From 621080096a4e8730e23afa482a28a0e5c436f21d Mon Sep 17 00:00:00 2001
From: Janos Bonic <86970079+janosdebugs@users.noreply.github.com>
Date: Mon, 15 Apr 2024 18:07:59 +0200
Subject: [PATCH] Fixes godotengine/godot-proposals#8850: Synchronously notify
 the scene tree of changes

---
 doc/classes/SceneTree.xml | 6 ++++++
 scene/main/node.cpp       | 2 ++
 scene/main/scene_tree.cpp | 5 +++++
 scene/main/scene_tree.h   | 2 ++
 4 files changed, 15 insertions(+)

diff --git a/doc/classes/SceneTree.xml b/doc/classes/SceneTree.xml
index bae5fe12054be..4d39618169221 100644
--- a/doc/classes/SceneTree.xml
+++ b/doc/classes/SceneTree.xml
@@ -278,6 +278,12 @@
 		</member>
 	</members>
 	<signals>
+		<signal name="node_adding">
+			<param index="0" name="node" type="Node" />
+			<description>
+				Emitted before the [param node] enters this tree.
+			</description>
+		</signal>
 		<signal name="node_added">
 			<param index="0" name="node" type="Node" />
 			<description>
diff --git a/scene/main/node.cpp b/scene/main/node.cpp
index 5c5049759f224..fd2e57edd3ad6 100644
--- a/scene/main/node.cpp
+++ b/scene/main/node.cpp
@@ -291,6 +291,8 @@ void Node::_propagate_enter_tree() {
 		E.value.group = data.tree->add_to_group(E.key, this);
 	}
 
+	data.tree->node_adding(this);
+
 	notification(NOTIFICATION_ENTER_TREE);
 
 	GDVIRTUAL_CALL(_enter_tree);
diff --git a/scene/main/scene_tree.cpp b/scene/main/scene_tree.cpp
index 04dd38fb5d2b2..fa7b795630cec 100644
--- a/scene/main/scene_tree.cpp
+++ b/scene/main/scene_tree.cpp
@@ -123,6 +123,10 @@ void SceneTree::tree_changed() {
 	emit_signal(tree_changed_name);
 }
 
+void SceneTree::node_adding(Node *p_node) {
+	emit_signal(node_adding_name, p_node);
+}
+
 void SceneTree::node_added(Node *p_node) {
 	emit_signal(node_added_name, p_node);
 }
@@ -1679,6 +1683,7 @@ void SceneTree::_bind_methods() {
 
 	ADD_SIGNAL(MethodInfo("tree_changed"));
 	ADD_SIGNAL(MethodInfo("tree_process_mode_changed")); //editor only signal, but due to API hash it can't be removed in run-time
+	ADD_SIGNAL(MethodInfo("node_adding", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
 	ADD_SIGNAL(MethodInfo("node_added", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
 	ADD_SIGNAL(MethodInfo("node_removed", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
 	ADD_SIGNAL(MethodInfo("node_renamed", PropertyInfo(Variant::OBJECT, "node", PROPERTY_HINT_RESOURCE_TYPE, "Node")));
diff --git a/scene/main/scene_tree.h b/scene/main/scene_tree.h
index c9f3a4de1f97d..0c5fd395eb9b6 100644
--- a/scene/main/scene_tree.h
+++ b/scene/main/scene_tree.h
@@ -140,6 +140,7 @@ class SceneTree : public MainLoop {
 	bool _physics_interpolation_enabled = false;
 
 	StringName tree_changed_name = "tree_changed";
+	StringName node_adding_name = "node_adding";
 	StringName node_added_name = "node_added";
 	StringName node_removed_name = "node_removed";
 	StringName node_renamed_name = "node_renamed";
@@ -204,6 +205,7 @@ class SceneTree : public MainLoop {
 	friend class Node;
 
 	void tree_changed();
+	void node_adding(Node *p_node);
 	void node_added(Node *p_node);
 	void node_removed(Node *p_node);
 	void node_renamed(Node *p_node);