integrate groupbox control

samples/ControlCatalog/MainView.xaml

@@ -57,6 +57,7 @@
       <TabItem Header="TextBlock"><pages:TextBlockPage/></TabItem>
       <TabItem Header="ToolTip"><pages:ToolTipPage/></TabItem>
       <TabItem Header="TreeView"><pages:TreeViewPage/></TabItem>
+      <TabItem Header="GroupBox"><pages:GroupBoxPage/></TabItem>
       <TabItem Header="Viewbox"><pages:ViewboxPage/></TabItem>
       <TabControl.Tag>
         <StackPanel Width="115" Spacing="4" HorizontalAlignment="Right" VerticalAlignment="Bottom" Margin="8">

samples/ControlCatalog/Pages/GroupBoxPage.xaml

@@ -0,0 +1,13 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             x:Class="ControlCatalog.Pages.GroupBoxPage">
+  <StackPanel Orientation="Vertical" Spacing="4">
+    <TextBlock Classes="h1">GroupBox</TextBlock>
+    <TextBlock Classes="h2">A group box control</TextBlock>
+
+    <GroupBox Margin="10" Header="Title" Width="200">
+      <TextBlock Text="Group box content"/>
+    </GroupBox>
+
+  </StackPanel>
+</UserControl>

samples/ControlCatalog/Pages/GroupBoxPage.xaml.cs

@@ -0,0 +1,19 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace ControlCatalog.Pages
+{
+    public class GroupBoxPage : UserControl
+    {
+        public GroupBoxPage()
+        {
+            this.InitializeComponent();
+        }
+
+        private void InitializeComponent()
+        {
+            AvaloniaXamlLoader.Load(this);
+        }
+    }
+}

src/Avalonia.Controls/GroupBox.cs

@@ -0,0 +1,23 @@
+using Avalonia.Controls.Primitives;
+using Avalonia.Input;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// GroupBox Control class
+    /// </summary>
+    public class GroupBox: HeaderedContentControl
+    {
+        /// <summary>
+        /// override some metadata:
+        /// Focusable: false
+        /// TabNavigation: None
+        /// </summary>
+        static GroupBox()
+        {
+            FocusableProperty.OverrideMetadata<GroupBox>(new StyledPropertyMetadata<bool>(false));
+            KeyboardNavigation.TabNavigationProperty.OverrideMetadata<GroupBox>
+                (new StyledPropertyMetadata<KeyboardNavigationMode>(KeyboardNavigationMode.None));
+        }
+    }
+}

src/Avalonia.Themes.Default/DefaultTheme.xaml

@@ -52,4 +52,5 @@
   <StyleInclude Source="resm:Avalonia.Themes.Default.WindowNotificationManager.xaml?assembly=Avalonia.Themes.Default"/>
   <StyleInclude Source="resm:Avalonia.Themes.Default.NotificationCard.xaml?assembly=Avalonia.Themes.Default"/>
   <StyleInclude Source="resm:Avalonia.Themes.Default.NativeMenuBar.xaml?assembly=Avalonia.Themes.Default"/>
+  <StyleInclude Source="resm:Avalonia.Themes.Default.GroupBox.xaml?assembly=Avalonia.Themes.Default"/>
 </Styles>

src/Avalonia.Themes.Default/GroupBox.xaml

@@ -0,0 +1,60 @@
+<Styles
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    >
+
+  <Styles.Resources>
+    <Thickness x:Key="GroupBoxHeaderThemePadding">4</Thickness>
+  </Styles.Resources>
+
+  <Style Selector="GroupBox">
+    <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource ThemeAccentBrush}" />
+    <Setter Property="BorderThickness" Value="1" />
+    <Setter Property="FontSize" Value="{DynamicResource FontSizeNormal}" />
+    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}" />
+    <Setter Property="Padding" Value="4" />
+    <Setter Property="Margin" Value="1" />
+    <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
+
+    <Setter Property="Template">
+      <Setter.Value>
+        <ControlTemplate>
+          <Grid x:Name="GroupBoxRoot">
+            <Grid.RowDefinitions>
+              <RowDefinition Height="Auto" />
+              <RowDefinition Height="*" />
+            </Grid.RowDefinitions>
+            <Border x:Name="HeaderSite"
+                    Grid.Row="0"
+                    Background="{TemplateBinding Background}"
+                    BorderBrush="{TemplateBinding BorderBrush}"
+                    BorderThickness="{TemplateBinding BorderThickness}"
+                    UseLayoutRounding="True">
+              <ContentControl x:Name="HeaderContent"
+                                         Margin="{DynamicResource GroupBoxHeaderThemePadding}"
+                                         Content="{TemplateBinding Header}"
+                                         ContentTemplate="{TemplateBinding HeaderTemplate}"
+                                         FontFamily="{TemplateBinding FontFamily}"
+                                         FontSize="{TemplateBinding FontSize}"
+                                         FontWeight="{TemplateBinding FontWeight}"
+                                         UseLayoutRounding="False" />
+            </Border>
+            <Border Grid.Row="1"
+                    Background="Transparent"
+                    BorderBrush="{TemplateBinding BorderBrush}"
+                    BorderThickness="{Binding RelativeSource={RelativeSource TemplatedParent},
+                                                                        Path=BorderThickness}"
+                    UseLayoutRounding="True">
+              <ContentPresenter Margin="{TemplateBinding Padding}"
+                                Content="{TemplateBinding Content}"
+                                ContentTemplate="{TemplateBinding ContentTemplate}"
+                                Cursor="{TemplateBinding Cursor}"
+                                UseLayoutRounding="False" />
+            </Border>
+          </Grid>
+        </ControlTemplate>
+      </Setter.Value>
+    </Setter>
+  </Style>
+</Styles>