feat: add year button implementation.

demo/Ursa.Demo/Pages/DatePickerDemo.axaml

@@ -7,30 +7,6 @@
              x:Class="Ursa.Demo.Pages.DatePickerDemo">
     <StackPanel Margin="20" HorizontalAlignment="Left">
         <u:CalendarMonthView />
-        <u:CalendarDayButton />
-        <u:CalendarDayButton IsSelected="True" />
-        <u:CalendarDayButton IsBlackout="True" />
-        <StackPanel Orientation="Horizontal">
-            <u:CalendarDayButton IsStartDate="True" />
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsEndDate="True" />
-        </StackPanel>
-        <StackPanel Orientation="Horizontal" DataValidationErrors.Errors="{Binding items}">
-            <u:CalendarDayButton IsPreviewStartDate="True" />
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsPreviewEndDate="True" />
-        </StackPanel>
-        <StackPanel Orientation="Horizontal">
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsInRange="True" IsStartDate="True" />
-            <u:CalendarDayButton IsInRange="True" />
-            <u:CalendarDayButton IsEndDate="True" IsInRange="True" />
-            <u:CalendarDayButton IsInRange="True" />
-        </StackPanel>
         <u:Calendar/>
     </StackPanel>
 </UserControl>

src/Ursa/Controls/DateTimePicker/Calendar.cs

@@ -26,7 +26,8 @@ public class Calendar: TemplatedControl
     public const string PART_MonthView = "PART_MonthView";
     public const string PART_YearView = "PART_YearView";
 
-    private CalendarMonthView? _monthGrid;
+    private CalendarMonthView? _monthView;
+    private CalendarYearView? _yearView;
     private DatePickerState _state = DatePickerState.None;
     
     
@@ -78,22 +79,23 @@ public class Calendar: TemplatedControl
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);
-        if (_monthGrid is not null)
+        if (_monthView is not null)
         {
-            _monthGrid.OnCalendarDayButtonPressed -= OnCalendarDayButtonPressed;
+            _monthView.OnDateSelected -= OnDateSelected;
-            _monthGrid.OnCalendarDayButtonPointerEnter -= OnCalendarDayButtonPointerEnter;
+            _monthView.OnDatePreviewed -= OnDatePreviewed;
         }
-        _monthGrid = e.NameScope.Find<CalendarMonthView>(PART_MonthView);
+        _monthView = e.NameScope.Find<CalendarMonthView>(PART_MonthView);
-        if(_monthGrid is not null)
+        _yearView = e.NameScope.Find<CalendarYearView>(PART_YearView);
+        if(_monthView is not null)
         {
-            _monthGrid.OnCalendarDayButtonPressed += OnCalendarDayButtonPressed;
+            _monthView.OnDateSelected += OnDateSelected;
-            _monthGrid.OnCalendarDayButtonPointerEnter += OnCalendarDayButtonPointerEnter;
+            _monthView.OnDatePreviewed += OnDatePreviewed;
         }
     }
 
-    private void OnCalendarDayButtonPointerEnter(object sender, CalendarDayButtonEventArgs e)
+    private void OnDatePreviewed(object sender, CalendarDayButtonEventArgs e)
     {
-        if(_monthGrid is null)
+        if(_monthView is null)
         {
             return;
         }
@@ -101,38 +103,38 @@ public class Calendar: TemplatedControl
         if (_state is DatePickerState.None) return;
         if (_state == DatePickerState.PreviewStart)
         {
-            _monthGrid.MarkPreview(date, EndDate);
+            _monthView.MarkPreview(date, EndDate);
         }
         else if (_state == DatePickerState.PreviewEnd)
         {
-            _monthGrid.MarkPreview(StartDate, date);
+            _monthView.MarkPreview(StartDate, date);
         }
     }
 
-    private void OnCalendarDayButtonPressed(object sender, CalendarDayButtonEventArgs e)
+    private void OnDateSelected(object sender, CalendarDayButtonEventArgs e)
     {
-        if(_monthGrid is null)
+        if(_monthView is null)
         {
             return;
         }
         var date = e.Date;
         if (_state == DatePickerState.None)
         {
-            _monthGrid.ClearSelection();
+            _monthView.ClearSelection();
-            _monthGrid.ClearPreview();
+            _monthView.ClearPreview();
-            _monthGrid.MarkSelection(date, null);
+            _monthView.MarkSelection(date, null);
             _state = DatePickerState.PreviewEnd;
             StartDate = date;
         }
         else if (_state == DatePickerState.PreviewStart)
         {
-            _monthGrid.MarkSelection(date, EndDate);
+            _monthView.MarkSelection(date, EndDate);
             _state = DatePickerState.SelectStart;
             StartDate = date;
         }
         else if (_state == DatePickerState.PreviewEnd)
         {
-            _monthGrid.MarkSelection(StartDate, date);
+            _monthView.MarkSelection(StartDate, date);
             _state = DatePickerState.None;
             EndDate = date;
         }

src/Ursa/Controls/DateTimePicker/CalendarDayButton.cs

@@ -4,8 +4,10 @@ using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
+using Avalonia.Interactivity;
 using Irihi.Avalonia.Shared.Common;
 using Irihi.Avalonia.Shared.Helpers;
+using Ursa.EventArgs;
 
 namespace Ursa.Controls;
 
@@ -128,6 +130,24 @@ public class CalendarDayButton: ContentControl
             PseudoClasses.Set(PC_NotCurrentMonth, value);
         }
     }
+    
+    public static readonly RoutedEvent<CalendarDayButtonEventArgs> DateSelectedEvent = RoutedEvent.Register<CalendarDayButton, CalendarDayButtonEventArgs>(
+        nameof(DateSelected), RoutingStrategies.Bubble);
+    
+    public event EventHandler<CalendarDayButtonEventArgs> DateSelected
+    {
+        add => AddHandler(DateSelectedEvent, value);
+        remove => RemoveHandler(DateSelectedEvent, value);
+    }
+    
+    public static readonly RoutedEvent<CalendarDayButtonEventArgs> DatePreviewedEvent = RoutedEvent.Register<CalendarDayButton, CalendarDayButtonEventArgs>(
+        nameof(DatePreviewed), RoutingStrategies.Bubble);
+    
+    public event EventHandler<CalendarDayButtonEventArgs> DatePreviewed
+    {
+        add => AddHandler(DateSelectedEvent, value);
+        remove => RemoveHandler(DateSelectedEvent, value); 
+    }
 
     static CalendarDayButton()
     {
@@ -145,4 +165,22 @@ public class CalendarDayButton: ContentControl
         PseudoClasses.Set(PC_InRange, IsInRange);
         PseudoClasses.Set(PseudoClassName.PC_Selected, IsSelected);
     }
+    
+    protected override void OnPointerPressed(PointerPressedEventArgs e)
+    {
+        base.OnPointerPressed(e);
+        if (this.DataContext is DateTime d)
+        {
+            RaiseEvent(new CalendarDayButtonEventArgs(d) { RoutedEvent = DateSelectedEvent, Source = this });
+        }
+    }
+
+    protected override void OnPointerEntered(PointerEventArgs e)
+    {
+        base.OnPointerEntered(e);
+        if (this.DataContext is DateTime d)
+        {
+            RaiseEvent(new CalendarDayButtonEventArgs(d) { RoutedEvent = DateSelectedEvent, Source = this });
+        }
+    }
 }

src/Ursa/Controls/DateTimePicker/CalendarMonthView.cs

@@ -88,14 +88,26 @@ public class CalendarMonthView : TemplatedControl
             var cell = new CalendarDayButton();
             cell.SetValue(Grid.RowProperty, i);
             cell.SetValue(Grid.ColumnProperty, j);
-            cell.PointerPressed += OnDayButtonPressed;
+            cell.AddHandler(CalendarDayButton.DateSelectedEvent, OnCellDateSelected);
-            cell.PointerEntered += OnDayButtonPointerEnter;
+            cell.AddHandler(CalendarDayButton.DatePreviewedEvent, OnCellDatePreviewed);
             children.Add(cell);
         }
 
         _grid?.Children.AddRange(children);
     }
 
+    private void OnCellDatePreviewed(object sender, CalendarDayButtonEventArgs e)
+    {
+        OnDatePreviewed?.Invoke(sender, e);
+    }
+
+    private void OnCellDateSelected(object sender, CalendarDayButtonEventArgs e)
+    {
+        OnDateSelected?.Invoke(sender, e);
+    }
+    
+    
+
     private void SetDayButtons(DateTime date)
     {
         if (_grid is null) return;
@@ -117,18 +129,6 @@ public class CalendarMonthView : TemplatedControl
         FadeOutDayButtons();
     }
 
-    private void OnDayButtonPressed(object sender, PointerPressedEventArgs e)
-    {
-        if (sender is CalendarDayButton { DataContext: DateTime d })
-            OnCalendarDayButtonPressed?.Invoke(this, new CalendarDayButtonEventArgs(d));
-    }
-
-    private void OnDayButtonPointerEnter(object sender, PointerEventArgs e)
-    {
-        if (sender is CalendarDayButton { DataContext: DateTime d })
-            OnCalendarDayButtonPointerEnter?.Invoke(this, new CalendarDayButtonEventArgs(d));
-    }
-
     private int PreviousMonthDays(DateTime date)
     {
         var firstDay = date.GetFirstDayOfMonth();
@@ -151,8 +151,8 @@ public class CalendarMonthView : TemplatedControl
     }
 
 
-    public event EventHandler<CalendarDayButtonEventArgs>? OnCalendarDayButtonPressed;
+    public event EventHandler<CalendarDayButtonEventArgs>? OnDateSelected;
-    public event EventHandler<CalendarDayButtonEventArgs>? OnCalendarDayButtonPointerEnter;
+    public event EventHandler<CalendarDayButtonEventArgs>? OnDatePreviewed;
 
     public void MarkSelection(DateTime? start, DateTime? end)
     {
@@ -164,12 +164,14 @@ public class CalendarMonthView : TemplatedControl
                 if (d == start)
                 {
                     button.IsStartDate = true;
+                    button.IsPreviewStartDate = false;
                     button.IsEndDate = false;
                     button.IsInRange = false;
                 }
                 else if (d == end)
                 {
                     button.IsEndDate = true;
+                    button.IsPreviewEndDate = false;
                     button.IsStartDate = false;
                     button.IsInRange = false;
                 }

src/Ursa/Controls/DateTimePicker/CalendarYearButton.cs

@@ -0,0 +1,46 @@
+using System.Diagnostics;
+using Avalonia.Controls;
+using Avalonia.Controls.Mixins;
+namespace Ursa.Controls;
+
+internal enum CalendarYearViewMode
+{
+    Month,
+    Year,
+    // The button represents ten year, with one year before and one year after, 12 in total. 
+    YearRange,
+} 
+public class CalendarYearButton: ContentControl
+{
+    static CalendarYearButton()
+    {
+        PressedMixin.Attach<CalendarYearButton>();
+    }
+    
+    internal int Year { get; private set; }
+    
+    internal int Month { get; private set; }
+    
+    internal int StartYear { get; private set; }
+    
+    internal int EndYear { get; private set; }
+    
+    internal CalendarYearViewMode Mode { get; private set; }
+
+    internal void SetValues(CalendarYearViewMode mode, DateTime contextDate, int? month = null, int? year = null, int? startYear = null, int? endYear = null)
+    {
+        Debug.Assert(!(month is null && year is null && startYear is null && endYear is null));
+        Mode = mode;
+        Month = month ?? 0;
+        Year = year ?? 0;
+        StartYear = startYear ?? 0;
+        EndYear = endYear ?? 0;
+        Content = Mode switch
+        {
+            CalendarYearViewMode.Month => DateTimeHelper.GetCurrentDateTimeFormatInfo().AbbreviatedMonthNames[Month],
+            CalendarYearViewMode.Year => Year.ToString(),
+            CalendarYearViewMode.YearRange => StartYear + "-" + EndYear,
+            _ => Content
+        };
+    }
+}

src/Ursa/Controls/DateTimePicker/CalendarYearButtonEventArgs.cs

@@ -0,0 +1,8 @@
+using Avalonia.Interactivity;
+
+namespace Ursa.Controls;
+
+public class CalendarYearButtonEventArgs: RoutedEventArgs
+{
+    
+}

src/Ursa/Controls/DateTimePicker/CalendarYearView.cs

@@ -1,3 +1,8 @@
+using Avalonia.Controls;
+using Avalonia.Controls.Documents;
+using Avalonia.Controls.Metadata;
+using Avalonia.Controls.Primitives;
+
 namespace Ursa.Controls;
 
 /// <summary>
@@ -6,7 +11,82 @@ namespace Ursa.Controls;
 /// 2. show 12 years, one year per button (but only 10 buttons clickable)
 /// 3. show 120 years, ten year per button (but only 10 buttons clickable)
 /// </summary>
-public class CalendarYearView
+[TemplatePart(PART_Grid, typeof(Grid))]
+public class CalendarYearView: TemplatedControl
 {
+    public const string PART_Grid = "PART_Grid";
+    
+    private CalendarYearViewMode _mode = CalendarYearViewMode.Month;
+
+    internal CalendarYearViewMode Mode
+    {
+        get => _mode;
+        set
+        {
+            _mode = value;
+            RefreshButtons();
+        }
+    }
+
+    private DateTime _contextDate = DateTime.Today;
+    internal DateTime ContextDate
+    {
+        get => _contextDate;
+        set
+        {
+            _contextDate = value;
+            RefreshButtons();
+        }
+    }
+
+    private Grid? _grid;
+    protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+    {
+        base.OnApplyTemplate(e);
+        _grid = e.NameScope.Find<Grid>(PART_Grid);
+        GenerateGridElements();
+    }
+    
+    public void GenerateGridElements()
+    {
+        if (_grid is null)
+        {
+            return;
+        }
+        _grid.Children.Clear();
+        for (var i = 0; i < 12; i++)
+        {
+            var button = new CalendarYearButton();
+            Grid.SetRow(button, i / 3);
+            Grid.SetColumn(button, i % 3);
+            _grid.Children.Add(button);
+        }
+    }
+
+    private void RefreshButtons()
+    {
+        if (_grid is null) return;
+        var mode = Mode;
+        var contextDate = ContextDate;
+        for (var i = 0; i < 12; i++)
+        {
+            var child = _grid.Children[i] as CalendarYearButton;
+            if (child is null) continue;
+            switch (mode)
+            {
+                case CalendarYearViewMode.Month:
+                    child.SetValues(CalendarYearViewMode.Month, contextDate, month: i);
+                    break;
+                case CalendarYearViewMode.Year:
+                    child.SetValues(CalendarYearViewMode.Year, contextDate, year: ContextDate.Year + i);
+                    break;
+                case CalendarYearViewMode.YearRange:
+                    var startYear = ContextDate.Year - 1;
+                    var endYear = ContextDate.Year + 10;
+                    child.SetValues(CalendarYearViewMode.YearRange, contextDate, startYear: startYear, endYear: endYear);
+                    break;
+            }
+        }
+    }
     
 }