From def057d5dac75b0b6c371ae11b7975e8db1c639a Mon Sep 17 00:00:00 2001
From: VladiStep <vlad2001.21@mail.ru>
Date: Fri, 17 Jun 2022 18:57:20 +0300
Subject: [PATCH 1/2] Any "UndertaleResource" can be opened in a new tab with
 MMB (in the asset list).

---
 UndertaleModTool/MainWindow.xaml    |  9 ++++++---
 UndertaleModTool/MainWindow.xaml.cs | 24 +++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/UndertaleModTool/MainWindow.xaml b/UndertaleModTool/MainWindow.xaml
index f81a1f37a..d5841a941 100644
--- a/UndertaleModTool/MainWindow.xaml
+++ b/UndertaleModTool/MainWindow.xaml
@@ -178,9 +178,12 @@
                     </Button>
                     <TextBox Grid.Column="1" Name="SearchBox" ToolTip="Search" TextChanged="SearchBox_TextChanged"/>
                 </Grid>
-                <TreeView Grid.Column="0" Grid.Row="1" Margin="5" DataContext="{Binding Data}" SelectedItemChanged="TreeView_SelectedItemChanged" MouseDoubleClick="MainTree_MouseDoubleClick" KeyUp="MainTree_KeyUp" AllowDrop="True" Name="MainTree" KeyDown="MainTree_KeyDown" PreviewMouseRightButtonDown="MainTree_PreviewMouseRightButtonDown"
-                    VirtualizingStackPanel.IsVirtualizing="True"
-                    VirtualizingStackPanel.VirtualizationMode="Recycling">
+                <TreeView Grid.Column="0" Grid.Row="1" Name="MainTree" Margin="5" DataContext="{Binding Data}" AllowDrop="True"
+                          SelectedItemChanged="TreeView_SelectedItemChanged"
+                          MouseDoubleClick="MainTree_MouseDoubleClick" PreviewMouseRightButtonDown="MainTree_PreviewMouseRightButtonDown" MouseDown="MainTree_MouseDown"
+                          KeyUp="MainTree_KeyUp" KeyDown="MainTree_KeyDown"
+                          VirtualizingStackPanel.IsVirtualizing="True"
+                          VirtualizingStackPanel.VirtualizationMode="Recycling">
                     <TreeView.Resources>
                         <ContextMenu x:Key="AddMenu">
                             <MenuItem Header="Add" Click="MenuItem_Add_Click"/>
diff --git a/UndertaleModTool/MainWindow.xaml.cs b/UndertaleModTool/MainWindow.xaml.cs
index fd810c783..41d60ffd1 100644
--- a/UndertaleModTool/MainWindow.xaml.cs
+++ b/UndertaleModTool/MainWindow.xaml.cs
@@ -1531,7 +1531,7 @@ private void TreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEv
         {
             if (e.NewValue is TreeViewItem)
             {
-                string item = (e.NewValue as TreeViewItem)?.Header?.ToString();
+                string item = (e.NewValue as TreeViewItem).Header?.ToString();
 
                 if (item == "Data")
                 {
@@ -1567,7 +1567,29 @@ private void MainTree_MouseDoubleClick(object sender, MouseButtonEventArgs e)
 
             OpenInTab(Highlighted);
         }
+        private void MainTree_MouseDown(object sender, MouseButtonEventArgs e)
+        {
+            if (e.ButtonState == MouseButtonState.Pressed && e.ChangedButton == System.Windows.Input.MouseButton.Middle)
+            {
+                DependencyObject obj = MainTree.InputHitTest(e.GetPosition(MainTree)) as DependencyObject;
+                if (obj is not TextBlock)
+                    return;
+
+                TreeViewItem item = GetNearestParent<TreeViewItem>(obj);
+                if (item is null)
+                    return;
+
+                item.IsSelected = true;
 
+                if (item.DataContext is not UndertaleResource)
+                    return;
+
+                if (Highlighted is UndertaleRoom room && Selected is not UndertaleRoom)
+                    UndertaleRoomEditor.CheckAndRearrangeLayers(room);
+
+                OpenInTab(Highlighted, true);
+            }
+        }
         private void MainTree_KeyUp(object sender, KeyEventArgs e)
         {
             if (e.Key == Key.Return)

From 586c9461428854959ce7b8f914dabccde9f70d11 Mon Sep 17 00:00:00 2001
From: VladiStep <vlad2001.21@mail.ru>
Date: Sat, 18 Jun 2022 15:10:38 +0300
Subject: [PATCH 2/2] Addressed @Miepee comment

---
 UndertaleModTool/MainWindow.xaml.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/UndertaleModTool/MainWindow.xaml.cs b/UndertaleModTool/MainWindow.xaml.cs
index 41d60ffd1..16e58e114 100644
--- a/UndertaleModTool/MainWindow.xaml.cs
+++ b/UndertaleModTool/MainWindow.xaml.cs
@@ -1571,6 +1571,9 @@ private void MainTree_MouseDown(object sender, MouseButtonEventArgs e)
         {
             if (e.ButtonState == MouseButtonState.Pressed && e.ChangedButton == System.Windows.Input.MouseButton.Middle)
             {
+                // Gets the clicked visual element by the mouse position (relative to "MainTree").
+                // This is used instead of "VisualTreeHelper.HitTest()" because that ignores the visibility of elements,
+                // which led to "ghost" hits on empty space.
                 DependencyObject obj = MainTree.InputHitTest(e.GetPosition(MainTree)) as DependencyObject;
                 if (obj is not TextBlock)
                     return;