Fixes #488 by adding resources to control content border of ribbon

You can now use Fluent.Ribbon.Values.RibbonTabControl.Content.BorderThickness to control the thickness of the border around the content area of RibbonTabControl

Changelog.md

@@ -185,6 +185,8 @@
   - [#480](../../issues/480) - Disable Scroll Wheel for tab selection  
   You can control this behavior by using `IsMouseWheelScrollingEnabled` on `Ribbon`
   - [#484](../../issues/484) - Add special style/template for MenuItem with set description
+  - [#488](../../issues/488) - Display border around content area of RibbonTabControl  
+  You can now use `Fluent.Ribbon.Values.RibbonTabControl.Content.BorderThickness` to control the thickness of the border around the content area of `RibbonTabControl`
 
 ## 5.0.2
   - [#437](../../issues/437) - "Could not load ControlzEx"

Fluent.Ribbon/Themes/Colors/BaseDark.xaml

@@ -107,6 +107,7 @@
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Background" Color="{StaticResource WhiteColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.Background" Color="#363636" options:Freeze="True" />
+    <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.BorderBrush" Color="Transparent" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.Foreground" Color="{StaticResource Gray6}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.TabsGrid.Background" Color="Transparent" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.TabsGrid.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />

Fluent.Ribbon/Themes/Colors/BaseLight.xaml

@@ -107,6 +107,7 @@
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Background" Color="{StaticResource WhiteColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.Background" Color="{StaticResource WhiteColor}" options:Freeze="True" />
+    <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.BorderBrush" Color="Transparent" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.TabsGrid.Background" Color="Transparent" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.TabsGrid.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />

Fluent.Ribbon/Themes/Colors/Colors.xaml

@@ -159,6 +159,7 @@
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Background" Color="{StaticResource WhiteColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.Background" Color="{StaticResource WhiteColor}" options:Freeze="True" />
+    <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.BorderBrush" Color="Transparent" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.Content.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.TabsGrid.Background" Color="Transparent" options:Freeze="True" />
     <SolidColorBrush x:Key="Fluent.Ribbon.Brushes.RibbonTabControl.TabsGrid.Foreground" Color="{StaticResource BlackColor}" options:Freeze="True" />

Fluent.Ribbon/Themes/Common.xaml

@@ -1,7 +1,10 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:Fluent="clr-namespace:Fluent">
-    <!-- Set default controls -->
+    <!-- Set default values -->
+    <Thickness x:Key="Fluent.Ribbon.Values.RibbonTabControl.Content.BorderThickness">0</Thickness>
+
+    <!-- Set default styles -->
     <Style TargetType="{x:Type Fluent:Spinner}" BasedOn="{StaticResource SpinnerStyle}" />
     <Style TargetType="{x:Type Fluent:TwoLineLabel}" BasedOn="{StaticResource TwoLineLabelStyle}" />
     <Style TargetType="{x:Type Fluent:KeyTip}" BasedOn="{StaticResource KeyTipStyle}" />

Fluent.Ribbon/Themes/Controls/Ribbon.xaml

@@ -17,7 +17,9 @@
                    TargetType="{x:Type ContextMenu}" />                        
         </ControlTemplate.Resources>
 
-        <Border Background="{TemplateBinding Background}">
+        <Border Background="{TemplateBinding Background}"
+                BorderThickness="{TemplateBinding BorderThickness}"
+                BorderBrush="{TemplateBinding BorderBrush}">
             <Grid x:Name="PART_LayoutRoot" 
                   Width="Auto"
                   Height="Auto">

Fluent.Ribbon/Themes/Controls/RibbonTabControl.xaml

@@ -233,6 +233,8 @@
                     Grid.Row="1"
                     Grid.RowSpan="1"
                     Background="{DynamicResource Fluent.Ribbon.Brushes.RibbonTabControl.Content.Background}"
+                    BorderBrush="{DynamicResource Fluent.Ribbon.Brushes.RibbonTabControl.Content.BorderBrush}"
+                    BorderThickness="{DynamicResource Fluent.Ribbon.Values.RibbonTabControl.Content.BorderThickness}"
                     TextElement.Foreground="{DynamicResource Fluent.Ribbon.Brushes.RibbonTabControl.Content.Foreground}"
                     KeyboardNavigation.TabNavigation="Local"
                     KeyboardNavigation.DirectionalNavigation="Contained"