feat: Add theme.

demo/Ursa.Demo/Models/MenuKeys.cs

@@ -1,37 +0,0 @@
-namespace Ursa.Demo;
-
-public static class MenuKeys
-{
-    public const string MenuKeyIntroduction = "Introduction";
-    public const string MenuKeyBadge = "Badge";
-    public const string MenuKeyBanner = "Banner";
-    public const string MenuKeyButtonGroup = "ButtonGroup";
-    public const string MenuKeyBreadcrumb = "Breadcrumb";
-    public const string MenuKeyClassInput = "Class Input";
-    public const string MenuKeyDialog = "Dialog";
-    public const string MenuKeyDivider = "Divider";
-    public const string MenuKeyDisableContainer = "DisableContainer";
-    public const string MenuKeyDrawer = "Drawer";
-    public const string MenuKeyDualBadge = "DualBadge";
-    public const string MenuKeyEnumSelector = "EnumSelector";
-    public const string MenuKeyForm = "Form";
-    public const string MenuKeyImageViewer = "ImageViewer";
-    public const string MenuKeyIpBox = "IPv4Box";
-    public const string MenuKeyIconButton = "IconButton";
-    public const string MenuKeyKeyGestureInput = "KeyGestureInput";
-    public const string MenuKeyLoading = "Loading";
-    public const string MenuKeyMessageBox = "MessageBox";
-    public const string MenuKeyNavMenu = "NavMenu";
-    public const string MenuKeyNumberDisplayer = "NumberDisplayer";
-    public const string MenuKeyNumericUpDown = "NumericUpDown";
-    public const string MenuKeyPagination = "Pagination";
-    public const string MenuKeyRangeSlider = "RangeSlider";
-    public const string MenuKeySelectionList = "SelectionList";
-    public const string MenuKeyTagInput = "TagInput";
-    public const string MenuKeySkeleton = "Skeleton"; 
-    public const string MenuKeyTimeline = "Timeline";
-    public const string MenuKeyTwoTonePathIcon = "TwoTonePathIcon";
-    public const string MenuKeyThemeToggler = "ThemeToggler";
-    public const string MenuKeyToolBar = "ToolBar";
-
-}

demo/Ursa.Demo/Pages/BadgeDemo.axaml

@@ -8,7 +8,7 @@
     d:DesignHeight="850"
     d:DesignWidth="850"
     mc:Ignorable="d">
-    <ScrollViewer HorizontalScrollBarVisibility="Auto" u:ScrollTo.Direction="Top">
+    <ScrollViewer HorizontalScrollBarVisibility="Auto" u:ScrollTo.Direction="Bottom">
         <StackPanel
             Margin="24"
             HorizontalAlignment="Left"

demo/Ursa.Demo/Pages/ScrollToButtonDemo.axaml

@@ -0,0 +1,76 @@
+<UserControl
+    x:Class="Ursa.Demo.Pages.ScrollToButtonDemo"
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:u="https://irihi.tech/ursa"
+    xmlns:vm="clr-namespace:Ursa.Demo.ViewModels"
+    d:DesignHeight="450"
+    d:DesignWidth="800"
+    x:CompileBindings="True"
+    x:DataType="vm:ScrollToButtonDemoViewModel"
+    mc:Ignorable="d">
+    <UserControl.Styles>
+        <Style Selector="ScrollViewer">
+            <Setter Property="Margin" Value="8" />
+        </Style>
+        <Style Selector="ScrollViewer Border.Content">
+            <Setter Property="Background">
+                <Setter.Value>
+                    <LinearGradientBrush StartPoint="0, 0" EndPoint="2000, 2000">
+                        <GradientStop Color="{DynamicResource SemiPurple9Color}" Offset="0.0"></GradientStop>
+                        <GradientStop Color="{DynamicResource SemiPurple5Color}" Offset="0.5"></GradientStop>
+                        <GradientStop Color="{DynamicResource SemiPurple1Color}" Offset="1.0"></GradientStop>
+                    </LinearGradientBrush>
+                </Setter.Value>
+            </Setter>
+        </Style>
+    </UserControl.Styles>
+    <Grid ColumnDefinitions="*, *, *, *, *" RowDefinitions="Auto, *">
+        <TextBlock Grid.Row="0" Grid.Column="0">Scroll To Top</TextBlock>
+        <TextBlock Grid.Row="0" Grid.Column="1">Scroll To Bottom</TextBlock>
+        <TextBlock Grid.Row="0" Grid.Column="2">Scroll To Left</TextBlock>
+        <TextBlock Grid.Row="0" Grid.Column="3">Scroll To Right</TextBlock>
+        <TextBlock Grid.Row="0" Grid.Column="4">Scroll To Top</TextBlock>
+        <ScrollViewer
+            Grid.Row="1"
+            Grid.Column="0"
+            u:ScrollTo.Direction="Top"
+            HorizontalScrollBarVisibility="Disabled"
+            VerticalScrollBarVisibility="Auto">
+            <Border Classes="Content" Height="2000" HorizontalAlignment="Stretch" />
+        </ScrollViewer>
+        <ScrollViewer
+            Grid.Row="1"
+            Grid.Column="1"
+            u:ScrollTo.Direction="Bottom"
+            HorizontalScrollBarVisibility="Disabled"
+            VerticalScrollBarVisibility="Auto">
+            <Border Classes="Content" Height="2000" HorizontalAlignment="Stretch" />
+        </ScrollViewer>
+        <ScrollViewer
+            Grid.Row="1"
+            Grid.Column="2"
+            u:ScrollTo.Direction="Left"
+            HorizontalScrollBarVisibility="Auto"
+            VerticalScrollBarVisibility="Disabled">
+            <Border Classes="Content" Width="2000" VerticalAlignment="Stretch" />
+        </ScrollViewer>
+        <ScrollViewer
+            Grid.Row="1"
+            Grid.Column="3"
+            u:ScrollTo.Direction="Right"
+            HorizontalScrollBarVisibility="Auto"
+            VerticalScrollBarVisibility="Disabled">
+            <Border Classes="Content" Width="2000" VerticalAlignment="Stretch" />
+        </ScrollViewer>
+        <ListBox
+            Grid.Row="1"
+            Grid.Column="4"
+            u:ScrollTo.Direction="Top"
+            ItemsSource="{Binding Items}"
+            ScrollViewer.HorizontalScrollBarVisibility="Disabled"
+            ScrollViewer.VerticalScrollBarVisibility="Auto" />
+    </Grid>
+</UserControl>

demo/Ursa.Demo/Pages/ScrollToButtonDemo.axaml.cs

@@ -0,0 +1,13 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace Ursa.Demo.Pages;
+
+public partial class ScrollToButtonDemo : UserControl
+{
+    public ScrollToButtonDemo()
+    {
+        InitializeComponent();
+    }
+}

demo/Ursa.Demo/Ursa.Demo.csproj

@@ -32,4 +32,8 @@
         <DependentUpon>SkeletonDemo.axaml</DependentUpon>
       </Compile>
     </ItemGroup>
+
+    <ItemGroup>
+      <Folder Include="Models\" />
+    </ItemGroup>
 </Project>

demo/Ursa.Demo/ViewModels/MainViewViewModel.cs

@@ -48,6 +48,7 @@ public class MainViewViewModel : ViewModelBase
             MenuKeys.MenuKeyNumericUpDown => new NumericUpDownDemoViewModel(),
             MenuKeys.MenuKeyPagination => new PaginationDemoViewModel(),
             MenuKeys.MenuKeyRangeSlider => new RangeSliderDemoViewModel(),
+            MenuKeys.MenuKeyScrollToButton => new ScrollToButtonDemoViewModel(),
             MenuKeys.MenuKeySelectionList => new SelectionListDemoViewModel(),
             MenuKeys.MenuKeySkeleton => new SkeletonDemoViewModel(),
             MenuKeys.MenuKeyTagInput => new TagInputDemoViewModel(),

demo/Ursa.Demo/ViewModels/MenuViewModel.cs

@@ -35,6 +35,7 @@ public class MenuViewModel: ViewModelBase
             new() { MenuHeader = "Numeric UpDown", Key = MenuKeys.MenuKeyNumericUpDown },
             new() { MenuHeader = "Pagination", Key = MenuKeys.MenuKeyPagination },
             new() { MenuHeader = "RangeSlider", Key = MenuKeys.MenuKeyRangeSlider },
+            new() { MenuHeader = "ScrollToButton", Key = MenuKeys.MenuKeyScrollToButton, Status = "New" },
             new() { MenuHeader = "Selection List", Key = MenuKeys.MenuKeySelectionList, Status = "New" },
             new() { MenuHeader = "Skeleton", Key = MenuKeys.MenuKeySkeleton, Status = "New" },
             new() { MenuHeader = "TagInput", Key = MenuKeys.MenuKeyTagInput },
@@ -45,3 +46,40 @@ public class MenuViewModel: ViewModelBase
         };
     }
 }
+
+public static class MenuKeys
+{
+    public const string MenuKeyIntroduction = "Introduction";
+    public const string MenuKeyBadge = "Badge";
+    public const string MenuKeyBanner = "Banner";
+    public const string MenuKeyButtonGroup = "ButtonGroup";
+    public const string MenuKeyBreadcrumb= "Breadcrumb";
+    public const string MenuKeyClassInput = "Class Input";
+    public const string MenuKeyDialog = "Dialog";
+    public const string MenuKeyDivider = "Divider";
+    public const string MenuKeyDisableContainer = "DisableContainer";
+    public const string MenuKeyDrawer = "Drawer";
+    public const string MenuKeyDualBadge = "DualBadge";
+    public const string MenuKeyEnumSelector = "EnumSelector";
+    public const string MenuKeyForm = "Form";
+    public const string MenuKeyImageViewer = "ImageViewer";
+    public const string MenuKeyIpBox = "IPv4Box";
+    public const string MenuKeyIconButton = "IconButton";
+    public const string MenuKeyKeyGestureInput = "KeyGestureInput";
+    public const string MenuKeyLoading = "Loading";
+    public const string MenuKeyMessageBox = "MessageBox";
+    public const string MenuKeyNavMenu = "NavMenu";
+    public const string MenuKeyNumberDisplayer = "NumberDisplayer";
+    public const string MenuKeyNumericUpDown = "NumericUpDown";
+    public const string MenuKeyPagination = "Pagination";
+    public const string MenuKeyRangeSlider = "RangeSlider";
+    public const string MenuKeyScrollToButton = "ScrollToButton";
+    public const string MenuKeySelectionList = "SelectionList";
+    public const string MenuKeyTagInput = "TagInput";
+    public const string MenuKeySkeleton = "Skeleton"; 
+    public const string MenuKeyTimeline = "Timeline";
+    public const string MenuKeyTwoTonePathIcon = "TwoTonePathIcon";
+    public const string MenuKeyThemeToggler = "ThemeToggler";
+    public const string MenuKeyToolBar = "ToolBar";
+
+}

demo/Ursa.Demo/ViewModels/ScrollToButtonDemoViewModel.cs

@@ -0,0 +1,15 @@
+using System.Collections.ObjectModel;
+using System.Linq;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace Ursa.Demo.ViewModels;
+
+public class ScrollToButtonDemoViewModel: ObservableObject
+{
+    public ObservableCollection<string> Items { get; set; }
+
+    public ScrollToButtonDemoViewModel()
+    {
+        Items = new ObservableCollection<string>(Enumerable.Range(0, 1000).Select(a => "Item " + a));
+    }
+}

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

@@ -7,7 +7,7 @@
         <Setter Property="HorizontalAlignment" Value="Right" />
         <Setter Property="VerticalAlignment" Value="Bottom" />
         <Setter Property="Cursor" Value="Hand"></Setter>
-        <Setter Property="Margin" Value="0, 0, 32, 32" />
+        <Setter Property="Margin" Value="0, 0, 16, 16" />
         <Setter Property="Template">
             <ControlTemplate TargetType="u:ScrollToButton">
                 <Border
@@ -35,5 +35,14 @@
             <Setter Property="BorderBrush" Value="{DynamicResource ButtonDefaultPressedBorderBrush}" />
             <Setter Property="Background" Value="{DynamicResource ButtonDefaultPressedBackground}" />
         </Style>
+        <Style Selector="^[Direction=Right] /template/ PathIcon#PART_Icon">
+            <Setter Property="RenderTransform" Value="rotate(90deg)"></Setter>
+        </Style>
+        <Style Selector="^[Direction=Bottom] /template/ PathIcon#PART_Icon">
+            <Setter Property="RenderTransform" Value="rotate(180deg)"></Setter>
+        </Style>
+        <Style Selector="^[Direction=Left] /template/ PathIcon#PART_Icon">
+            <Setter Property="RenderTransform" Value="rotate(270deg)"></Setter>
+        </Style>
     </ControlTheme>
 </ResourceDictionary>

src/Ursa/Controls/BackTop/ScrollTo.cs

@@ -2,20 +2,22 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Notifications;
 using Avalonia.Controls.Primitives;
+using Avalonia.Interactivity;
 using Avalonia.Layout;
 using Avalonia.LogicalTree;
 using Avalonia.Styling;
+using Avalonia.VisualTree;
 using Ursa.Common;
 
 namespace Ursa.Controls;
 
 public class ScrollTo
 {
-    public static readonly AttachedProperty<Position> DirectionProperty =
+    public static readonly AttachedProperty<Position?> DirectionProperty =
-        AvaloniaProperty.RegisterAttached<ScrollTo, Control, Position>("Direction");
+        AvaloniaProperty.RegisterAttached<ScrollTo, Control, Position?>("Direction");
 
     public static void SetDirection(Control obj, Position value) => obj.SetValue(DirectionProperty, value);
-    public static Position GetDirection(Control obj) => obj.GetValue(DirectionProperty);
+    public static Position? GetDirection(Control obj) => obj.GetValue(DirectionProperty);
 
     public static readonly AttachedProperty<ControlTheme?> ButtonThemeProperty =
         AvaloniaProperty.RegisterAttached<ScrollTo, Control, ControlTheme?>("ButtonTheme");
@@ -25,7 +27,7 @@ public class ScrollTo
 
     static ScrollTo()
     {
-        DirectionProperty.Changed.AddClassHandler<Control, Position>(OnDirectionChanged);
+        DirectionProperty.Changed.AddClassHandler<Control, Position?>(OnDirectionChanged);
         ButtonThemeProperty.Changed.AddClassHandler<Control, ControlTheme?>(OnButtonThemeChanged);
     }
 
@@ -36,8 +38,9 @@ public class ScrollTo
         button.SetCurrentValue(StyledElement.ThemeProperty, arg2.NewValue.Value);
     }
 
-    private static void OnDirectionChanged(Control control, AvaloniaPropertyChangedEventArgs<Position> args)
+    private static void OnDirectionChanged(Control control, AvaloniaPropertyChangedEventArgs<Position?> args)
     {
+        if (args.NewValue.Value is null) return;
         var button = EnsureButtonInAdorner(control);
         if (button is null) return;
         button.SetCurrentValue(ScrollToButton.DirectionProperty, args.NewValue.Value);
@@ -45,15 +48,13 @@ public class ScrollTo
 
     private static ScrollToButton? EnsureButtonInAdorner(Control control)
     {
-        var scroll = control.GetSelfAndLogicalDescendants().OfType<ScrollViewer>().FirstOrDefault();
+        var adorner = AdornerLayer.GetAdorner(control);
-        if (scroll is null) return null;
-        var adorner = AdornerLayer.GetAdorner(scroll);
         if (adorner is not ScrollToButton button)
         {
             button = new ScrollToButton();
             AdornerLayer.SetAdorner(control, button);
         }
-        button.SetCurrentValue(ScrollToButton.TargetProperty, scroll);
+        button.SetCurrentValue(ScrollToButton.TargetProperty, control);
         button.SetCurrentValue(ScrollToButton.DirectionProperty, GetDirection(control));
         if ( GetButtonTheme(control) is { } theme)
         {

src/Ursa/Controls/BackTop/ScrollToButton.cs

@@ -1,6 +1,8 @@
 using Avalonia;
 using Avalonia.Controls;
+using Avalonia.Interactivity;
 using Avalonia.LogicalTree;
+using Avalonia.VisualTree;
 using Irihi.Avalonia.Shared.Helpers;
 using Ursa.Common;
 
@@ -46,10 +48,11 @@ public class ScrollToButton: Button
         _disposable?.Dispose();
         if (arg2.NewValue.Value is { } newValue)
         {
-            var scroll = newValue.GetSelfAndLogicalDescendants().OfType<ScrollViewer>().FirstOrDefault();
+            var scroll = newValue.GetSelfAndVisualDescendants().OfType<ScrollViewer>().FirstOrDefault();
             if (_scroll is not null)
             {
                 _disposable?.Dispose();
+                _scroll = null;
             }
             _scroll = scroll;
             _disposable = ScrollViewer.OffsetProperty.Changed.AddClassHandler<ScrollViewer, Vector>(OnScrollChanged);
@@ -70,13 +73,14 @@ public class ScrollToButton: Button
         _scroll?.SetCurrentValue(ScrollViewer.OffsetProperty, vector);
     }
     
-    protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
+    protected override void OnLoaded(RoutedEventArgs e)
     {
-        base.OnAttachedToVisualTree(e);
+        base.OnLoaded(e);
-        var scroll = Target.GetSelfAndLogicalDescendants().OfType<ScrollViewer>().FirstOrDefault();
+        var scroll = Target.GetSelfAndVisualDescendants().OfType<ScrollViewer>().FirstOrDefault();
         if (_scroll is not null)
         {
             _disposable?.Dispose();
+            _scroll = null;
         }
         _scroll = scroll;
         _disposable = ScrollViewer.OffsetProperty.Changed.AddClassHandler<ScrollViewer, Vector>(OnScrollChanged);
@@ -91,8 +95,8 @@ public class ScrollToButton: Button
 
     private void SetVisibility(Position direction, Vector? vector)
     {
-        if (vector is null) return;
+        if (vector is null || _scroll is null) return;
-        if (direction == Position.Bottom && vector.Value.Y < 0)
+        if (direction == Position.Bottom && vector.Value.Y < _scroll.Extent.Height - _scroll.Bounds.Height)
         {
             IsVisible = true;
         }
@@ -100,11 +104,11 @@ public class ScrollToButton: Button
         {
             IsVisible = true;
         }
-        else if (direction == Position.Left && vector.Value.X < 0)
+        else if (direction == Position.Left && vector.Value.X > 0)
         {
             IsVisible = true;
         }
-        else if (direction == Position.Right && vector.Value.X > 0)
+        else if (direction == Position.Right && vector.Value.X < _scroll.Extent.Width - _scroll.Bounds.Width)
         {
             IsVisible = true;
         }