableDate(
+              isOffMonth: date.month != todayDate.month,
+              isDisabled: isDisabled(addedIndex + index, daysToSkip),
+              isSelected: controller.selectedDate == todayDate,
+              isToday: isToday(todayDate) && controller.highlightToday,
+              theme: theme,
+              date: todayDate,
+              onPressed: onSelectDate,
+            ),
+          );
+        },
+      ),
+    );
+  }
+
+  bool isToday(DateTime date) {
+    DateTime now = DateTime.now();
+    return date.year == now.year &&
+        date.month == now.month &&
+        date.day == now.day;
+  }
+
+  bool isDisabled(int index, int daysToSkip) {
+    return DateTime(
+      date.year,
+      date.month,
+      index + 1 - daysToSkip,
+    ).containsAny(
+      controller.disabledDates ?? [],
+    );
+  }
+}

lib/src/widgets/overlay_date_time_picker/overlay.dart

@@ -0,0 +1,174 @@
+// SPDX-FileCopyrightText: 2022 Iconica
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+import 'package:flutter/material.dart';
+import 'package:flutter_date_time_picker/src/models/date_time_picker_theme.dart';
+import 'package:flutter_date_time_picker/src/utils/date_time_picker_controller.dart';
+import 'package:flutter_date_time_picker/src/widgets/overlay_date_time_picker/date_picker.dart';
+import 'package:intl/intl.dart';
+
+class OverlayDateTimeContent extends StatefulWidget {
+  const OverlayDateTimeContent({
+    super.key,
+    required this.theme,
+    required this.size,
+    required this.controller,
+    required this.onNextDate,
+    required this.onPreviousDate,
+  });
+
+  final DateTimePickerTheme theme;
+  final Size size;
+  final DateTimePickerController controller;
+  final void Function() onNextDate;
+  final void Function() onPreviousDate;
+
+  @override
+  State<OverlayDateTimeContent> createState() => _OverlayDateTimeContentState();
+}
+
+class _OverlayDateTimeContentState extends State<OverlayDateTimeContent> {
+  bool usesButtons = false;
+  late final PageController _pageController;
+  @override
+  void initState() {
+    _pageController = PageController(initialPage: 1);
+    super.initState();
+  }
+
+  @override
+  void dispose() {
+    _pageController.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        Row(
+          mainAxisAlignment: MainAxisAlignment.spaceBetween,
+          children: [
+            IconButton(
+              onPressed: goToPreviousPage,
+              icon: const Icon(Icons.arrow_circle_left_outlined),
+              color: widget.theme.barTheme.barColor,
+            ),
+            Text(DateFormat.yMMMM().format(
+              widget.controller.browsingDate,
+            )),
+            IconButton(
+              onPressed: goToNextPage,
+              icon: const Icon(Icons.arrow_circle_right_outlined),
+              color: widget.theme.barTheme.barColor,
+            ),
+          ],
+        ),
+        Container(
+          height: 2,
+          decoration: BoxDecoration(
+            color: widget.theme.barTheme.barColor,
+          ),
+        ),
+        Expanded(
+          child: PageView(
+            controller: _pageController,
+            onPageChanged: (value) {
+              if (!usesButtons) movePage(1 - value);
+            },
+            pageSnapping: true,
+            scrollDirection: Axis.horizontal,
+            allowImplicitScrolling: true,
+            children: [
+              DatePicker(
+                controller: widget.controller,
+                onSelectDate: onSelectDate,
+                theme: widget.theme,
+                date: DateTime(
+                  widget.controller.browsingDate.year,
+                  widget.controller.browsingDate.month - 1,
+                  1,
+                ),
+              ),
+              DatePicker(
+                controller: widget.controller,
+                onSelectDate: onSelectDate,
+                theme: widget.theme,
+                date: widget.controller.browsingDate,
+              ),
+              DatePicker(
+                controller: widget.controller,
+                onSelectDate: onSelectDate,
+                theme: widget.theme,
+                date: DateTime(
+                  widget.controller.browsingDate.year,
+                  widget.controller.browsingDate.month + 1,
+                  1,
+                ),
+              ),
+            ],
+          ),
+        )
+      ],
+    );
+  }
+
+  void goToNextPage() async {
+    setState(() {
+      usesButtons = true;
+    });
+    await _pageController.nextPage(
+      duration: const Duration(milliseconds: 250),
+      curve: Curves.easeInOut,
+    );
+    nextPage();
+  }
+
+  void goToPreviousPage() async {
+    setState(() {
+      usesButtons = true;
+    });
+    await _pageController.previousPage(
+      duration: const Duration(milliseconds: 250),
+      curve: Curves.easeInOut,
+    );
+    previousPage();
+  }
+
+  void nextPage() {
+    widget.onNextDate.call();
+    if (!mounted) return;
+    setState(() {
+      usesButtons = false;
+    });
+    _pageController.jumpToPage(1);
+  }
+
+  void previousPage() {
+    widget.onPreviousDate.call();
+    if (!mounted) return;
+    setState(() {
+      usesButtons = false;
+    });
+    _pageController.jumpToPage(1);
+  }
+
+  void movePage(int direction) {
+    if (direction < 0) {
+      nextPage();
+    } else if (direction > 0) {
+      previousPage();
+    }
+  }
+
+  void onSelectDate(DateTime date) {
+    if (!mounted) return;
+    setState(() {
+      widget.controller.selectedDate = date;
+      movePage(widget.controller.browsingDate.month - date.month);
+      widget.controller.onTapDayCallBack?.call(date);
+    });
+  }
+}

lib/src/widgets/overlay_date_time_picker/pickable_date.dart

@@ -0,0 +1,82 @@
+// SPDX-FileCopyrightText: 2022 Iconica
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+import 'package:flutter/material.dart';
+import 'package:flutter_date_time_picker/flutter_date_time_picker.dart';
+
+class PickableDate extends StatelessWidget {
+  const PickableDate({
+    super.key,
+    required this.isSelected,
+    required this.isDisabled,
+    required this.theme,
+    required this.onPressed,
+    required this.date,
+    required this.isOffMonth,
+    required this.isToday,
+  });
+
+  final bool isSelected;
+  final bool isDisabled;
+  final bool isToday;
+  final bool isOffMonth;
+  final DateTime date;
+  final DateTimePickerTheme theme;
+  final void Function(DateTime date) onPressed;
+
+  @override
+  Widget build(BuildContext context) {
+    return GestureDetector(
+      behavior: HitTestBehavior.opaque,
+      onTap: () {
+        if (isDisabled) return;
+        onPressed.call(date);
+      },
+      child: Container(
+        decoration: BoxDecoration(
+          color: getColor(
+            isToday,
+            isSelected,
+          ),
+          borderRadius: getBorder(theme.dateBoxShape),
+        ),
+        child: Center(
+          child: Opacity(
+            opacity: (isDisabled || isOffMonth) ? 0.5 : 1,
+            child: Text(
+              date.day.toString(),
+              style: getStyle(
+                isToday,
+                isSelected,
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  BorderRadiusGeometry? getBorder(DateBoxShape shape) {
+    switch (shape) {
+      case DateBoxShape.circle:
+        return BorderRadius.all(Radius.circular(theme.monthDateBoxSize));
+      case DateBoxShape.roundedRectangle:
+        return const BorderRadius.all(Radius.circular(10));
+      case DateBoxShape.rectangle:
+        return null;
+    }
+  }
+
+  Color? getColor(bool isToday, bool isSelected) {
+    if (isToday) return theme.highlightTheme.backgroundColor;
+    if (isSelected) return theme.selectedTheme.backgroundColor;
+    return null;
+  }
+
+  TextStyle? getStyle(bool isToday, bool isSelected) {
+    if (isToday) return theme.highlightTheme.textStyle;
+    if (isSelected) return theme.selectedTheme.textStyle;
+    return null;
+  }
+}

test/flutter_date_time_picker_test.dart

@@ -12,7 +12,7 @@ void main() {
     await tester.pumpWidget(MaterialApp(
       home: Scaffold(
         appBar: AppBar(),
-        body: DateTimePicker(
+        body: DragDownDateTimePicker(
           pickTime: false,
           child: Container(),
         ),
@@ -26,7 +26,7 @@ void main() {
     await tester.pumpWidget(MaterialApp(
       home: Scaffold(
         appBar: AppBar(),
-        body: DateTimePicker(
+        body: DragDownDateTimePicker(
           pickTime: false,
           child: Container(),
         ),