From 79c4c74973f710f5ee0629821a455fea6dcdadf8 Mon Sep 17 00:00:00 2001
From: Nice3point <nice3point@gmail.com>
Date: Sat, 10 Dec 2022 00:05:15 +0300
Subject: [PATCH] TreeViewItem virtualizing support

---
 src/Wpf.Ui/Styles/Controls/TreeViewItem.xaml | 22 ++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/Wpf.Ui/Styles/Controls/TreeViewItem.xaml b/src/Wpf.Ui/Styles/Controls/TreeViewItem.xaml
index 837dfd382..a17d3e6d1 100644
--- a/src/Wpf.Ui/Styles/Controls/TreeViewItem.xaml
+++ b/src/Wpf.Ui/Styles/Controls/TreeViewItem.xaml
@@ -187,6 +187,17 @@
                 </ControlTemplate>
             </Setter.Value>
         </Setter>
+        <Style.Triggers>
+            <Trigger Property="VirtualizingPanel.IsVirtualizing" Value="True">
+                <Setter Property="ItemsPanel">
+                    <Setter.Value>
+                        <ItemsPanelTemplate>
+                            <VirtualizingStackPanel/>
+                        </ItemsPanelTemplate>
+                    </Setter.Value>
+                </Setter>
+            </Trigger>
+        </Style.Triggers>
     </Style>
 
     <Style x:Key="DefaultUiTreeViewItemStyle" TargetType="{x:Type controls:TreeViewItem}">
@@ -345,6 +356,17 @@
                 </ControlTemplate>
             </Setter.Value>
         </Setter>
+        <Style.Triggers>
+            <Trigger Property="VirtualizingPanel.IsVirtualizing" Value="True">
+                <Setter Property="ItemsPanel">
+                    <Setter.Value>
+                        <ItemsPanelTemplate>
+                            <VirtualizingStackPanel/>
+                        </ItemsPanelTemplate>
+                    </Setter.Value>
+                </Setter>
+            </Trigger>
+        </Style.Triggers>
     </Style>
 
     <Style BasedOn="{StaticResource DefaultTreeViewItemStyle}" TargetType="{x:Type TreeViewItem}" />