From 422926cfc641f895a84c9767aa418c22bf0f06ef Mon Sep 17 00:00:00 2001
From: Andrea Catania <info@andreacatania.com>
Date: Mon, 16 Mar 2020 17:42:29 +0100
Subject: [PATCH] Added new method to replace an already added node to the
 animation state machine

---
 doc/classes/AnimationNodeStateMachine.xml     | 11 ++++++++++
 .../animation_node_state_machine.cpp          | 22 +++++++++++++++++++
 .../animation/animation_node_state_machine.h  |  1 +
 3 files changed, 34 insertions(+)

diff --git a/doc/classes/AnimationNodeStateMachine.xml b/doc/classes/AnimationNodeStateMachine.xml
index 39a9af5ead2..04cf7489c07 100644
--- a/doc/classes/AnimationNodeStateMachine.xml
+++ b/doc/classes/AnimationNodeStateMachine.xml
@@ -28,6 +28,17 @@
 				Adds a new node to the graph. The [code]position[/code] is used for display in the editor.
 			</description>
 		</method>
+		<method name="replace_node">
+			<return type="void">
+			</return>
+			<argument index="0" name="name" type="String">
+			</argument>
+			<argument index="1" name="node" type="AnimationNode">
+			</argument>
+			<description>
+				Replaces the node and keeps its transitions unchanged.
+			</description>
+		</method>
 		<method name="add_transition">
 			<return type="void">
 			</return>
diff --git a/scene/animation/animation_node_state_machine.cpp b/scene/animation/animation_node_state_machine.cpp
index 665060d8992..95e34477424 100644
--- a/scene/animation/animation_node_state_machine.cpp
+++ b/scene/animation/animation_node_state_machine.cpp
@@ -565,6 +565,27 @@ void AnimationNodeStateMachine::add_node(const StringName &p_name, Ref<Animation
 	p_node->connect_compat("tree_changed", this, "_tree_changed", varray(), CONNECT_REFERENCE_COUNTED);
 }
 
+void AnimationNodeStateMachine::replace_node(const StringName &p_name, Ref<AnimationNode> p_node) {
+
+	ERR_FAIL_COND(states.has(p_name) == false);
+	ERR_FAIL_COND(p_node.is_null());
+	ERR_FAIL_COND(String(p_name).find("/") != -1);
+
+	{
+		Ref<AnimationNode> node = states[p_name].node;
+		if (node.is_valid()) {
+			node->disconnect_compat("tree_changed", this, "_tree_changed");
+		}
+	}
+
+	states[p_name].node = p_node;
+
+	emit_changed();
+	emit_signal("tree_changed");
+
+	p_node->connect_compat("tree_changed", this, "_tree_changed", varray(), CONNECT_REFERENCE_COUNTED);
+}
+
 Ref<AnimationNode> AnimationNodeStateMachine::get_node(const StringName &p_name) const {
 
 	ERR_FAIL_COND_V(!states.has(p_name), Ref<AnimationNode>());
@@ -949,6 +970,7 @@ void AnimationNodeStateMachine::_tree_changed() {
 void AnimationNodeStateMachine::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("add_node", "name", "node", "position"), &AnimationNodeStateMachine::add_node, DEFVAL(Vector2()));
+	ClassDB::bind_method(D_METHOD("replace_node", "name", "node"), &AnimationNodeStateMachine::replace_node);
 	ClassDB::bind_method(D_METHOD("get_node", "name"), &AnimationNodeStateMachine::get_node);
 	ClassDB::bind_method(D_METHOD("remove_node", "name"), &AnimationNodeStateMachine::remove_node);
 	ClassDB::bind_method(D_METHOD("rename_node", "name", "new_name"), &AnimationNodeStateMachine::rename_node);
diff --git a/scene/animation/animation_node_state_machine.h b/scene/animation/animation_node_state_machine.h
index 55c9c3f00e2..27a4451f082 100644
--- a/scene/animation/animation_node_state_machine.h
+++ b/scene/animation/animation_node_state_machine.h
@@ -178,6 +178,7 @@ public:
 	virtual Variant get_parameter_default_value(const StringName &p_parameter) const;
 
 	void add_node(const StringName &p_name, Ref<AnimationNode> p_node, const Vector2 &p_position = Vector2());
+	void replace_node(const StringName &p_name, Ref<AnimationNode> p_node);
 	Ref<AnimationNode> get_node(const StringName &p_name) const;
 	void remove_node(const StringName &p_name);
 	void rename_node(const StringName &p_name, const StringName &p_new_name);