Merge branch 'add-root-tree-line-option' of https://github.com/Tryibion/FlaxEngine into Tryibion-add-root-tree-line-option

Source/Editor/GUI/Tree/Tree.cs

@@ -67,6 +67,11 @@ namespace FlaxEditor.GUI.Tree
         /// Gets the first selected node or null.
         /// </summary>
         public TreeNode SelectedNode => Selection.Count > 0 ? Selection[0] : null;
+        
+        /// <summary>
+        /// Allow nodes to Draw the root tree line.
+        /// </summary>
+        public bool DrawRootTreeLine = true;
 
         /// <summary>
         /// Gets or sets the margin for the child tree nodes.

Source/Editor/GUI/Tree/TreeNode.cs

@@ -762,7 +762,7 @@ namespace FlaxEditor.GUI.Tree
             {
                 TreeNode parentNode = Parent as TreeNode;
                 bool thisNodeIsLast = false;
-                while (parentNode != null && parentNode != ParentTree.Children[0])
+                while (parentNode != null && (parentNode != ParentTree.Children[0] || _tree.DrawRootTreeLine))
                 {
                     float bottomOffset = 0;
                     float topOffset = 0;
@@ -773,7 +773,7 @@ namespace FlaxEditor.GUI.Tree
                     if (thisNodeIsLast && parentNode.Children.Count == 1)
                         bottomOffset = topOffset != 0 ? 4 : 2;
 
-                    if (Parent == parentNode && this == Parent.Children[Parent.Children.Count - 1] && !_opened)
+                    if (Parent == parentNode && this == Parent.Children[^1] && !_opened)
                     {
                         thisNodeIsLast = true;
                         bottomOffset = topOffset != 0 ? 4 : 2;

Source/Editor/Windows/Assets/PrefabWindow.Hierarchy.cs

@@ -56,6 +56,7 @@ namespace FlaxEditor.Windows.Assets
             public PrefabTree()
             : base(true)
             {
+                DrawRootTreeLine = false;
             }
         }
 

Source/Editor/Windows/SceneTreeWindow.cs

@@ -85,6 +85,7 @@ namespace FlaxEditor.Windows
             {
                 Margin = new Margin(0.0f, 0.0f, -16.0f, _sceneTreePanel.ScrollBarsSize), // Hide root node
                 IsScrollable = true,
+                DrawRootTreeLine = false,
             };
             _tree.AddChild(root.TreeNode);
             _tree.SelectedChanged += Tree_OnSelectedChanged;