Fixing TabControl TabItem lightweight styling options

src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/TabControl.xaml

@@ -5,7 +5,9 @@
     All Rights Reserved.
 -->
 
-<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:sys="clr-namespace:System;assembly=mscorlib">
 
     <!-- Styles when TabItems are on the Top -->
     <ControlTemplate x:Key="DefaultTopTabControlStyle" TargetType="{x:Type TabControl}">
@@ -207,6 +209,11 @@
             </Style.Triggers>
     </Style>
 
+    <sys:Double x:Key="TabItemHeaderMinHeight">32</sys:Double>
+    <sys:Double x:Key="TabItemHeaderMinWidth">100</sys:Double>
+    <sys:Double x:Key="TabItemHeaderFontSize">14</sys:Double>
+    <Thickness x:Key="TabItemHeaderPadding">8,6,8,6</Thickness>
+
     <Style TargetType="{x:Type TabItem}">
         <Setter Property="Background" Value="{DynamicResource TabViewItemHeaderBackground}" />
         <Setter Property="BorderBrush" Value="Transparent" />
@@ -225,10 +232,10 @@
                     <Grid x:Name="Root">
                         <Border
                             x:Name="Border"
-                            MinWidth="180"
-                            MinHeight="36"
+                            MinWidth="{DynamicResource TabItemHeaderMinWidth}"
+                            MinHeight="{DynamicResource TabItemHeaderMinHeight}"
                             Margin="0"
-                            Padding="6"
+                            Padding="{DynamicResource TabItemHeaderPadding}"
                             Background="{TemplateBinding Background}"
                             BorderBrush="{TemplateBinding BorderBrush}"
                             BorderThickness="1,1,1,0"
@@ -238,6 +245,7 @@
                                 HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                                 VerticalAlignment="{TemplateBinding VerticalContentAlignment}" 
                                 ContentSource="Header"
+                                TextElement.FontSize="{DynamicResource TabItemHeaderFontSize}"
                                 SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" 
                                 Margin="{TemplateBinding Padding}"
                                 RecognizesAccessKey="True" />

src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml

@@ -4047,6 +4047,10 @@
       </Trigger>
     </Style.Triggers>
   </Style>
+  <sys:Double x:Key="TabItemHeaderMinHeight">32</sys:Double>
+  <sys:Double x:Key="TabItemHeaderMinWidth">100</sys:Double>
+  <sys:Double x:Key="TabItemHeaderFontSize">14</sys:Double>
+  <Thickness x:Key="TabItemHeaderPadding">8,6,8,6</Thickness>
   <Style TargetType="{x:Type TabItem}">
     <Setter Property="Background" Value="{DynamicResource TabViewItemHeaderBackground}" />
     <Setter Property="BorderBrush" Value="Transparent" />
@@ -4063,8 +4067,8 @@
       <Setter.Value>
         <ControlTemplate TargetType="{x:Type TabItem}">
           <Grid x:Name="Root">
-            <Border x:Name="Border" MinWidth="180" MinHeight="36" Margin="0" Padding="6" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="8,8,0,0">
-              <ContentPresenter x:Name="ContentSite" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" ContentSource="Header" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" />
+            <Border x:Name="Border" MinWidth="{DynamicResource TabItemHeaderMinWidth}" MinHeight="{DynamicResource TabItemHeaderMinHeight}" Margin="0" Padding="{DynamicResource TabItemHeaderPadding}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="8,8,0,0">
+              <ContentPresenter x:Name="ContentSite" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" ContentSource="Header" TextElement.FontSize="{DynamicResource TabItemHeaderFontSize}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" />
             </Border>
             <VisualStateManager.VisualStateGroups>
               <VisualStateGroup x:Name="SelectionStates">

src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml

@@ -4008,6 +4008,10 @@
       </Trigger>
     </Style.Triggers>
   </Style>
+  <sys:Double x:Key="TabItemHeaderMinHeight">32</sys:Double>
+  <sys:Double x:Key="TabItemHeaderMinWidth">100</sys:Double>
+  <sys:Double x:Key="TabItemHeaderFontSize">14</sys:Double>
+  <Thickness x:Key="TabItemHeaderPadding">8,6,8,6</Thickness>
   <Style TargetType="{x:Type TabItem}">
     <Setter Property="Background" Value="{DynamicResource TabViewItemHeaderBackground}" />
     <Setter Property="BorderBrush" Value="Transparent" />
@@ -4024,8 +4028,8 @@
       <Setter.Value>
         <ControlTemplate TargetType="{x:Type TabItem}">
           <Grid x:Name="Root">
-            <Border x:Name="Border" MinWidth="180" MinHeight="36" Margin="0" Padding="6" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="8,8,0,0">
-              <ContentPresenter x:Name="ContentSite" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" ContentSource="Header" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" />
+            <Border x:Name="Border" MinWidth="{DynamicResource TabItemHeaderMinWidth}" MinHeight="{DynamicResource TabItemHeaderMinHeight}" Margin="0" Padding="{DynamicResource TabItemHeaderPadding}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="8,8,0,0">
+              <ContentPresenter x:Name="ContentSite" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" ContentSource="Header" TextElement.FontSize="{DynamicResource TabItemHeaderFontSize}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" />
             </Border>
             <VisualStateManager.VisualStateGroups>
               <VisualStateGroup x:Name="SelectionStates">

src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml

@@ -4048,6 +4048,10 @@
       </Trigger>
     </Style.Triggers>
   </Style>
+  <sys:Double x:Key="TabItemHeaderMinHeight">32</sys:Double>
+  <sys:Double x:Key="TabItemHeaderMinWidth">100</sys:Double>
+  <sys:Double x:Key="TabItemHeaderFontSize">14</sys:Double>
+  <Thickness x:Key="TabItemHeaderPadding">8,6,8,6</Thickness>
   <Style TargetType="{x:Type TabItem}">
     <Setter Property="Background" Value="{DynamicResource TabViewItemHeaderBackground}" />
     <Setter Property="BorderBrush" Value="Transparent" />
@@ -4064,8 +4068,8 @@
       <Setter.Value>
         <ControlTemplate TargetType="{x:Type TabItem}">
           <Grid x:Name="Root">
-            <Border x:Name="Border" MinWidth="180" MinHeight="36" Margin="0" Padding="6" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="8,8,0,0">
-              <ContentPresenter x:Name="ContentSite" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" ContentSource="Header" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" />
+            <Border x:Name="Border" MinWidth="{DynamicResource TabItemHeaderMinWidth}" MinHeight="{DynamicResource TabItemHeaderMinHeight}" Margin="0" Padding="{DynamicResource TabItemHeaderPadding}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="1,1,1,0" CornerRadius="8,8,0,0">
+              <ContentPresenter x:Name="ContentSite" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" ContentSource="Header" TextElement.FontSize="{DynamicResource TabItemHeaderFontSize}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" />
             </Border>
             <VisualStateManager.VisualStateGroups>
               <VisualStateGroup x:Name="SelectionStates">