feat: make UrsaView base.

demo/Ursa.Demo/App.axaml.cs

@@ -1,4 +1,5 @@
 using Avalonia;
+using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Ursa.Demo.ViewModels;
@@ -17,8 +18,9 @@ public partial class App : Application
     {
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
-            desktop.MainWindow = new MainWindow()
+            desktop.MainWindow = new Window()
             {
+                Content = new SingleView(),
                 DataContext = new MainViewViewModel(),
             };
         }

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

@@ -20,12 +20,13 @@
                             VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                             Content="{TemplateBinding Content}"
                             ContentTemplate="{TemplateBinding ContentTemplate}" />
-                        <u:TitleBar
+                        <Grid ColumnDefinitions="Auto, *, Auto"
                             VerticalAlignment="Top"
-                            Content="{Binding $parent[u:UrsaWindow].TitleBarContent}"
-                            Margin="{Binding $parent[u:UrsaWindow].TitleBarMargin}"
-                            LeftContent="{Binding $parent[u:UrsaWindow].LeftContent}"
-                            RightContent="{Binding $parent[u:UrsaWindow].RightContent}" />
+                            Margin="{Binding $parent[u:UrsaWindow].TitleBarMargin}">
+                            <ContentPresenter Grid.Column="0" Content="{TemplateBinding LeftContent}" VerticalAlignment="Center"/>
+                            <ContentPresenter Grid.Column="1" Content="{TemplateBinding TitleBarContent}" VerticalAlignment="Center"/>
+                            <ContentPresenter Grid.Column="2" Content="{TemplateBinding RightContent}" VerticalAlignment="Center"/>
+                        </Grid>
                         <u:OverlayDialogHost IsModalStatusReporter="True" />
                     </Panel>
                 </Panel>

src/Ursa.Themes.Semi/Styles/UrsaView.axaml

@@ -0,0 +1,14 @@
+<Styles xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:u="https://irihi.tech/ursa">
+    <Design.PreviewWith>
+        <Border Padding="20">
+            <!-- Add Controls for Previewer Here -->
+        </Border>
+    </Design.PreviewWith>
+
+    <!-- Add Styles Here -->
+    <Style Selector=":is(u|UrsaView)">
+        <Setter Property="Theme" Value="{DynamicResource {x:Type u:UrsaView}}"/>
+    </Style>
+</Styles>

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

@@ -10,5 +10,6 @@
     <StyleInclude Source="Skeleton.axaml" />
     <StyleInclude Source="ToolBar.axaml"/>
     <StyleInclude Source="TimeBox.axaml"/>
+    <StyleInclude Source="UrsaView.axaml" />
     <!--  Add Styles Here  -->
 </Styles>