statecharts ehehehehehe

addons/godot_state_charts/compound_state.gd

@@ -0,0 +1,104 @@
+tool
+class_name CompoundState, "compound_state.svg"
+extends State
+
+## initial state to activate when state is activated
+export var initial_state: NodePath setget _set_initial_state
+
+var _active_state: State = null
+
+onready var _initial_state: State = get_node_or_null(initial_state)
+
+func _set_initial_state(value: NodePath) -> void:
+	initial_state = value
+	update_configuration_warning()
+
+func _state_init() -> void:
+	._state_init()
+	
+	for child in get_children():
+		if child is State:
+			child._state_init()
+
+func _state_enter() -> void:
+	._state_enter()
+	
+	# activate initial state
+	if _initial_state != null:
+		_active_state = _initial_state
+		_active_state._state_enter()
+	else:
+		push_error("no initial state set for state %s" % name)
+
+func _state_exit() -> void:
+	# deactivate current state
+	if _active_state != null:
+		_active_state._state_exit()
+		_active_state = null
+	._state_exit()
+
+func _state_event(event: String) -> bool:
+	if not active:
+		return false
+	
+	# forward event to active state
+	if is_instance_valid(_active_state):
+		if _active_state._state_event(event):
+			emit_signal("event_received", event)
+			return true
+	
+	# if event not handled by active state, handle here
+	return ._state_event(event)
+
+func _handle_transition(transition: Transition, source: State) -> void:
+	var target: State = transition.resolve_target()
+	if not target is State:
+		push_error("the target state: %s of transition from state: %s is not a state" % [str(transition.to), source.name])
+		return
+	
+	# if direct child, just switch active state
+	if target in get_children():
+		# deactivate current state
+		if is_instance_valid(_active_state):
+			_active_state._state_exit()
+		# activate target state
+		_active_state = target
+		_active_state._state_enter()
+		return
+	
+	# if ancestor, activate next state down and let it handle transition further
+	if self.is_a_parent_of(target):
+		# find which child is also ancestor
+		for child in get_children():
+			if child.is_parent_of(target):
+				# change state if necessary
+				if _active_state != child:
+					if is_instance_valid(_active_state):
+						_active_state._state_exit()
+					_active_state = child
+					_active_state._state_enter()
+				child._handle_transition(transition, source)
+				return
+		return
+	
+	# target is a cousin, defer to mommy
+	get_parent()._handle_transition(transition, source)
+
+func _get_configuration_warning() -> String:
+	var warning := ._get_configuration_warning()
+	if not warning.empty():
+		return warning
+	
+	if get_child_count() == 0:
+		return "compound states must have at least one child state"
+	
+	var child_state = get_node_or_null(initial_state)
+	
+	if not is_instance_valid(child_state):
+		return "initial state not found, is the path correct?"
+	if child_state.get_parent() != self:
+		return "initial state must be a direct child of this compound state"
+	if not child_state is State:
+		return "initial state must be a State"
+	
+	return ""