add a few things:

* test case with folders/subfolders
* renaming items by double-clicking them
* naive drag test

ControlTree.gd

@@ -27,3 +27,12 @@ func add_item(text: String, parent_item: ControlTreeItem = null) -> ControlTreeI
 		new_item.set_button_group(item_select_btn_group)
 
 	return new_item
+
+
+func get_items_by_name(s: String) -> Array:
+	var res = []
+	for i in items:
+		if i.get_text() == s:
+			res.append(i)
+
+	return res

ControlTreeItem.gd

@@ -28,13 +28,20 @@ onready var item_text_button: Button = $"%ItemTextButton"
 
 onready var subitem_container: VBoxContainer = $"%Subitems"
 
+signal rename_allowed
+
 
 func _ready() -> void:
 # warning-ignore:return_value_discarded
+# warning-ignore:return_value_discarded
+# warning-ignore:return_value_discarded
 # warning-ignore:return_value_discarded
 	check_box.connect("pressed", self, "set_enabled", [true])
 	collapse_button.connect("pressed", self, "toggle_collapsed")
 
+	item_text_button.connect("rename_request", self, "rename_request")
+	connect("rename_allowed", item_text_button, "create_lineedit")
+
 
 func set_checked(v: bool, from_checkbox: bool = false) -> void:
 	checked = v
@@ -92,3 +99,15 @@ func toggle_collapsed() -> void:
 
 	for i in subitems:
 		i.visible = !collapsed
+
+
+func can_drop_data(_position: Vector2, data) -> bool:
+	if data is Control && data.has_method("i_am_item"):
+		return true
+
+	return false
+
+
+func rename_request() -> void:
+	if editable:
+		emit_signal("rename_allowed")

ControlTreeItem.tscn

@@ -1,6 +1,8 @@
-[gd_scene load_steps=2 format=2]
+[gd_scene load_steps=4 format=2]
 
 [ext_resource path="res://ControlTreeItem.gd" type="Script" id=1]
+[ext_resource path="res://DragHandle.gd" type="Script" id=2]
+[ext_resource path="res://RenamableButton.gd" type="Script" id=3]
 
 [node name="ControlTreeItem" type="VBoxContainer"]
 anchor_right = 0.479
@@ -39,6 +41,7 @@ unique_name_in_owner = true
 margin_right = 32.0
 margin_bottom = 32.0
 rect_min_size = Vector2( 32, 0 )
+script = ExtResource( 2 )
 
 [node name="CheckBox" type="CheckBox" parent="ItemAtom"]
 unique_name_in_owner = true
@@ -56,6 +59,7 @@ toggle_mode = true
 text = "Item text"
 flat = true
 align = 0
+script = ExtResource( 3 )
 
 [node name="Subitems" type="VBoxContainer" parent="."]
 unique_name_in_owner = true

DragHandle.gd

@@ -0,0 +1,5 @@
+extends Panel
+
+
+func get_drag_data(position: Vector2):
+	return get_parent().get_parent()

RenamableButton.gd

@@ -0,0 +1,42 @@
+extends Button
+
+var le: LineEdit = null
+
+signal rename_request
+
+
+func _gui_input(event: InputEvent) -> void:
+	if event is InputEventMouseButton && event.is_doubleclick() && !le:
+		emit_signal("rename_request")
+
+
+func remove_lineedit() -> void:
+	le.queue_free()
+	le = null
+
+
+func create_lineedit() -> void:
+	le = LineEdit.new()
+	get_tree().get_root().add_child(le)
+	le.rect_size = get_global_rect().size
+#	le.rect_size.x += 64 # some padding to make it more readable
+	le.rect_position = get_global_rect().position
+	le.expand_to_text_length = true
+	le.text = text
+	le.select_all()
+	le.grab_focus()
+	le.connect("text_entered", self, "lineeedit_text_entered")
+
+
+func lineeedit_text_entered(new_text: String) -> void:
+	le.queue_free()
+	le = null
+	text = new_text
+
+
+func _input(event: InputEvent) -> void:
+	if le && event is InputEventMouseButton && !(le.get_global_rect().has_point(event.position)):
+		remove_lineedit()
+
+	if event is InputEventKey && event.scancode == KEY_ESCAPE && le:
+		remove_lineedit()

TestArea.tscn

@@ -5,23 +5,60 @@
 [sub_resource type="GDScript" id=1]
 script/source = "extends Control
 
+onready var control_tree: ControlTree = $ControlTree
+
 var i
 var j
 
+var files: Array = [] # Array[FileDef]
+
 func _ready() -> void:
-	pass
+	files = get_dir_contents(ProjectSettings.globalize_path(\"res://test_dir\"))
+	construct_tree(files)
 
 
-func _on_Button_pressed() -> void:
-	i = $ControlTree.add_item('test')
+func get_dir_contents(path: String) -> Array:
+	var res = []
+	var dir = Directory.new()
+	if dir.open(path) == OK:
+		dir.list_dir_begin(true)
+		var fname = dir.get_next()
+		while fname != \"\":
+			var f = FileDef.new()
+			f.path = fname
+#			print(f.path)
+			if dir.current_is_dir():
+				var a = get_dir_contents(path.plus_file(fname))
+				f.contains.append_array(a)
+
+			res.append(f)
+			fname = dir.get_next()
+		dir.list_dir_end()
+	return res
 
 
-func _on_Button2_pressed() -> void:
-	j = $ControlTree.add_item('test2', i)
+func construct_tree(from: Array, parent: ControlTreeItem = null):
+	for f in from:
+		var item = control_tree.add_item(f.path, parent)
+		if f.contains:
+			item.editable = false
+			construct_tree(f.contains, item)
 
 
-func _on_Button3_pressed() -> void:
-	$ControlTree.add_item('test3', j)
+#func _on_Button_pressed() -> void:
+#	i = $ControlTree.add_item('test')
+#
+#
+#func _on_Button2_pressed() -> void:
+#	j = $ControlTree.add_item('test2', i)
+#
+#
+#func _on_Button3_pressed() -> void:
+#	$ControlTree.add_item('test3', j)
+
+class FileDef:
+	var path: String
+	var contains: Array # Array[FileDef]
 "
 
 [node name="TestArea" type="Control"]

project.godot

@@ -27,6 +27,7 @@ _global_script_class_icons={
 [application]
 
 config/name="customtree"
+run/main_scene="res://TestArea.tscn"
 config/icon="res://icon.png"
 
 [gui]

test_dir/file in root 1.txt

@@ -0,0 +1 @@
+ 

test_dir/file in root 2.txt

@@ -0,0 +1 @@
+ 

test_dir/folder1/file in folder.txt

@@ -0,0 +1 @@
+ 

test_dir/folder1/subfolder/file in subfolder.txt

@@ -0,0 +1 @@
+