Start styling the clone repo expander

http://blog.ninlabs.com/2011/04/keeping-it-simple-customizing-the-wpf-expander-icon/

Author: donokuda

src/GitHub.VisualStudio/UI/Views/Controls/RepositoryCloneControl.xaml

@@ -46,7 +46,68 @@
         <Setter Property="Margin"
                 Value="0" />
       </Style>
-    </DockPanel.Resources>
+
+            <Style x:Key="ExpanderDownHeaderStyle" TargetType="{x:Type ToggleButton}">
+                <Setter Property="Template">
+                    <Setter.Value>
+                        <ControlTemplate TargetType="{x:Type ToggleButton}">
+                            <Border Padding="{TemplateBinding Padding}">
+                                <StackPanel Orientation="Horizontal">
+                                    <TextBlock x:Name="arrow" Text="Foobar" Foreground="Red" />
+                                </StackPanel>
+                            </Border>
+
+                            <ControlTemplate.Triggers>
+                                <Trigger Property="IsChecked" Value="True">
+                                    <Setter Property="Foreground" TargetName="arrow" Value="Blue" />
+                                </Trigger>
+                            </ControlTemplate.Triggers>
+                        </ControlTemplate>
+                    </Setter.Value>
+                </Setter>
+            </Style>
+
+            <Style x:Key="ExpanderHeaderFocusVisual">
+                <Setter Property="Control.Template">
+                    <Setter.Value>
+                        <ControlTemplate>
+                            <Border>
+                                <Rectangle Margin="0" SnapsToDevicePixels="true" Stroke="Black" StrokeThickness="1" StrokeDashArray="1 2"/>
+                            </Border>
+                        </ControlTemplate>
+                    </Setter.Value>
+                </Setter>
+            </Style>
+
+            <Style x:Key="StatusGroupExpander" TargetType="{x:Type Expander}">
+                <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
+                <Setter Property="Background" Value="Transparent"/>
+                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
+                <Setter Property="VerticalContentAlignment" Value="Stretch"/>
+                <Setter Property="BorderBrush" Value="Transparent"/>
+                <Setter Property="BorderThickness" Value="1"/>
+                <Setter Property="Template">
+                    <Setter.Value>
+                        <ControlTemplate TargetType="{x:Type Expander}">
+                            <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="3" SnapsToDevicePixels="true">
+                                <DockPanel>
+                                    <ToggleButton x:Name="HeaderSite" ContentTemplate="{TemplateBinding HeaderTemplate}" ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}" Content="{TemplateBinding Header}" DockPanel.Dock="Top" Foreground="{TemplateBinding Foreground}" FontWeight="{TemplateBinding FontWeight}" FocusVisualStyle="{StaticResource ExpanderHeaderFocusVisual}" FontStyle="{TemplateBinding FontStyle}" FontStretch="{TemplateBinding FontStretch}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsChecked="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" MinWidth="0" MinHeight="0" Padding="{TemplateBinding Padding}" Style="{StaticResource ExpanderDownHeaderStyle}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
+                                    <ContentPresenter x:Name="ExpandSite" DockPanel.Dock="Bottom" Focusable="false" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" Visibility="Collapsed" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
+                                </DockPanel>
+                            </Border>
+                            <ControlTemplate.Triggers>
+                                <Trigger Property="IsExpanded" Value="true">
+                                    <Setter Property="Visibility" TargetName="ExpandSite" Value="Visible"/>
+                                </Trigger>
+                                <Trigger Property="IsEnabled" Value="false">
+                                    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
+                                </Trigger>
+                            </ControlTemplate.Triggers>
+                        </ControlTemplate>
+                    </Setter.Value>
+                </Setter>
+            </Style>
+        </DockPanel.Resources>
 
     <ui:FilterTextBox x:Name="filterText"
                       DockPanel.Dock="Top"
@@ -151,13 +212,15 @@
                 <Style TargetType="{x:Type GroupItem}">
                   <Setter Property="Template">
                     <Setter.Value>
-                      <ControlTemplate TargetType="{x:Type GroupItem}">
-                        <Expander IsExpanded="{Binding Name.IsExpanded}">
+                    <ControlTemplate TargetType="{x:Type GroupItem}">
+                        <Expander Style="{StaticResource StatusGroupExpander}" IsExpanded="{Binding Name.IsExpanded}">
                           <Expander.Header>
                             <Border Background="#F8F8F8"
+                                    Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Expander}}, Path=ActualWidth}"
                                     Style="{StaticResource repositoryBorderStyle}">
                             <StackPanel Orientation="Horizontal"
                                         VerticalAlignment="Center"
+                                        HorizontalAlignment="Stretch"
                                         Margin="0">
                                 <Image x:Name="avatar"
                                         Width="16"