Merge pull request #339 from irihitech/pagination

Pagination new Theme: TinyPagination

demo/Ursa.Demo/Pages/PaginationDemo.axaml

@@ -28,5 +28,10 @@
 			Command="{Binding LoadPageCommand}"
 			CommandParameter="{Binding $self.CurrentPage}"
             TotalCount="600" />
+        
+        <TextBlock Text="Tiny Pagination"/>
+        <u:Pagination Theme="{DynamicResource TinyPagination}" Command="{Binding LoadPageCommand}"
+                      CommandParameter="{Binding $self.CurrentPage}" PageSize="1"   TotalCount="100" />
+        <u:Pagination Classes="ReadOnly" Theme="{DynamicResource TinyPagination}" TotalCount="100" PageSize="1"/>
     </StackPanel>
 </UserControl>

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

@@ -12,7 +12,7 @@
         <Setter Property="Template">
             <ControlTemplate TargetType="u:Pagination">
                 <StackPanel Orientation="Horizontal">
-                    <u:PaginationButton u:DisabledAdorner.IsEnabled="True" Name="{x:Static u:Pagination.PART_PreviousButton}">
+                    <u:PaginationButton Name="{x:Static u:Pagination.PART_PreviousButton}" u:DisabledAdorner.IsEnabled="True">
                         <PathIcon
                             Width="12"
                             Height="12"
@@ -20,21 +20,24 @@
                             Foreground="{DynamicResource PaginationButtonIconForeground}" />
                     </u:PaginationButton>
                     <StackPanel Name="{x:Static u:Pagination.PART_ButtonPanel}" Orientation="Horizontal" />
-                    <u:PaginationButton u:DisabledAdorner.IsEnabled="True" Name="{x:Static u:Pagination.PART_NextButton}">
+                    <u:PaginationButton Name="{x:Static u:Pagination.PART_NextButton}" u:DisabledAdorner.IsEnabled="True">
                         <PathIcon
                             Width="12"
                             Height="12"
                             Data="{DynamicResource PaginationForwardGlyph}"
                             Foreground="{DynamicResource PaginationButtonIconForeground}" />
                     </u:PaginationButton>
-                    <StackPanel Orientation="Horizontal" IsVisible="{TemplateBinding ShowQuickJump}">
+                    <StackPanel IsVisible="{TemplateBinding ShowQuickJump}" Orientation="Horizontal">
                         <TextBlock
-                            Margin="4 0"
+                            Margin="4,0"
                             VerticalAlignment="Center"
                             Text="{DynamicResource STRING_PAGINATION_JUMP_TO}" />
-                        <u:NumericIntUpDown x:Name="{x:Static u:Pagination.PART_QuickJumpInput}" ShowButtonSpinner="False" Width="50"></u:NumericIntUpDown>
+                        <u:NumericIntUpDown
+                            x:Name="{x:Static u:Pagination.PART_QuickJumpInput}"
+                            Width="50"
+                            ShowButtonSpinner="False" />
                         <TextBlock
-                            Margin="4 0"
+                            Margin="4,0"
                             VerticalAlignment="Center"
                             Text="{DynamicResource STRING_PAGINATION_PAGE}" />
                     </StackPanel>
@@ -48,6 +51,63 @@
         </Setter>
     </ControlTheme>
 
+    <ControlTheme x:Key="TinyPagination" TargetType="{x:Type u:Pagination}">
+        <Setter Property="DisplayCurrentPageInQuickJumper" Value="True"></Setter>
+        <Setter Property="Template">
+            <ControlTemplate TargetType="u:Pagination">
+                <StackPanel Orientation="Horizontal">
+                    <u:PaginationButton Name="{x:Static u:Pagination.PART_PreviousButton}" u:DisabledAdorner.IsEnabled="True">
+                        <PathIcon
+                            Width="12"
+                            Height="12"
+                            Data="{DynamicResource PaginationBackwardGlyph}"
+                            Foreground="{DynamicResource PaginationButtonIconForeground}" />
+                    </u:PaginationButton>
+                    <Grid ColumnDefinitions="*, Auto, *">
+                        <u:NumericIntUpDown
+                            Name="{x:Static u:Pagination.PART_QuickJumpInput}"
+                            Grid.Column="0"
+                            MinWidth="{Binding $self.Bounds.Height}"
+                            VerticalAlignment="Center"
+                            HorizontalContentAlignment="Center"
+                            ShowButtonSpinner="False"
+                            IsVisible="True"
+                            Value="{TemplateBinding CurrentPage,
+                                                    Mode=TwoWay}" />
+                        <TextBlock
+                            Name="PART_PageTextBlock"
+                            Grid.Column="0"
+                            VerticalAlignment="Center"
+                            IsVisible="False"
+                            Text="{TemplateBinding CurrentPage}" />
+                        <TextBlock
+                            Grid.Column="1"
+                            Margin="8,0"
+                            VerticalAlignment="Center"
+                            Text="/" />
+                        <SelectableTextBlock
+                            Grid.Column="2"
+                            VerticalAlignment="Center"
+                            Text="{TemplateBinding PageCount}" />
+                    </Grid>
+                    <u:PaginationButton Name="{x:Static u:Pagination.PART_NextButton}" u:DisabledAdorner.IsEnabled="True">
+                        <PathIcon
+                            Width="12"
+                            Height="12"
+                            Data="{DynamicResource PaginationForwardGlyph}"
+                            Foreground="{DynamicResource PaginationButtonIconForeground}" />
+                    </u:PaginationButton>
+                </StackPanel>
+            </ControlTemplate>
+        </Setter>
+        <Style Selector="^.ReadOnly /template/ TextBlock#PART_PageTextBlock">
+            <Setter Property="IsVisible" Value="True" />
+        </Style>
+        <Style Selector="^.ReadOnly /template/ u|NumericUpDown#PART_QuickJumpInput">
+            <Setter Property="IsVisible" Value="False" />
+        </Style>
+    </ControlTheme>
+
     <ControlTheme x:Key="{x:Type u:PaginationButton}" TargetType="u:PaginationButton">
         <Setter Property="Content" Value="{Binding $self.Page}" />
         <Setter Property="BorderBrush" Value="Transparent" />
@@ -130,4 +190,4 @@
         </Style>
     </ControlTheme>
 
-</ResourceDictionary>
+</ResourceDictionary>

src/Ursa/Controls/Pagination/Pagination.cs

@@ -1,3 +1,4 @@
+using System.Windows.Input;
 using Avalonia;
 using Avalonia.Collections;
 using Avalonia.Controls;
@@ -7,154 +8,75 @@ using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Styling;
 using Irihi.Avalonia.Shared.Helpers;
-using System.Windows.Input;
 
 namespace Ursa.Controls;
 
 /// <summary>
-/// Pagination is a control that displays a series of buttons that can be used to navigate to pages.
+///     Pagination is a control that displays a series of buttons that can be used to navigate to pages.
-/// CurrentPage starts from 1.
+///     CurrentPage starts from 1.
-/// Pagination only stores an approximate index internally.
+///     Pagination only stores an approximate index internally.
 /// </summary>
 [TemplatePart(PART_PreviousButton, typeof(PaginationButton))]
 [TemplatePart(PART_NextButton, typeof(PaginationButton))]
 [TemplatePart(PART_ButtonPanel, typeof(StackPanel))]
 [TemplatePart(PART_QuickJumpInput, typeof(NumericIntUpDown))]
-public class Pagination: TemplatedControl
+public class Pagination : TemplatedControl
 {
     public const string PART_PreviousButton = "PART_PreviousButton";
     public const string PART_NextButton = "PART_NextButton";
     public const string PART_ButtonPanel = "PART_ButtonPanel";
     public const string PART_QuickJumpInput = "PART_QuickJumpInput";
-    private PaginationButton? _previousButton;
-    private PaginationButton? _nextButton;
-    private StackPanel? _buttonPanel;
-    private readonly PaginationButton[] _buttons = new PaginationButton[7];
-    private NumericIntUpDown? _quickJumpInput;
 
     public static readonly StyledProperty<int?> CurrentPageProperty = AvaloniaProperty.Register<Pagination, int?>(
-        nameof(CurrentPage));
+        nameof(CurrentPage), coerce: CoerceCurrentPage);
-
-    public int? CurrentPage
-    {
-        get => GetValue(CurrentPageProperty);
-        set => SetValue(CurrentPageProperty, value);
-    }
-
-    private void OnCurrentPageChanged(AvaloniaPropertyChangedEventArgs<int?> args)
-    {
-        int? oldValue = args.GetOldValue<int?>();
-        int? newValue = args.GetNewValue<int?>();
-        var e = new ValueChangedEventArgs<int>(CurrentPageChangedEvent, oldValue, newValue);
-        RaiseEvent(e);
-    }
 
     public static readonly RoutedEvent<ValueChangedEventArgs<int>> CurrentPageChangedEvent =
-        RoutedEvent.Register<Pagination, ValueChangedEventArgs<int>>(nameof(CurrentPageChanged), RoutingStrategies.Bubble);
+        RoutedEvent.Register<Pagination, ValueChangedEventArgs<int>>(nameof(CurrentPageChanged),
-
+            RoutingStrategies.Bubble);
-    /// <summary>
-    /// Raised when the <see cref="CurrentPage"/> changes.
-    /// </summary>
-    public event EventHandler<ValueChangedEventArgs<int>>? CurrentPageChanged
-    {
-        add => AddHandler(CurrentPageChangedEvent, value);
-        remove => RemoveHandler(CurrentPageChangedEvent, value);
-    }
 
     public static readonly StyledProperty<ICommand?> CommandProperty = AvaloniaProperty.Register<Pagination, ICommand?>(
         nameof(Command));
 
-    public ICommand? Command
+    public static readonly StyledProperty<object?> CommandParameterProperty =
-    {
+        AvaloniaProperty.Register<Pagination, object?>(nameof(CommandParameter));
-        get => GetValue(CommandProperty);
-        set => SetValue(CommandProperty, value);
-    }
-
-    public static readonly StyledProperty<object?> CommandParameterProperty = AvaloniaProperty.Register<Pagination, object?>(nameof(CommandParameter));
-
-    public object? CommandParameter
-    {
-        get => this.GetValue(CommandParameterProperty);
-        set => this.SetValue(CommandParameterProperty, value);
-    }
 
     public static readonly StyledProperty<int> TotalCountProperty = AvaloniaProperty.Register<Pagination, int>(
         nameof(TotalCount));
 
-    /// <summary>
-    /// Total count of items. 
-    /// </summary>
-    public int TotalCount
-    {
-        get => GetValue(TotalCountProperty);
-        set => SetValue(TotalCountProperty, value);
-    }
-
     public static readonly StyledProperty<int> PageSizeProperty = AvaloniaProperty.Register<Pagination, int>(
-        nameof(PageSize), defaultValue: 10);
+        nameof(PageSize), 10);
 
-    /// <summary>
+    public static readonly DirectProperty<Pagination, int> PageCountProperty =
-    /// Page size.
+        AvaloniaProperty.RegisterDirect<Pagination, int>(
-    /// </summary>
+            nameof(PageCount), o => o.PageCount, (o, e) => o.PageCount = e);
-    public int PageSize
-    {
-        get => GetValue(PageSizeProperty);
-        set => SetValue(PageSizeProperty, value);
-    }
 
-    private int _pageCount;
+    public static readonly StyledProperty<AvaloniaList<int>> PageSizeOptionsProperty =
+        AvaloniaProperty.Register<Pagination, AvaloniaList<int>>(
+            nameof(PageSizeOptions));
 
-    public static readonly DirectProperty<Pagination, int> PageCountProperty = AvaloniaProperty.RegisterDirect<Pagination, int>(
+    public static readonly StyledProperty<ControlTheme> PageButtonThemeProperty =
-        nameof(PageCount), o => o.PageCount);
+        AvaloniaProperty.Register<Pagination, ControlTheme>(
+            nameof(PageButtonTheme));
 
-    /// <summary>
+    public static readonly StyledProperty<bool> ShowPageSizeSelectorProperty =
-    /// Page count.
+        AvaloniaProperty.Register<Pagination, bool>(
-    /// </summary>
+            nameof(ShowPageSizeSelector));
-    public int PageCount
-    {
-        get => _pageCount;
-        private set => SetAndRaise(PageCountProperty, ref _pageCount, value);
-    }
-
-    public static readonly StyledProperty<AvaloniaList<int>> PageSizeOptionsProperty = AvaloniaProperty.Register<Pagination, AvaloniaList<int>>(
-        nameof(PageSizeOptions));
-
-    public AvaloniaList<int> PageSizeOptions
-    {
-        get => GetValue(PageSizeOptionsProperty);
-        set => SetValue(PageSizeOptionsProperty, value);
-    }
-
-    public static readonly StyledProperty<ControlTheme> PageButtonThemeProperty = AvaloniaProperty.Register<Pagination, ControlTheme>(
-        nameof(PageButtonTheme));
-
-    public ControlTheme PageButtonTheme
-    {
-        get => GetValue(PageButtonThemeProperty);
-        set => SetValue(PageButtonThemeProperty, value);
-    }
-
-    public static readonly StyledProperty<bool> ShowPageSizeSelectorProperty = AvaloniaProperty.Register<Pagination, bool>(
-        nameof(ShowPageSizeSelector));
-
-    public bool ShowPageSizeSelector
-    {
-        get => GetValue(ShowPageSizeSelectorProperty);
-        set => SetValue(ShowPageSizeSelectorProperty, value);
-    }
 
     public static readonly StyledProperty<bool> ShowQuickJumpProperty = AvaloniaProperty.Register<Pagination, bool>(
         nameof(ShowQuickJump));
 
-    public bool ShowQuickJump
+    private readonly PaginationButton[] _buttons = new PaginationButton[7];
-    {
+    private StackPanel? _buttonPanel;
-        get => GetValue(ShowQuickJumpProperty);
+    private PaginationButton? _nextButton;
-        set => SetValue(ShowQuickJumpProperty, value);
+
-    }
+    private int _pageCount;
+    private PaginationButton? _previousButton;
+    private NumericIntUpDown? _quickJumpInput;
 
     static Pagination()
     {
-        PageSizeProperty.Changed.AddClassHandler<Pagination, int>((pagination, args) => pagination.OnPageSizeChanged(args));
+        PageSizeProperty.Changed.AddClassHandler<Pagination, int>((pagination, args) =>
+            pagination.OnPageSizeChanged(args));
         CurrentPageProperty.Changed.AddClassHandler<Pagination, int?>((pagination, args) =>
             pagination.UpdateButtonsByCurrentPage(args.NewValue.Value));
         CurrentPageProperty.Changed.AddClassHandler<Pagination, int?>((pagination, args) =>
@@ -163,19 +85,119 @@ public class Pagination: TemplatedControl
             pagination.UpdateButtonsByCurrentPage(pagination.CurrentPage));
     }
 
+    public int? CurrentPage
+    {
+        get => GetValue(CurrentPageProperty);
+        set => SetValue(CurrentPageProperty, value);
+    }
+
+    public ICommand? Command
+    {
+        get => GetValue(CommandProperty);
+        set => SetValue(CommandProperty, value);
+    }
+
+    public object? CommandParameter
+    {
+        get => GetValue(CommandParameterProperty);
+        set => SetValue(CommandParameterProperty, value);
+    }
+
+    /// <summary>
+    ///     Total count of items.
+    /// </summary>
+    public int TotalCount
+    {
+        get => GetValue(TotalCountProperty);
+        set => SetValue(TotalCountProperty, value);
+    }
+
+    /// <summary>
+    ///     Page size.
+    /// </summary>
+    public int PageSize
+    {
+        get => GetValue(PageSizeProperty);
+        set => SetValue(PageSizeProperty, value);
+    }
+
+    /// <summary>
+    ///     Page count.
+    /// </summary>
+    public int PageCount
+    {
+        get => _pageCount;
+        private set => SetAndRaise(PageCountProperty, ref _pageCount, value);
+    }
+
+    public AvaloniaList<int> PageSizeOptions
+    {
+        get => GetValue(PageSizeOptionsProperty);
+        set => SetValue(PageSizeOptionsProperty, value);
+    }
+
+    public ControlTheme PageButtonTheme
+    {
+        get => GetValue(PageButtonThemeProperty);
+        set => SetValue(PageButtonThemeProperty, value);
+    }
+
+    public bool ShowPageSizeSelector
+    {
+        get => GetValue(ShowPageSizeSelectorProperty);
+        set => SetValue(ShowPageSizeSelectorProperty, value);
+    }
+
+    public bool ShowQuickJump
+    {
+        get => GetValue(ShowQuickJumpProperty);
+        set => SetValue(ShowQuickJumpProperty, value);
+    }
+
+    public static readonly StyledProperty<bool> DisplayCurrentPageInQuickJumperProperty = AvaloniaProperty.Register<Pagination, bool>(
+        nameof(DisplayCurrentPageInQuickJumper));
+
+    public bool DisplayCurrentPageInQuickJumper
+    {
+        get => GetValue(DisplayCurrentPageInQuickJumperProperty);
+        set => SetValue(DisplayCurrentPageInQuickJumperProperty, value);
+    }
+
+    private static int? CoerceCurrentPage(AvaloniaObject arg1, int? arg2)
+    {
+        if (arg2 is null) return null;
+        if (arg1 is Pagination p) arg2 = MathHelpers.SafeClamp(arg2.Value, 1, p.PageCount);
+        return arg2;
+    }
+
+    private void OnCurrentPageChanged(AvaloniaPropertyChangedEventArgs<int?> args)
+    {
+        var oldValue = args.GetOldValue<int?>();
+        var newValue = args.GetNewValue<int?>();
+        var e = new ValueChangedEventArgs<int>(CurrentPageChangedEvent, oldValue, newValue);
+        if (DisplayCurrentPageInQuickJumper)
+        {
+            _quickJumpInput?.SetCurrentValue(NumericIntUpDown.ValueProperty, newValue);
+        }
+        RaiseEvent(e);
+    }
+
+    /// <summary>
+    ///     Raised when the <see cref="CurrentPage" /> changes.
+    /// </summary>
+    public event EventHandler<ValueChangedEventArgs<int>>? CurrentPageChanged
+    {
+        add => AddHandler(CurrentPageChangedEvent, value);
+        remove => RemoveHandler(CurrentPageChangedEvent, value);
+    }
+
     private void OnPageSizeChanged(AvaloniaPropertyChangedEventArgs<int> args)
     {
-        int pageCount = TotalCount / args.NewValue.Value;
+        var pageCount = TotalCount / args.NewValue.Value;
-        int residue = TotalCount % args.NewValue.Value;
+        var residue = TotalCount % args.NewValue.Value;
-        if (residue > 0)
+        if (residue > 0) pageCount++;
-        {
-            pageCount++;
-        }
         PageCount = pageCount;
-        if (CurrentPage > PageCount)
+        if (CurrentPage > PageCount) CurrentPage = null;
-        {
-            CurrentPage = null;
-        }
         UpdateButtonsByCurrentPage(CurrentPage);
     }
 
@@ -201,10 +223,7 @@ public class Pagination: TemplatedControl
 
     private void OnQuickJumpInputKeyDown(object? sender, KeyEventArgs e)
     {
-        if (e.Key is Key.Enter or Key.Return)
+        if (e.Key is Key.Enter or Key.Return) SyncQuickJumperValue();
-        {
-            SyncQuickJumperValue();
-        }
     }
 
     private void OnQuickJumpInputLostFocus(object? sender, RoutedEventArgs e)
@@ -219,7 +238,10 @@ public class Pagination: TemplatedControl
         if (value is null) return;
         value = Clamp(value.Value, 1, PageCount);
         SetCurrentValue(CurrentPageProperty, value);
-        _quickJumpInput?.SetCurrentValue(NumericIntUpDown.ValueProperty, null);
+        if (!DisplayCurrentPageInQuickJumper)
+        {
+            _quickJumpInput?.SetCurrentValue(NumericIntUpDown.ValueProperty, null);
+        }
         InvokeCommand();
     }
 
@@ -234,9 +256,9 @@ public class Pagination: TemplatedControl
     {
         if (_buttonPanel is null) return;
         _buttonPanel.Children.Clear();
-        for (int i = 1; i <= 7; i++)
+        for (var i = 1; i <= 7; i++)
         {
-            var button = new PaginationButton() { Page = i, IsVisible = true };
+            var button = new PaginationButton { Page = i, IsVisible = true };
             _buttonPanel.Children.Add(button);
             _buttons[i - 1] = button;
             Button.ClickEvent.AddHandler(OnPageButtonClick, button);
@@ -248,24 +270,19 @@ public class Pagination: TemplatedControl
         if (sender is PaginationButton pageButton)
         {
             if (pageButton.IsFastForward)
-            {
                 AddCurrentPage(-5);
-            }
             else if (pageButton.IsFastBackward)
-            {
                 AddCurrentPage(5);
-            }
             else
-            {
                 CurrentPage = pageButton.Page;
-            }
         }
+
         InvokeCommand();
     }
 
     private void AddCurrentPage(int pageChange)
     {
-        int newValue = (CurrentPage ?? 0) + pageChange;
+        var newValue = (CurrentPage ?? 0) + pageChange;
         newValue = Clamp(newValue, 1, PageCount);
         SetCurrentValue(CurrentPageProperty, newValue);
     }
@@ -276,26 +293,26 @@ public class Pagination: TemplatedControl
     }
 
     /// <summary>
-    /// Update Button Content and Visibility by current page.
+    ///     Update Button Content and Visibility by current page.
     /// </summary>
     /// <param name="page"></param>
     private void UpdateButtonsByCurrentPage(int? page)
     {
-        if (_buttonPanel is null) return;
         if (PageSize == 0) return;
-
+        var pageCount = TotalCount / PageSize;
-        int? currentPage = CurrentPage;
+        if (_buttonPanel is null)
-        int pageCount = TotalCount / PageSize;
-        int residue = TotalCount % PageSize;
-        if (residue > 0)
         {
-            pageCount++;
+            SetCurrentValue(PageCountProperty, pageCount);
+            return;
         }
 
+        var currentPage = CurrentPage;
+        var residue = TotalCount % PageSize;
+        if (residue > 0) pageCount++;
+
         if (pageCount <= 7)
         {
-            for (int i = 0; i < 7; i++)
+            for (var i = 0; i < 7; i++)
-            {
                 if (i < pageCount)
                 {
                     _buttons[i].IsVisible = true;
@@ -305,15 +322,11 @@ public class Pagination: TemplatedControl
                 {
                     _buttons[i].IsVisible = false;
                 }
-            }
         }
         else
         {
-            for (int i = 0; i < 7; i++)
+            for (var i = 0; i < 7; i++) _buttons[i].IsVisible = true;
-            {
+            var mid = currentPage ?? 0;
-                _buttons[i].IsVisible = true;
-            }
-            int mid = currentPage ?? 0;
             mid = Clamp(mid, 4, pageCount - 3);
             _buttons[3].Page = mid;
             _buttons[2].Page = mid - 1;
@@ -321,45 +334,29 @@ public class Pagination: TemplatedControl
             _buttons[0].Page = 1;
             _buttons[6].Page = pageCount;
             if (mid > 4)
-            {
                 _buttons[1].SetStatus(-1, false, true, false);
-            }
             else
-            {
                 _buttons[1].SetStatus(mid - 2, false, false, false);
-            }
             if (mid < pageCount - 3)
-            {
                 _buttons[5].SetStatus(-1, false, false, true);
-            }
             else
-            {
                 _buttons[5].SetStatus(mid + 2, false, false, false);
-            }
 
             foreach (var button in _buttons)
-            {
                 if (button.Page == currentPage)
-                {
                     button.SetSelected(true);
-                }
                 else
-                {
                     button.SetSelected(false);
-                }
-            }
         }
 
-        PageCount = pageCount;
+        SetCurrentValue(PageCountProperty, pageCount);
         SetCurrentValue(CurrentPageProperty, currentPage);
         if (_previousButton != null) _previousButton.IsEnabled = (CurrentPage ?? int.MaxValue) > 1;
         if (_nextButton != null) _nextButton.IsEnabled = (CurrentPage ?? 0) < PageCount;
     }
+
     private void InvokeCommand()
     {
-        if (this.Command != null && this.Command.CanExecute(this.CommandParameter))
+        if (Command != null && Command.CanExecute(CommandParameter)) Command.Execute(CommandParameter);
-        {
-            this.Command.Execute(this.CommandParameter);
-        }
     }
 }

src/Ursa/Controls/Pagination/PaginationButton.cs

@@ -5,7 +5,7 @@ using Avalonia.Controls.Metadata;
 namespace Ursa.Controls;
 
 [PseudoClasses(PC_Left, PC_Right, PC_Selected)]
-public class PaginationButton: Button
+public class PaginationButton: RepeatButton
 {
     public const string PC_Left = ":left";
     public const string PC_Right = ":right";