feat: wip.

src/Ursa/Controls/DateTimePicker/CalendarDisplayControl.cs

@@ -31,54 +31,31 @@ public class CalendarDisplayControl: TemplatedControl
 
     private CalendarMonthView? _monthView;
     private CalendarYearView? _yearView;
+    // Year button only shows the year in month mode.
     private Button? _yearButton;
+    // Month button only shows the month in month mode.
     private Button? _monthButton;
+    // Header button shows year in year mode, and year range in higher mode. 
     private Button? _headerButton;
     
     public event EventHandler<CalendarDayButtonEventArgs>? OnDateSelected;
     public event EventHandler<CalendarDayButtonEventArgs>? OnDatePreviewed;
-    
-    
-    public static readonly StyledProperty<DateTime> SelectedDateProperty = AvaloniaProperty.Register<CalendarDisplayControl, DateTime>(nameof(SelectedDate), DateTime.Now);
-    public DateTime SelectedDate
-    {
-        get => GetValue(SelectedDateProperty);
-        set => SetValue(SelectedDateProperty, value);
-    }
 
-    public static readonly StyledProperty<DayOfWeek> FirstDayOfWeekProperty =
+    public static readonly StyledProperty<bool> IsTodayHighlightedProperty =
-        AvaloniaProperty.Register<CalendarDisplayControl, DayOfWeek>(nameof(FirstDayOfWeek),
+        DatePickerBase.IsTodayHighlightedProperty.AddOwner<CalendarDisplayControl>();
-            defaultValue: DateTimeHelper.GetCurrentDateTimeFormatInfo().FirstDayOfWeek);
-    public DayOfWeek FirstDayOfWeek
-    {
-        get => GetValue(FirstDayOfWeekProperty);
-        set => SetValue(FirstDayOfWeekProperty, value);
-    }
-
-    public static readonly StyledProperty<bool> IsTodayHighlightedProperty = AvaloniaProperty.Register<CalendarDisplayControl, bool>(nameof(IsTodayHighlighted), true);
     public bool IsTodayHighlighted
     {
         get => GetValue(IsTodayHighlightedProperty);
         set => SetValue(IsTodayHighlightedProperty, value);
     }
 
-    public static readonly StyledProperty<AvaloniaList<DateRange>?> BlackoutDatesProperty =
+    public static readonly StyledProperty<DayOfWeek> FirstDayOfWeekProperty =
-        AvaloniaProperty.Register<CalendarDisplayControl, AvaloniaList<DateRange>?>(
+        DatePickerBase.FirstDayOfWeekProperty.AddOwner<CalendarDisplayControl>();
-            nameof(BlackoutDates));
+    
-
+    public DayOfWeek FirstDayOfWeek
-    public AvaloniaList<DateRange>? BlackoutDates
     {
-        get => GetValue(BlackoutDatesProperty);
+        get => GetValue(FirstDayOfWeekProperty);
-        set => SetValue(BlackoutDatesProperty, value);
+        set => SetValue(FirstDayOfWeekProperty, value);
-    }
-
-    public static readonly StyledProperty<IDateSelector?> BlackoutDateRuleProperty = AvaloniaProperty.Register<CalendarDisplayControl, IDateSelector?>(
-        nameof(BlackoutDateRule));
-
-    public IDateSelector? BlackoutDateRule
-    {
-        get => GetValue(BlackoutDateRuleProperty);
-        set => SetValue(BlackoutDateRuleProperty, value);
     }
 
     private bool _isMonthMode = true;
@@ -92,16 +69,13 @@ public class CalendarDisplayControl: TemplatedControl
         set => SetAndRaise(IsMonthModeProperty, ref _isMonthMode, value);
     }
 
-    internal DateTime? StartDate;
-    internal DateTime? EndDate;
-
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);
         if (_monthView is not null)
         {
-            _monthView.OnDateSelected -= OnDateSelected;
+            _monthView.OnDateSelected -= OnMonthViewDateSelected;
-            _monthView.OnDatePreviewed -= OnDatePreviewed;
+            _monthView.OnDatePreviewed -= OnMonthViewDatePreviewed;
         }
 
         if (_yearView is not null)
@@ -118,8 +92,8 @@ public class CalendarDisplayControl: TemplatedControl
         _headerButton = e.NameScope.Find<Button>(PART_HeaderButton);
         if(_monthView is not null)
         {
-            _monthView.OnDateSelected += OnDateSelected;
+            _monthView.OnDateSelected += OnMonthViewDateSelected;
-            _monthView.OnDatePreviewed += OnDatePreviewed;
+            _monthView.OnDatePreviewed += OnMonthViewDatePreviewed;
         }
 
         if (_yearView is not null)
@@ -131,6 +105,11 @@ public class CalendarDisplayControl: TemplatedControl
         Button.ClickEvent.AddHandler(OnHeaderButtonClick, _headerButton);
     }
 
+    /// <summary>
+    /// Rule: 
+    /// </summary>
+    /// <param name="sender"></param>
+    /// <param name="e"></param>
     private void OnHeaderButtonClick(object sender, RoutedEventArgs e)
     {
         if (_yearView?.Mode == CalendarYearViewMode.Month)

src/Ursa/Controls/DateTimePicker/CalendarMonthView.cs

@@ -16,10 +16,10 @@ namespace Ursa.Controls;
 public class CalendarMonthView : TemplatedControl
 {
     public const string PART_Grid = "PART_Grid";
+    private const string ShortestDayName = "ShortestDayName";
 
     public static readonly StyledProperty<DayOfWeek> FirstDayOfWeekProperty =
-        AvaloniaProperty.Register<CalendarMonthView, DayOfWeek>(
+        DatePickerBase.FirstDayOfWeekProperty.AddOwner<CalendarMonthView>();
-            nameof(FirstDayOfWeek));
 
     private readonly System.Globalization.Calendar _calendar = new GregorianCalendar();
 
@@ -56,12 +56,14 @@ public class CalendarMonthView : TemplatedControl
         base.OnApplyTemplate(e);
         _grid = e.NameScope.Find<Grid>(PART_Grid);
         GenerateGridElements();
-        SetDayButtons(DateTime.Today);
+        SetDayButtons(ContextDate);
     }
 
     private void OnDayOfWeekChanged(AvaloniaPropertyChangedEventArgs<DayOfWeek> args)
     {
         // throw new NotImplementedException();
+        UpdateGridElements();
+        SetDayButtons(ContextDate);
     }
 
 
@@ -75,7 +77,7 @@ public class CalendarMonthView : TemplatedControl
         for (var i = 0; i < 7; i++)
         {
             var d = (dayOfWeek + i) % DateTimeHelper.NumberOfDaysPerWeek;
-            var cell = new TextBlock { Text = info.ShortestDayNames[d] };
+            var cell = new TextBlock { Text = info.ShortestDayNames[d], Tag = ShortestDayName };
             cell.SetValue(HorizontalAlignmentProperty, HorizontalAlignment.Center);
             cell.SetValue(Grid.RowProperty, 0);
             cell.SetValue(Grid.ColumnProperty, i);
@@ -97,6 +99,27 @@ public class CalendarMonthView : TemplatedControl
         _grid?.Children.AddRange(children);
     }
 
+    private void UpdateGridElements()
+    {
+        var count = 7 + 7 * 7;
+        // var children = new List<Control>(count);
+        var dayOfWeek = (int)FirstDayOfWeek;
+        var info = DateTimeHelper.GetCurrentDateTimeFormatInfo();
+        var textblocks = _grid?.Children.Where(a => a is TextBlock { Tag: ShortestDayName }).ToList();
+        if (textblocks is not null)
+        {
+            for (var i = 0; i < 7; i++)
+            {
+                var d = (dayOfWeek + i) % DateTimeHelper.NumberOfDaysPerWeek;
+                textblocks[i].SetValue(TextBlock.TextProperty, info.ShortestDayNames[d]);
+                textblocks[i].SetValue(HorizontalAlignmentProperty, HorizontalAlignment.Center);
+                textblocks[i].SetValue(Grid.RowProperty, 0);
+                textblocks[i].SetValue(Grid.ColumnProperty, i);
+            }
+        }
+        SetDayButtons(ContextDate);
+    }
+
     private void OnCellDatePreviewed(object sender, CalendarDayButtonEventArgs e)
     {
         OnDatePreviewed?.Invoke(sender, e);
@@ -179,40 +202,7 @@ public class CalendarMonthView : TemplatedControl
             if (d == startDate && d == endDate) button.IsSelected = true;
         }
     }
-
+    
-    public void MarkPreview(DateTime? start, DateTime? end)
-    {
-        if (_grid?.Children is null) return;
-        foreach (var child in _grid.Children)
-        {
-            if (child is not CalendarDayButton { DataContext: DateTime d } button) continue;
-            if (d == start)
-            {
-                button.IsPreviewStartDate = true;
-                button.IsPreviewEndDate = false;
-                button.IsInRange = false;
-            }
-            else if (d == end)
-            {
-                button.IsPreviewEndDate = true;
-                button.IsPreviewStartDate = false;
-                button.IsInRange = false;
-            }
-            else if (d > start && d < end)
-            {
-                button.IsInRange = true;
-                button.IsPreviewStartDate = false;
-                button.IsPreviewEndDate = false;
-            }
-            else
-            {
-                button.IsPreviewStartDate = false;
-                button.IsPreviewEndDate = false;
-                button.IsInRange = false;
-            }
-        }
-    }
-
     public void ClearSelection()
     {
         if (_grid?.Children is null) return;

src/Ursa/Controls/DateTimePicker/CalendarYearView.cs

@@ -100,11 +100,11 @@ public class CalendarYearView: TemplatedControl
                     child.SetValues(CalendarYearViewMode.Month, contextDate, month: i);
                     break;
                 case CalendarYearViewMode.Year:
-                    child.SetValues(CalendarYearViewMode.Year, contextDate, year: ContextDate.Year + i);
+                    child.SetValues(CalendarYearViewMode.Year, contextDate, year: ContextDate.Year / 10 * 10 + i - 1);
                     break;
                 case CalendarYearViewMode.YearRange:
-                    var startYear = ContextDate.Year - 1;
+                    var startYear = (ContextDate.Year / 10 + i - 1) * 10;
-                    var endYear = ContextDate.Year + 10;
+                    var endYear = (ContextDate.Year / 10 + i - 1) * 10 + 10;
                     child.SetValues(CalendarYearViewMode.YearRange, contextDate, startYear: startYear, endYear: endYear);
                     break;
             }

src/Ursa/Controls/DateTimePicker/DatePicker.cs

@@ -2,7 +2,7 @@
 
 namespace Ursa.Controls;
 
-public class DatePicker: TemplatedControl
+public class DatePicker: DatePickerBase
 {
     
 }

src/Ursa/Controls/DateTimePicker/DatePickerBase.cs

@@ -0,0 +1,46 @@
+using Avalonia;
+using Avalonia.Collections;
+using Avalonia.Controls.Primitives;
+using Avalonia.Controls.Templates;
+
+namespace Ursa.Controls;
+
+public class DatePickerBase: TemplatedControl
+{
+    public static readonly StyledProperty<AvaloniaList<DateRange>> BlackoutDatesProperty =
+        AvaloniaProperty.Register<DatePickerBase, AvaloniaList<DateRange>>(nameof(BlackoutDates));
+
+    public AvaloniaList<DateRange> BlackoutDates
+    {
+        get => GetValue(BlackoutDatesProperty);
+        set => SetValue(BlackoutDatesProperty, value);
+    }
+
+    public static readonly StyledProperty<IDateSelector?> BlackoutDateRuleProperty =
+        AvaloniaProperty.Register<DatePickerBase, IDateSelector?>(nameof(BlackoutDateRule));
+
+    public IDateSelector? BlackoutDateRule
+    {
+        get => GetValue(BlackoutDateRuleProperty);
+        set => SetValue(BlackoutDateRuleProperty, value);
+    }
+
+    public static readonly StyledProperty<DayOfWeek> FirstDayOfWeekProperty =
+        AvaloniaProperty.Register<DatePickerBase, DayOfWeek>(
+            nameof(FirstDayOfWeek), DateTimeHelper.GetCurrentDateTimeFormatInfo().FirstDayOfWeek);
+
+    public DayOfWeek FirstDayOfWeek
+    {
+        get => GetValue(FirstDayOfWeekProperty);
+        set => SetValue(FirstDayOfWeekProperty, value);
+    }
+    
+    public static readonly StyledProperty<bool> IsTodayHighlightedProperty =
+        AvaloniaProperty.Register<DatePickerBase, bool>(nameof(IsTodayHighlighted), true);
+    public bool IsTodayHighlighted
+    {
+        get => GetValue(IsTodayHighlightedProperty);
+        set => SetValue(IsTodayHighlightedProperty, value);
+    }
+    
+}

src/Ursa/Controls/DateTimePicker/IDateSelector.cs

@@ -2,14 +2,14 @@
 
 public interface IDateSelector
 {
-    public bool IsValid(DateTime? date); 
+    public bool Match(DateTime? date); 
 }
 
 public class WeekendDateSelector: IDateSelector
 {
     public static WeekendDateSelector Instance { get; } = new WeekendDateSelector();
     
-    public bool IsValid(DateTime? date)
+    public bool Match(DateTime? date)
     {
         if (date is null) return false;
         return date.Value.DayOfWeek == DayOfWeek.Saturday || date.Value.DayOfWeek == DayOfWeek.Sunday;