BTSubtree: Fix subtree blackboard plan is not property utilized

bt/tasks/decorators/bt_new_scope.cpp

@@ -11,6 +11,15 @@
 
 #include "bt_new_scope.h"
 
+void BTNewScope::set_blackboard_plan(const Ref<BlackboardPlan> &p_plan) {
+	blackboard_plan = p_plan;
+	if (blackboard_plan.is_null()) {
+		blackboard_plan.instantiate();
+	}
+	_update_blackboard_plan();
+	emit_changed();
+}
+
 void BTNewScope::initialize(Node *p_agent, const Ref<Blackboard> &p_blackboard) {
 	ERR_FAIL_COND(p_agent == nullptr);
 	ERR_FAIL_COND(p_blackboard == nullptr);

bt/tasks/decorators/bt_new_scope.h

@@ -26,7 +26,9 @@ private:
 protected:
 	static void _bind_methods();
 
-	void set_blackboard_plan(const Ref<BlackboardPlan> &p_plan) { blackboard_plan = p_plan; }
+	virtual void _update_blackboard_plan() {}
+
+	void set_blackboard_plan(const Ref<BlackboardPlan> &p_plan);
 	Ref<BlackboardPlan> get_blackboard_plan() const { return blackboard_plan; }
 
 	virtual Status _tick(double p_delta) override;

bt/tasks/decorators/bt_subtree.cpp

@@ -11,11 +11,27 @@
 
 #include "bt_subtree.h"
 
-void BTSubtree::set_subtree(const Ref<BehaviorTree> &p_value) {
+void BTSubtree::set_subtree(const Ref<BehaviorTree> &p_subtree) {
-	subtree = p_value;
+	if (Engine::get_singleton()->is_editor_hint()) {
+		if (subtree.is_valid() && subtree->is_connected(LW_NAME(changed), callable_mp(this, &BTSubtree::_update_blackboard_plan))) {
+			subtree->disconnect(LW_NAME(changed), callable_mp(this, &BTSubtree::_update_blackboard_plan));
+		}
+		if (p_subtree.is_valid()) {
+			p_subtree->connect(LW_NAME(changed), callable_mp(this, &BTSubtree::_update_blackboard_plan));
+		}
+	}
+	subtree = p_subtree;
+	_update_blackboard_plan();
 	emit_changed();
 }
 
+void BTSubtree::_update_blackboard_plan() {
+	if (get_blackboard_plan().is_null()) {
+		set_blackboard_plan(Ref<BlackboardPlan>(memnew(BlackboardPlan)));
+	}
+	get_blackboard_plan()->set_base_plan(subtree.is_valid() ? subtree->get_blackboard_plan() : nullptr);
+}
+
 String BTSubtree::_generate_name() {
 	String s;
 	if (subtree.is_null()) {
@@ -57,3 +73,11 @@ void BTSubtree::_bind_methods() {
 
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "subtree", PROPERTY_HINT_RESOURCE_TYPE, "BehaviorTree"), "set_subtree", "get_subtree");
 }
+
+BTSubtree::~BTSubtree() {
+	if (Engine::get_singleton()->is_editor_hint()) {
+		if (subtree.is_valid() && subtree->is_connected(LW_NAME(changed), callable_mp(this, &BTSubtree::_update_blackboard_plan))) {
+			subtree->disconnect(LW_NAME(changed), callable_mp(this, &BTSubtree::_update_blackboard_plan));
+		}
+	}
+}

bt/tasks/decorators/bt_subtree.h

@@ -26,6 +26,8 @@ private:
 protected:
 	static void _bind_methods();
 
+	virtual void _update_blackboard_plan() override;
+
 	virtual String _generate_name() override;
 	virtual Status _tick(double p_delta) override;
 
@@ -35,6 +37,9 @@ public:
 
 	virtual void initialize(Node *p_agent, const Ref<Blackboard> &p_blackboard) override;
 	virtual PackedStringArray get_configuration_warnings() override;
+
+	BTSubtree() = default;
+	~BTSubtree();
 };
 
 #endif // BT_SUBTREE_H