From 5e2c641f02f0c6d4382ed1a040c86c5576d825ca Mon Sep 17 00:00:00 2001
From: Maksym Katsydan <maxkatz6@outlook.com>
Date: Tue, 21 Jul 2020 20:21:13 -0400
Subject: [PATCH] Move Popup in Fluent MenuItem to another parent node and add
 MenuFlyoutSubItemPopupHorizontalOffset

---
 src/Avalonia.Themes.Fluent/MenuItem.xaml | 155 ++++++++++++-----------
 1 file changed, 79 insertions(+), 76 deletions(-)

diff --git a/src/Avalonia.Themes.Fluent/MenuItem.xaml b/src/Avalonia.Themes.Fluent/MenuItem.xaml
index 4899bf264f..0442c38025 100644
--- a/src/Avalonia.Themes.Fluent/MenuItem.xaml
+++ b/src/Avalonia.Themes.Fluent/MenuItem.xaml
@@ -40,6 +40,7 @@
 
   <Styles.Resources>
     <conv:PlatformKeyGestureConverter x:Key="KeyGestureConverter" />
+    <x:Double x:Key="MenuFlyoutSubItemPopupHorizontalOffset">-4</x:Double>
     <Thickness x:Key="MenuFlyoutScrollerMargin">0,4,0,4</Thickness>
     <Thickness x:Key="MenuIconPresenterMargin">0,0,12,0</Thickness>
     <Thickness x:Key="MenuInputGestureTextMargin">24,0,0,0</Thickness>    
@@ -54,83 +55,85 @@
     <Setter Property="FontSize" Value="{DynamicResource ControlContentThemeFontSize}" />
     <Setter Property="Template">
       <ControlTemplate>
-        <Border Name="PART_LayoutRoot"
-                Padding="{TemplateBinding Padding}"
-                Background="{TemplateBinding Background}"
-                BorderBrush="{TemplateBinding BorderBrush}"
-                BorderThickness="{TemplateBinding BorderThickness}">
-          <Grid>
-            <Grid.ColumnDefinitions>
-              <ColumnDefinition Width="Auto"
-                                SharedSizeGroup="MenuItemIcon"  />
-              <ColumnDefinition Width="*" />
-              <ColumnDefinition Width="Auto"
-                                SharedSizeGroup="MenuItemIGT" />
-              <ColumnDefinition Width="Auto"
-                                SharedSizeGroup="MenuItemChevron" />
-            </Grid.ColumnDefinitions>
-            <ContentPresenter Name="PART_IconPresenter"
-                              Content="{TemplateBinding Icon}"
-                              Width="16"
-                              Height="16"
-                              Margin="{DynamicResource MenuIconPresenterMargin}"
-                              HorizontalAlignment="Center"
-                              VerticalAlignment="Center"/>
+        <Panel>
+          <Border Name="PART_LayoutRoot"
+                  Padding="{TemplateBinding Padding}"
+                  Background="{TemplateBinding Background}"
+                  BorderBrush="{TemplateBinding BorderBrush}"
+                  BorderThickness="{TemplateBinding BorderThickness}">
+            <Grid>
+              <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="Auto"
+                                  SharedSizeGroup="MenuItemIcon" />
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="Auto"
+                                  SharedSizeGroup="MenuItemIGT" />
+                <ColumnDefinition Width="Auto"
+                                  SharedSizeGroup="MenuItemChevron" />
+              </Grid.ColumnDefinitions>
+              <ContentPresenter Name="PART_IconPresenter"
+                                Content="{TemplateBinding Icon}"
+                                Width="16"
+                                Height="16"
+                                Margin="{DynamicResource MenuIconPresenterMargin}"
+                                HorizontalAlignment="Center"
+                                VerticalAlignment="Center" />
 
-            <ContentPresenter Name="PART_HeaderPresenter"
-                              Content="{TemplateBinding Header}"
-                              VerticalAlignment="Center"
-                              HorizontalAlignment="Stretch"
-                              TextBlock.Foreground="{TemplateBinding Foreground}"
-                              Grid.Column="1">
-              <ContentPresenter.DataTemplates>
-                <DataTemplate DataType="sys:String">
-                  <AccessText Text="{Binding}" />
-                </DataTemplate>
-              </ContentPresenter.DataTemplates>
-            </ContentPresenter>
-            <TextBlock x:Name="PART_InputGestureText"
-                       Grid.Column="2"
-                       Classes="CaptionTextBlockStyle"
-                       Margin="{DynamicResource MenuInputGestureTextMargin}"
-                       Text="{TemplateBinding InputGesture,
-                                              Converter={StaticResource KeyGestureConverter}}"
-                       HorizontalAlignment="Right"
-                       VerticalAlignment="Center" />
-            <Path Name="PART_ChevronPath"
-                  Stretch="Uniform"
-                  Width="8"
-                  Height="16"
-                  Data="{StaticResource MenuItemChevronPathData}"
-                  Margin="{DynamicResource MenuFlyoutItemChevronMargin}"
-                  VerticalAlignment="Center"
-                  Grid.Column="3" />
-            <Popup Name="PART_Popup"
-                   WindowManagerAddShadowHint="True"
-                   PlacementMode="Right"
-                   StaysOpen="True"
-                   IsOpen="{TemplateBinding IsSubMenuOpen,
-                                            Mode=TwoWay}">
-              <Border Background="{DynamicResource MenuFlyoutPresenterBackground}"
-                      BorderBrush="{DynamicResource MenuFlyoutPresenterBorderBrush}"
-                      BorderThickness="{DynamicResource MenuFlyoutPresenterBorderThemeThickness}"
-                      Padding="{DynamicResource MenuFlyoutPresenterThemePadding}"
-                      MaxWidth="{DynamicResource FlyoutThemeMaxWidth}"
-                      MinHeight="{DynamicResource MenuFlyoutThemeMinHeight}"
-                      HorizontalAlignment="Stretch"
-                      CornerRadius="{DynamicResource OverlayCornerRadius}">
-                <ScrollViewer>
-                  <ItemsPresenter Name="PART_ItemsPresenter"
-                                  Items="{TemplateBinding Items}"
-                                  ItemsPanel="{TemplateBinding ItemsPanel}"
-                                  ItemTemplate="{TemplateBinding ItemTemplate}"
-                                  Margin="{DynamicResource MenuFlyoutScrollerMargin}"
-                                  Grid.IsSharedSizeScope="True" />
-                </ScrollViewer>
-              </Border>
-            </Popup>
-          </Grid>
-        </Border>
+              <ContentPresenter Name="PART_HeaderPresenter"
+                                Content="{TemplateBinding Header}"
+                                VerticalAlignment="Center"
+                                HorizontalAlignment="Stretch"
+                                TextBlock.Foreground="{TemplateBinding Foreground}"
+                                Grid.Column="1">
+                <ContentPresenter.DataTemplates>
+                  <DataTemplate DataType="sys:String">
+                    <AccessText Text="{Binding}" />
+                  </DataTemplate>
+                </ContentPresenter.DataTemplates>
+              </ContentPresenter>
+              <TextBlock x:Name="PART_InputGestureText"
+                         Grid.Column="2"
+                         Classes="CaptionTextBlockStyle"
+                         Margin="{DynamicResource MenuInputGestureTextMargin}"
+                         Text="{TemplateBinding InputGesture, Converter={StaticResource KeyGestureConverter}}"
+                         HorizontalAlignment="Right"
+                         VerticalAlignment="Center" />
+              <Path Name="PART_ChevronPath"
+                    Stretch="Uniform"
+                    Width="8"
+                    Height="16"
+                    Data="{StaticResource MenuItemChevronPathData}"
+                    Margin="{DynamicResource MenuFlyoutItemChevronMargin}"
+                    VerticalAlignment="Center"
+                    Grid.Column="3" />
+            </Grid>
+          </Border>
+          <Popup Name="PART_Popup"
+                 WindowManagerAddShadowHint="True"
+                 PlacementMode="Right"
+                 HorizontalOffset="{StaticResource MenuFlyoutSubItemPopupHorizontalOffset}"
+                 StaysOpen="True"
+                 IsOpen="{TemplateBinding IsSubMenuOpen,
+                                          Mode=TwoWay}">
+            <Border Background="{DynamicResource MenuFlyoutPresenterBackground}"
+                    BorderBrush="{DynamicResource MenuFlyoutPresenterBorderBrush}"
+                    BorderThickness="{DynamicResource MenuFlyoutPresenterBorderThemeThickness}"
+                    Padding="{DynamicResource MenuFlyoutPresenterThemePadding}"
+                    MaxWidth="{DynamicResource FlyoutThemeMaxWidth}"
+                    MinHeight="{DynamicResource MenuFlyoutThemeMinHeight}"
+                    HorizontalAlignment="Stretch"
+                    CornerRadius="{DynamicResource OverlayCornerRadius}">
+              <ScrollViewer>
+                <ItemsPresenter Name="PART_ItemsPresenter"
+                                Items="{TemplateBinding Items}"
+                                ItemsPanel="{TemplateBinding ItemsPanel}"
+                                ItemTemplate="{TemplateBinding ItemTemplate}"
+                                Margin="{DynamicResource MenuFlyoutScrollerMargin}"
+                                Grid.IsSharedSizeScope="True" />
+              </ScrollViewer>
+            </Border>
+          </Popup>
+        </Panel>
       </ControlTemplate>
     </Setter>
   </Style>