feat: wip: implement year view notification.

demo/Ursa.Demo/Pages/DatePickerDemo.axaml

@@ -7,6 +7,7 @@
              x:Class="Ursa.Demo.Pages.DatePickerDemo">
     <StackPanel Margin="20" HorizontalAlignment="Left">
         <u:CalendarMonthView />
+        <u:CalendarYearView />
         <u:Calendar/>
     </StackPanel>
 </UserControl>

src/Ursa.Themes.Semi/Controls/Calendar.axaml

@@ -4,7 +4,7 @@
     xmlns:u="https://irihi.tech/ursa">
     <Design.PreviewWith>
         <StackPanel Margin="20" Spacing="5">
-            <u:CalendarMonthView/>
+            <u:CalendarMonthView />
             <u:Calendar />
         </StackPanel>
     </Design.PreviewWith>
@@ -121,6 +121,7 @@
     </ControlTheme>
 
     <ControlTheme x:Key="{x:Type u:Calendar}" TargetType="u:Calendar">
+        <Setter Property="MinHeight" Value="300"></Setter>
         <Setter Property="Template">
             <ControlTemplate TargetType="u:Calendar">
                 <Panel>
@@ -152,13 +153,20 @@
                                     Foreground="{DynamicResource CalendarItemIconForeground}" />
                             </Button>
 
-                            <Button
+                            <Grid ColumnDefinitions="*, *" Grid.Column="2">
-                                Name="PART_HeaderButton"
+                                <Button Grid.Column="0"
-                                Grid.Column="2"
+                                    Name="{x:Static u:Calendar.PART_YearButton}"
-                                HorizontalContentAlignment="Center"
+                                    HorizontalContentAlignment="Center"
-                                Content="Apr 2024"
+                                    Content="2024"
-                                Foreground="{TemplateBinding Foreground}"
+                                    Foreground="{TemplateBinding Foreground}"
-                                Theme="{DynamicResource BorderlessButton}" />
+                                    Theme="{DynamicResource BorderlessButton}" />
+                                <Button Grid.Column="1"
+                                    Name="{x:Static u:Calendar.PART_MonthButton}"
+                                    HorizontalContentAlignment="Center"
+                                    Content="Apr"
+                                    Foreground="{TemplateBinding Foreground}"
+                                    Theme="{DynamicResource BorderlessButton}" />
+                            </Grid>
 
                             <Button
                                 Name="{x:Static u:Calendar.PART_NextButton}"
@@ -185,7 +193,18 @@
                                     Foreground="{DynamicResource CalendarItemIconForeground}" />
                             </Button>
                         </Grid>
-                        <u:CalendarMonthView Grid.Row="1" Name="{x:Static u:Calendar.PART_MonthView}"></u:CalendarMonthView>
+                        <u:CalendarMonthView
+                            Name="{x:Static u:Calendar.PART_MonthView}"
+                            Grid.Row="1"
+                            VerticalAlignment="Top"
+                            IsVisible="{TemplateBinding IsMonthMode}" />
+                        <u:CalendarYearView
+                            Name="{x:Static u:Calendar.PART_YearView}"
+                            Grid.Row="1"
+                            HorizontalAlignment="Stretch"
+                            VerticalAlignment="Stretch"
+                            IsVisible="{TemplateBinding IsMonthMode,
+                                                        Converter={x:Static BoolConverters.Not}}" />
                     </Grid>
 
                 </Panel>
@@ -193,20 +212,76 @@
         </Setter>
     </ControlTheme>
 
-    <ControlTheme TargetType="u:CalendarMonthView" x:Key="{x:Type u:CalendarMonthView}">
+    <ControlTheme x:Key="{x:Type u:CalendarMonthView}" TargetType="u:CalendarMonthView">
         <Setter Property="Template">
             <ControlTemplate>
-                <Grid Name="{x:Static u:CalendarMonthView.PART_Grid}" ColumnDefinitions="*, *, *, *, *, *, *" RowDefinitions="*, Auto, *, *, *, *, *, *">
+                <Grid
+                    Name="{x:Static u:CalendarMonthView.PART_Grid}"
+                    ColumnDefinitions="*, *, *, *, *, *, *"
+                    RowDefinitions="*, Auto, *, *, *, *, *, *">
                     <Rectangle
-                        Grid.Column="0"
                         Grid.Row="1"
+                        Grid.Column="0"
                         Grid.ColumnSpan="7"
                         Height="1"
-                        Margin="8 8 8 0"
+                        Margin="8,8,8,0"
                         HorizontalAlignment="Stretch"
                         Fill="{DynamicResource SemiGrey2}" />
                 </Grid>
             </ControlTemplate>
         </Setter>
     </ControlTheme>
+
+    <ControlTheme x:Key="{x:Type u:CalendarYearView}" TargetType="u:CalendarYearView">
+        <Setter Property="Template">
+            <ControlTemplate>
+                <Grid
+                    Name="{x:Static u:CalendarYearView.PART_Grid}"
+                    ColumnDefinitions="*, *, *"
+                    RowDefinitions="*, *, *, *" />
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
+
+    <ControlTheme x:Key="{x:Type u:CalendarYearButton}" TargetType="u:CalendarYearButton">
+        <Setter Property="MinWidth" Value="32" />
+        <Setter Property="MinHeight" Value="32" />
+        <Setter Property="Margin" Value="0 2" />
+        <Setter Property="Background" Value="Transparent" />
+        <Setter Property="BorderBrush" Value="Transparent" />
+        <Setter Property="BorderThickness" Value="1" />
+        <Setter Property="CornerRadius" Value="3" />
+        <Setter Property="Template">
+            <ControlTemplate TargetType="u:CalendarDayButton">
+                <Panel>
+                    <Border
+                        Name="PART_Background"
+                        Background="{TemplateBinding Background}"
+                        BorderBrush="{TemplateBinding BorderBrush}"
+                        BorderThickness="{TemplateBinding BorderThickness}"
+                        CornerRadius="{TemplateBinding CornerRadius}">
+                        <ContentPresenter
+                            Name="PART_ContentPresenter"
+                            HorizontalAlignment="Center"
+                            VerticalAlignment="Center"
+                            Content="{TemplateBinding Content}"
+                            Foreground="{TemplateBinding Foreground}" />
+                    </Border>
+                </Panel>
+            </ControlTemplate>
+        </Setter>
+        <Style Selector="^:pointerover">
+            <Setter Property="Background" Value="{DynamicResource SemiGrey1}" />
+            <Setter Property="Cursor" Value="Hand" />
+        </Style>
+        <Style Selector="^:selected">
+            <Setter Property="Background" Value="{DynamicResource SemiBlue5}" />
+            <Setter Property="CornerRadius" Value="3" />
+            <Setter Property="BorderThickness" Value="0" />
+            <Setter Property="Foreground" Value="White" />
+            <Style Selector="^:pointerover">
+                <Setter Property="Background" Value="{DynamicResource SemiBlue6}" />
+            </Style>
+        </Style>
+    </ControlTheme>
 </ResourceDictionary>

src/Ursa/Controls/DateTimePicker/Calendar.cs

@@ -4,6 +4,7 @@ using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
+using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
 
@@ -11,8 +12,9 @@ namespace Ursa.Controls;
 [TemplatePart(PART_PreviousYearButton, typeof(Button))]
 [TemplatePart(PART_NextButton, typeof(Button))]
 [TemplatePart(PART_PreviousButton, typeof(Button))]
+[TemplatePart(PART_YearButton, typeof(Button))]
+[TemplatePart(PART_MonthButton, typeof(Button))]
 [TemplatePart(PART_HeaderButton, typeof(Button))]
-[TemplatePart(PART_BackButton, typeof(Button))]
 [TemplatePart(PART_MonthView, typeof(CalendarMonthView))]
 [TemplatePart(PART_YearView, typeof(CalendarYearView))]
 public class Calendar: TemplatedControl
@@ -21,14 +23,18 @@ public class Calendar: TemplatedControl
     public const string PART_PreviousYearButton = "PART_PreviousYearButton";
     public const string PART_NextButton = "PART_NextButton";
     public const string PART_PreviousButton = "PART_PreviousButton";
-    public const string PART_HeaderButton = "PART_HeaderButton";
+    public const string PART_YearButton = "PART_YearButton";
-    public const string PART_BackButton = "PART_BackButton";
+    public const string PART_MonthButton = "PART_MonthButton";
     public const string PART_MonthView = "PART_MonthView";
     public const string PART_YearView = "PART_YearView";
+    public const string PART_HeaderButton = "PART_HeaderButton";
 
     private CalendarMonthView? _monthView;
     private CalendarYearView? _yearView;
     private DatePickerState _state = DatePickerState.None;
+    private Button? _yearButton;
+    private Button? _monthButton;
+    private Button? _headerButton;
     
     
     public static readonly StyledProperty<DateTime> SelectedDateProperty = AvaloniaProperty.Register<Calendar, DateTime>(nameof(SelectedDate), DateTime.Now);
@@ -73,6 +79,17 @@ public class Calendar: TemplatedControl
         set => SetValue(BlackoutDateRuleProperty, value);
     }
 
+    private bool _isMonthMode = true;
+
+    public static readonly DirectProperty<Calendar, bool> IsMonthModeProperty = AvaloniaProperty.RegisterDirect<Calendar, bool>(
+        nameof(IsMonthMode), o => o.IsMonthMode, (o, v) => o.IsMonthMode = v);
+
+    public bool IsMonthMode
+    {
+        get => _isMonthMode;
+        set => SetAndRaise(IsMonthModeProperty, ref _isMonthMode, value);
+    }
+
     internal DateTime? StartDate;
     internal DateTime? EndDate;
 
@@ -84,13 +101,50 @@ public class Calendar: TemplatedControl
             _monthView.OnDateSelected -= OnDateSelected;
             _monthView.OnDatePreviewed -= OnDatePreviewed;
         }
+
+        if (_yearView is not null)
+        {
+            _yearView.OnMonthSelected -= OnMonthSelected;
+        }
+        Button.ClickEvent.RemoveHandler(OnYearButtonClick, _yearButton);
+        Button.ClickEvent.RemoveHandler(OnMonthButtonClick, _monthButton);
         _monthView = e.NameScope.Find<CalendarMonthView>(PART_MonthView);
         _yearView = e.NameScope.Find<CalendarYearView>(PART_YearView);
+        _yearButton = e.NameScope.Find<Button>(PART_YearButton);
+        _monthButton = e.NameScope.Find<Button>(PART_MonthButton);
+        
         if(_monthView is not null)
         {
             _monthView.OnDateSelected += OnDateSelected;
             _monthView.OnDatePreviewed += OnDatePreviewed;
         }
+
+        if (_yearView is not null)
+        {
+            _yearView.OnMonthSelected += OnMonthSelected;
+        }
+        Button.ClickEvent.AddHandler(OnYearButtonClick, _yearButton);
+        Button.ClickEvent.AddHandler(OnMonthButtonClick, _monthButton);
+    }
+
+    private void OnMonthSelected(object sender, CalendarYearButtonEventArgs e)
+    {
+        SetCurrentValue(IsMonthModeProperty, true);
+    }
+
+    private void OnMonthButtonClick(object sender, RoutedEventArgs e)
+    {
+        SetCurrentValue(IsMonthModeProperty, false);
+        if (_yearView is null) return;
+        _yearView.Mode = CalendarYearViewMode.Month;
+    }
+
+    private void OnYearButtonClick(object sender, RoutedEventArgs e)
+    {
+        if (_yearView is null) return;
+        _yearView.Mode = CalendarYearViewMode.Year;
+        SetCurrentValue(IsMonthModeProperty, false);
+        
     }
 
     private void OnDatePreviewed(object sender, CalendarDayButtonEventArgs e)

src/Ursa/Controls/DateTimePicker/CalendarMonthView.cs

@@ -107,7 +107,10 @@ public class CalendarMonthView : TemplatedControl
     }
     
     
-
+    /// <summary>
+    /// Set day buttons according to context date. 
+    /// </summary>
+    /// <param name="date"></param>
     private void SetDayButtons(DateTime date)
     {
         if (_grid is null) return;
@@ -150,7 +153,6 @@ public class CalendarMonthView : TemplatedControl
                 button.IsNotCurrentMonth = true;
     }
     
-
     public event EventHandler<CalendarDayButtonEventArgs>? OnDateSelected;
     public event EventHandler<CalendarDayButtonEventArgs>? OnDatePreviewed;
 

src/Ursa/Controls/DateTimePicker/CalendarStateMachine.cs

@@ -1,14 +0,0 @@
-namespace Ursa.Controls;
-
-public class CalendarStateMachine
-{
-    
-}
-
-public enum CalendarState
-{
-    PreviewingStartDate,
-    PreviewingEndDate,
-    SelectingStartDate,
-    SelectingEndDate,
-}

src/Ursa/Controls/DateTimePicker/CalendarYearButton.cs

@@ -1,17 +1,25 @@
 using System.Diagnostics;
 using Avalonia.Controls;
+using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Mixins;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Irihi.Avalonia.Shared.Common;
+
 namespace Ursa.Controls;
 
 internal enum CalendarYearViewMode
 {
     Month,
     Year,
-    // The button represents ten year, with one year before and one year after, 12 in total. 
+    // The button represents 10 years. 
     YearRange,
 } 
+
+[PseudoClasses(PC_Range, PseudoClassName.PC_Selected)]
 public class CalendarYearButton: ContentControl
 {
+    public const string PC_Range = ":range";
     static CalendarYearButton()
     {
         PressedMixin.Attach<CalendarYearButton>();
@@ -27,6 +35,15 @@ public class CalendarYearButton: ContentControl
     
     internal CalendarYearViewMode Mode { get; private set; }
     
+    public static readonly RoutedEvent<CalendarYearButtonEventArgs> ItemSelectedEvent = RoutedEvent.Register<CalendarYearButton, CalendarYearButtonEventArgs>(
+        nameof(ItemSelected), RoutingStrategies.Bubble);
+    
+    public event EventHandler<CalendarDayButtonEventArgs> ItemSelected
+    {
+        add => AddHandler(ItemSelectedEvent, value);
+        remove => RemoveHandler(ItemSelectedEvent, value);
+    }
+
     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));
@@ -43,4 +60,12 @@ public class CalendarYearButton: ContentControl
             _ => Content
         };
     }
+
+    protected override void OnPointerPressed(PointerPressedEventArgs e)
+    {
+        base.OnPointerPressed(e);
+        RaiseEvent(new CalendarYearButtonEventArgs(Mode, Year, Month, StartYear, EndYear)
+            { RoutedEvent = ItemSelectedEvent, Source = this });
+
+    }
 }

src/Ursa/Controls/DateTimePicker/CalendarYearButtonEventArgs.cs

@@ -4,5 +4,17 @@ namespace Ursa.Controls;
 
 public class CalendarYearButtonEventArgs: RoutedEventArgs
 {
-    
+    internal int? Year { get; }
+    internal int? Month { get; }
+    internal int? StartYear { get; }
+    internal int? EndYear { get; }
+    internal CalendarYearViewMode Mode { get; }
+    internal CalendarYearButtonEventArgs( CalendarYearViewMode mode, int? year, int? month, int? startYear, int? endYear )
+    {
+        Year = year;
+        Month = month;
+        StartYear = startYear;
+        EndYear = endYear;
+        Mode = mode;
+    }
 }

src/Ursa/Controls/DateTimePicker/CalendarYearView.cs

@@ -2,6 +2,7 @@ using Avalonia.Controls;
 using Avalonia.Controls.Documents;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
+using Irihi.Avalonia.Shared.Helpers;
 
 namespace Ursa.Controls;
 
@@ -15,36 +16,21 @@ namespace Ursa.Controls;
 public class CalendarYearView: TemplatedControl
 {
     public const string PART_Grid = "PART_Grid";
+    private readonly CalendarYearButton[] _buttons = new CalendarYearButton[12];
 
-    private CalendarYearViewMode _mode = CalendarYearViewMode.Month;
+    public event EventHandler<CalendarYearButtonEventArgs>? OnMonthSelected; 
 
-    internal CalendarYearViewMode Mode
+    internal CalendarYearViewMode Mode { get; set; } = CalendarYearViewMode.Month;
-    {
+    internal DateTime ContextDate { get; set; } = DateTime.Today;
-        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)
     {
+        ContextDate = DateTime.Today;
         base.OnApplyTemplate(e);
         _grid = e.NameScope.Find<Grid>(PART_Grid);
         GenerateGridElements();
+        RefreshButtons();
     }
     
     public void GenerateGridElements()
@@ -59,7 +45,43 @@ public class CalendarYearView: TemplatedControl
             var button = new CalendarYearButton();
             Grid.SetRow(button, i / 3);
             Grid.SetColumn(button, i % 3);
+            button.AddHandler(CalendarYearButton.ItemSelectedEvent, OnItemSelected);
             _grid.Children.Add(button);
+            _buttons[i] = button;
+        }
+    }
+    
+    private void OnItemSelected(object sender, CalendarYearButtonEventArgs e)
+    {
+        if (_grid is null) return;
+        var buttons = _grid.Children.OfType<CalendarYearButton>().ToList();
+        if (e.Mode == CalendarYearViewMode.Month)
+        {
+            if (e.Month is null) return;
+            var day = MathHelpers.SafeClamp(e.Month.Value, 0, DateTime.DaysInMonth(ContextDate.Year, e.Month.Value+1));
+            ContextDate = new DateTime(ContextDate.Year, e.Month.Value+1, day+1);
+            OnMonthSelected?.Invoke(this, e);
+        }
+        else if (e.Mode == CalendarYearViewMode.Year)
+        {
+            // Set CalendarYearView to Month mode
+            for (var i = 0; i < 12; i++)
+            {
+                buttons[i].SetValues(CalendarYearViewMode.Month, ContextDate, month: i);
+            }
+            ContextDate = new DateTime(e.Year!.Value, ContextDate.Month, 1);
+            Mode = CalendarYearViewMode.Month;
+        }
+        else if (e.Mode == CalendarYearViewMode.YearRange)
+        {
+            // Set CalendarYearView to Year mode
+            for (var i = 0; i < 12; i++)
+            {
+                if (e.StartYear is null || e.EndYear is null) continue;
+                var year = e.StartYear.Value - 1 + i;
+                buttons[i].SetValues(CalendarYearViewMode.Year, ContextDate, year: year);
+            }
+            Mode = CalendarYearViewMode.Year;
         }
     }
 
@@ -89,4 +111,11 @@ public class CalendarYearView: TemplatedControl
         }
     }
     
+    public void ShiftMode()
+    {
+        if (Mode == CalendarYearViewMode.Month)
+        {
+            
+        }
+    }
 }

src/Ursa/Ursa.csproj

@@ -17,7 +17,7 @@
 
     <ItemGroup>
         <PackageReference Include="Avalonia" Version="$(AvaloniaVersion)"/>
-        <PackageReference Include="Irihi.Avalonia.Shared" Version="0.1.7" />
+        <PackageReference Include="Irihi.Avalonia.Shared" Version="0.1.8" />
     </ItemGroup>
 
     <ItemGroup>