feat: add selection list.

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

@@ -0,0 +1,52 @@
+<ResourceDictionary
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:u="https://irihi.tech/ursa">
+    <ControlTheme x:Key="{x:Type u:SelectionList}" TargetType="u:SelectionList">
+        <Setter Property="Background" Value="LightBlue"></Setter>
+        <Setter Property="ListBox.Template">
+            <ControlTemplate TargetType="ListBox">
+                <Border
+                    Name="border"
+                    Background="{TemplateBinding Background}"
+                    BorderBrush="{TemplateBinding BorderBrush}"
+                    BorderThickness="{TemplateBinding BorderThickness}"
+                    ClipToBounds="{TemplateBinding ClipToBounds}"
+                    CornerRadius="{TemplateBinding CornerRadius}">
+                    <Panel>
+                        <Border
+                            Classes="Shadow"
+                            Margin="2"
+                            HorizontalAlignment="Stretch"
+                            VerticalAlignment="Stretch"
+                            Name="{x:Static u:SelectionList.PART_Indicator}"
+                            Theme="{DynamicResource CardBorder}" />
+                        <ItemsPresenter
+                            Name="PART_ItemsPresenter"
+                            Margin="{TemplateBinding Padding}"
+                            ItemsPanel="{TemplateBinding ItemsPanel}" />
+                    </Panel>
+                </Border>
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
+
+    <ControlTheme x:Key="{x:Type u:SelectionListItem}" TargetType="u:SelectionListItem">
+        <Setter Property="Background" Value="Transparent" />
+        <Setter Property="Padding" Value="8" />
+        <Setter Property="Template">
+            <ControlTemplate TargetType="u:SelectionListItem">
+                <ContentPresenter
+                    Name="PART_ContentPresenter"
+                    Padding="{TemplateBinding Padding}"
+                    Foreground="{TemplateBinding Foreground}"
+                    Background="{TemplateBinding Background}"
+                    Content="{TemplateBinding Content}"
+                    ContentTemplate="{TemplateBinding ContentTemplate}" />
+            </ControlTemplate>
+        </Setter>
+        <Style Selector="^:selected">
+            <Setter Property="Foreground" Value="Blue"></Setter>
+        </Style>
+    </ControlTheme>
+</ResourceDictionary>

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

@@ -21,6 +21,7 @@
         <ResourceInclude Source="NumericUpDown.axaml" />
         <ResourceInclude Source="Pagination.axaml" />
         <ResourceInclude Source="RangeSlider.axaml" />
+        <ResourceInclude Source="SelectionList.axaml" />
         <ResourceInclude Source="TagInput.axaml" />
         <ResourceInclude Source="ThemeSelector.axaml" />
         <ResourceInclude Source="Timeline.axaml" />