Add state_holder

behaviours/draggable.gd

@@ -6,29 +6,38 @@ signal move(movement: Vector2)
 signal dragged
 signal dropped
 
+@export var state_holder: StateHolder
 
 @onready var mover: Node2D = $"MatchMousePosition"
 
-var being_dragged: bool:
+var is_being_dragged: bool:
 	get:
-		return being_dragged
-	set(value):
-		being_dragged = value
-		mover.set_process(being_dragged)
-		mover.set_physics_process(being_dragged)
+		return state_holder.state == 'dragged'
 
 
 func drag():
-	being_dragged = true
+	if not state_holder.propose_state('dragged', 100, _on_dropped):
+		return false
+	
+	_update_mover_process()
 	dragged.emit()
 
 func drop():
-	being_dragged = false
+	state_holder.remove_state('dragged')
+
+func _on_dropped():
 	dropped.emit()
 
+func _update_mover_process():
+	var value = is_being_dragged
+	mover.set_process(value)
+	mover.set_physics_process(value)
 
 func _ready():
-	being_dragged = false
+	if state_holder == null:
+		state_holder = StateHolder.get_default(self)
+	_update_mover_process()
 
 func _on_move(movement: Vector2):
-	move.emit(movement)
+	if is_being_dragged:
+		move.emit(movement)

behaviours/eat_target.gd

@@ -16,19 +16,24 @@ signal move(movement: Vector2)
 			eater.tag = value
 
 
+@export var state_holder: StateHolder
+
 @onready var hunt_target: HuntTarget = $"HuntTarget"
 @onready var eater: Eater = $"Eater"
 @onready var move_towards: MoveTowardsTarget = $"MoveTowardsTarget"
 
 func _ready():
+	if state_holder == null:
+		state_holder = StateHolder.get_default(self)
 	hunt_target.tag = tag
 	eater.tag = tag
 
 func _on_target_selected(body: Node2D) -> void:
-	move_towards.target = body
+	if state_holder.propose_state('hunt', 60, func(): move_towards.target = null):
+		move_towards.target = body
 
 func _on_target_abandoned(_body: Node2D) -> void:
-	move_towards.target = null
+	state_holder.remove_state('hunt')
 
 func _on_eater_eaten(edible):
 	eaten.emit(edible)

behaviours/move_towards_mouse.gd

@@ -11,10 +11,13 @@ signal captured
 @export var speed: float = 100.0
 @export var can_detach: bool = false
 
+@export var state_holder: StateHolder
+@export var state_name: StringName = ''
 
-enum State { DETACHED, CAPTURED }
 
-var state: State = State.DETACHED
+var is_captured: bool :
+	get: 
+		return state_holder.state == state_name
 
 func get_followed_global_position():
 	return game.camera.get_global_mouse_position()
@@ -26,21 +29,27 @@ func get_followed_mouse_position():
 	return relative_followed_position
 
 
+func _ready():
+	if state_holder == null:
+		if state_name == '':
+			state_holder = StateHolder.new()
+		else:
+			state_holder = StateHolder.get_default(self)
+
 func _physics_process(delta: float) -> void:
-	match state:
-		State.CAPTURED:
-			var relative_followed_position: Vector2 = get_followed_mouse_position()
-			var direction: Vector2 = position.direction_to(relative_followed_position)
-			var actual_speed: float = min(delta * speed, relative_followed_position.length())  # Don't overshoot.
-			var movement: Vector2 = direction * actual_speed
-			move.emit(movement)
+	if is_captured:
+		var relative_followed_position: Vector2 = get_followed_mouse_position()
+		var direction: Vector2 = position.direction_to(relative_followed_position)
+		var actual_speed: float = min(delta * speed, relative_followed_position.length())  # Don't overshoot.
+		var movement: Vector2 = direction * actual_speed
+		move.emit(movement)
 
 func _on_capture_area_mouse_entered() -> void:
-	state = State.CAPTURED
-	captured.emit()
+	if state_holder.propose_state(state_name, 70, func (): detached.emit()):
+		captured.emit()
 
 func _on_capture_area_mouse_exited() -> void:
 	if can_detach:
-		state = State.DETACHED
-		detached.emit()
+		state_holder.remove_state(state_name)
+		
 

behaviours/random_walk.gd

@@ -0,0 +1,56 @@
+extends Node2D
+class_name RandomWalk
+
+
+signal move(movement: Vector2)
+
+
+@export var speed: float = 100.0
+
+@export var wait_time_mean: float = 4
+@export var wait_time_dev: float = 1.5
+@export var wander_time_mean: float = 5.0
+@export var wander_time_dev: float = 1.0
+
+@export var state_holder: StateHolder
+
+@onready var rand_walk_timer: Timer = Timer.new()
+
+var walk_dir: Vector2 = Vector2.ZERO
+
+
+func _ready():
+	if state_holder == null:
+		state_holder = StateHolder.get_default(self)
+
+	add_child(rand_walk_timer)
+	rand_walk_timer.one_shot = true;
+	rand_walk_timer.connect("timeout", _on_timer_timeout)
+
+	state_holder.on_changed.connect(init_timer)
+	init_timer()
+
+func _physics_process(delta: float) -> void:
+	if state_holder.state != 'wander':
+		return
+	var movement: Vector2 = speed * walk_dir * delta
+	move.emit(movement)
+
+func init_timer():
+	match state_holder.state:
+		'idle':
+			var rand_time = max(0, Random.rng.randfn(wait_time_mean, wait_time_dev))
+			rand_walk_timer.start(rand_time)
+		'wander':
+			var rand_time = max(0, Random.rng.randfn(wander_time_mean, wander_time_dev))
+			rand_walk_timer.start(rand_time)
+		_:
+			rand_walk_timer.stop()
+
+func _on_timer_timeout():
+	match state_holder.state:
+		'idle':
+			state_holder.set_state('wander', 10)
+			walk_dir = Vector2.from_angle(Random.rng.randf_range(0, 2*PI))
+		'wander':
+			state_holder.reset_state()

behaviours/random_walk.tscn

@@ -0,0 +1,11 @@
+[gd_scene load_steps=2 format=3 uid="uid://dqlhv4j3b62hd"]
+
+[ext_resource type="Script" path="res://behaviours/random_walk.gd" id="1_hs213"]
+
+[node name="RandomWalk" type="Node2D"]
+script = ExtResource("1_hs213")
+speed = null
+wait_time_mean = null
+wait_time_dev = null
+wander_time_mean = null
+wander_time_dev = null

behaviours/skitter_from_mouse.gd

@@ -6,7 +6,7 @@ signal move(movement: Vector2)
 signal scared
 signal calmed
 
-
+@export var state_holder: StateHolder;
 @export_range(1, 500, 1) var speed: float = 300.0
 @export_range(0.1, 5, 0.1) var scare_secs: float = 0.2
 @export var directions: Array[Vector2] = []
@@ -14,25 +14,26 @@ signal calmed
 @onready var calm_timer: Timer = $"CalmTimer"
 @onready var scare_area: HoverDetector = $"ScareArea"
 
-
-enum State { CALM, SCARED }
-
-var state := State.CALM
 var direction := Vector2.ZERO
 
+const SCARED_PRIORITY = 50
+
 
 func recheck():
+	calm_timer.stop()
 	if scare_area.mouse_inside:
 		scare()
 	else:
 		calm()
 
 func calm():
-	state = State.CALM
-	calmed.emit()
+	if state_holder.state == 'scared':
+		state_holder.reset_state()
+		calmed.emit()
 
 func scare():
-	state = State.SCARED
+	if not state_holder.propose_state('scared', SCARED_PRIORITY, recheck):
+		return
 	# Pick a direction
 	var idx := Random.rng.randi_range(0, len(directions) - 1)
 	direction = directions[idx]
@@ -42,15 +43,16 @@ func scare():
 
 
 func _ready():
+	if state_holder == null:
+		state_holder = StateHolder.get_default(self)
 	if not directions: 
 		Log.w(self, "No directions defined, object won't skitter.")
 
 func _physics_process(delta: float) -> void:
-	match state:
-		State.SCARED:
-			if len(directions) > 0:
-				var movement: Vector2 = direction * delta * speed
-				move.emit(movement)
+	if state_holder.state == 'scared':
+		if len(directions) > 0:
+			var movement: Vector2 = direction * delta * speed
+			move.emit(movement)
 
 func _on_calm_timer_timeout() -> void:
 	recheck()

behaviours/state_holder.gd

@@ -0,0 +1,68 @@
+extends Node2D
+class_name StateHolder
+
+signal on_changed(state: StringName, priority: int)
+
+const DEFAULT_STATE: StringName = "idle"
+const DEFAULT_PRIORITY: int = 0
+
+var _state: StringName = DEFAULT_STATE
+var _priority: int
+var _exit_callback: Callable = no_callback
+
+var state: StringName :
+	get:
+		return _state
+
+var priority: int :
+	get:
+		return _priority
+
+func set_state(new_state: StringName, new_priority: int, exit_callback: Callable = no_callback) -> void:
+	# Priority should be checked outside otherwise we never decrease it
+	
+	# Prevent recursion problems
+	var prev_callback = _exit_callback
+	_state = new_state
+	_priority = new_priority
+	_exit_callback = exit_callback
+	prev_callback.call()
+	on_changed.emit(new_state, new_priority)
+
+func propose_state(new_state: StringName, new_priority: int, exit_callback: Callable = no_callback) -> bool:
+	if new_priority > _priority:
+		set_state(new_state, new_priority, exit_callback)
+		return true
+	return false
+
+func reset_state() -> void:
+	set_state(DEFAULT_STATE, DEFAULT_PRIORITY)
+
+func remove_state(previous_state: StringName) -> void:
+	if _state == previous_state:
+		reset_state()
+
+
+func no_callback():
+	pass
+
+
+static func get_default(current: Node2D) -> StateHolder:
+	# Try some default paths
+	for path in [^"../StateHolder", ^"../State"]:
+		var node = current.get_node_or_null(path)
+		if node != null:
+			return node
+	# Try to get a StateHolder from the parent's children
+	for child in current.get_parent().get_children():
+		if child is StateHolder:
+			return child
+	
+	# Create one (hard way)
+	Log.w(current, "No StateHolder found, please create one or connect one")
+	var holder = StateHolder.new()
+	holder.set_name("StateHolder")
+	current.get_parent().add_child(holder)
+	return holder
+	
+	

behaviours/state_holder.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://d31h5lcitnlsd"]
+
+[ext_resource type="Script" path="res://behaviours/state_holder.gd" id="1_md0rn"]
+
+[node name="StateHolder" type="Node2D"]
+script = ExtResource("1_md0rn")

entities/imp.gd

@@ -13,13 +13,6 @@ func _on_eat_target_eaten(target: Edible):
 	if Random.rng.randf() < skull_chance:
 		skull_spawner.spawn()
 
-
-func _on_draggable_move(movement:Vector2):
-	if draggable.being_dragged:
-		move_and_collide(movement)
-		sprite.handle_move(movement)
-
 func _on_move(movement:Vector2):
-	if not draggable.being_dragged:
-		move_and_collide(movement)
-		sprite.handle_move(movement)
+	move_and_collide(movement)
+	sprite.handle_move(movement)

entities/imp.tscn

@@ -1,4 +1,4 @@
-[gd_scene load_steps=10 format=3 uid="uid://4d3ksr3171x4"]
+[gd_scene load_steps=11 format=3 uid="uid://4d3ksr3171x4"]
 
 [ext_resource type="Script" path="res://entities/imp.gd" id="1_dixpc"]
 [ext_resource type="PackedScene" uid="uid://bxbjfev0lhwws" path="res://behaviours/sprite_left_right.tscn" id="2_eqcdi"]
@@ -6,8 +6,9 @@
 [ext_resource type="PackedScene" uid="uid://b7bdlh5akhi8s" path="res://behaviours/eat_target.tscn" id="3_iybf3"]
 [ext_resource type="Texture2D" uid="uid://crhwsob76ieya" path="res://entities/imp_left.png" id="3_qda0k"]
 [ext_resource type="Texture2D" uid="uid://bubehid53q8h1" path="res://entities/imp_right.png" id="4_0sckn"]
-[ext_resource type="PackedScene" path="res://behaviours/spawner.tscn" id="4_d8lgm"]
+[ext_resource type="PackedScene" uid="uid://cyrg770fsetyu" path="res://behaviours/spawner.tscn" id="4_d8lgm"]
 [ext_resource type="PackedScene" uid="uid://uoxwjpmgg27a" path="res://entities/gold.tscn" id="5_yrfoq"]
+[ext_resource type="PackedScene" uid="uid://d31h5lcitnlsd" path="res://behaviours/state_holder.tscn" id="9_myo4m"]
 
 [sub_resource type="CircleShape2D" id="CircleShape2D_ide4n"]
 radius = 8.0
@@ -27,8 +28,9 @@ right_texture = ExtResource("4_0sckn")
 scale = Vector2(4, 4)
 shape = SubResource("CircleShape2D_ide4n")
 
-[node name="Draggable" parent="." instance=ExtResource("3_4528r")]
+[node name="Draggable" parent="." node_paths=PackedStringArray("state_holder") instance=ExtResource("3_4528r")]
 scale = Vector2(4, 4)
+state_holder = NodePath("../StateHolder")
 
 [node name="DragSound" type="AudioStreamPlayer2D" parent="Draggable"]
 scale = Vector2(0.5, 0.5)
@@ -36,13 +38,16 @@ scale = Vector2(0.5, 0.5)
 [node name="DropSound" type="AudioStreamPlayer2D" parent="Draggable"]
 scale = Vector2(0.5, 0.5)
 
-[node name="EatTarget" parent="." instance=ExtResource("3_iybf3")]
+[node name="EatTarget" parent="." node_paths=PackedStringArray("state_holder") instance=ExtResource("3_iybf3")]
 scale = Vector2(2, 2)
 tag = &"Sheep"
+state_holder = NodePath("../StateHolder")
 
 [node name="SkullSpawner" parent="." instance=ExtResource("4_d8lgm")]
 scene = ExtResource("5_yrfoq")
 
-[connection signal="move" from="Draggable" to="." method="_on_draggable_move"]
+[node name="StateHolder" parent="." instance=ExtResource("9_myo4m")]
+
+[connection signal="move" from="Draggable" to="." method="_on_move"]
 [connection signal="eaten" from="EatTarget" to="." method="_on_eat_target_eaten"]
 [connection signal="move" from="EatTarget" to="." method="_on_move"]

entities/sheep.gd

@@ -9,14 +9,8 @@ class_name Sheep
 
 
 func _on_move(movement: Vector2) -> void:
-	if not draggable.being_dragged:
-		move_and_collide(movement)
-		sprite.handle_move(movement)
-
-func _on_drag_move(movement: Vector2) -> void:
-	if draggable.being_dragged:
-		move_and_collide(movement)
-		sprite.handle_move(movement)
+	move_and_collide(movement)
+	sprite.handle_move(movement)
 
 func _on_draggable_dragged() -> void:
 	drag_sound.play()

entities/sheep.tscn

@@ -1,4 +1,4 @@
-[gd_scene load_steps=11 format=3 uid="uid://bc2bm8lbol18w"]
+[gd_scene load_steps=13 format=3 uid="uid://bc2bm8lbol18w"]
 
 [ext_resource type="Script" path="res://entities/sheep.gd" id="1_4dmll"]
 [ext_resource type="Texture2D" uid="uid://iljp5yn3ehfk" path="res://entities/sheep_left.png" id="2_t13f5"]
@@ -9,6 +9,8 @@
 [ext_resource type="AudioStream" uid="uid://buxgivpkh8dyl" path="res://entities/drop.wav" id="4_nxjnl"]
 [ext_resource type="AudioStream" uid="uid://bmfscpnugaejk" path="res://entities/sheep_drag.wav" id="4_oalqu"]
 [ext_resource type="PackedScene" uid="uid://dfdr3e32lohq" path="res://behaviours/edible.tscn" id="6_3odsh"]
+[ext_resource type="PackedScene" uid="uid://dqlhv4j3b62hd" path="res://behaviours/random_walk.tscn" id="6_ekxsq"]
+[ext_resource type="PackedScene" uid="uid://d31h5lcitnlsd" path="res://behaviours/state_holder.tscn" id="10_mm8v8"]
 
 [sub_resource type="CircleShape2D" id="CircleShape2D_c5tcn"]
 radius = 8.0
@@ -28,13 +30,23 @@ right_texture = ExtResource("4_5qoof")
 scale = Vector2(3, 3)
 shape = SubResource("CircleShape2D_c5tcn")
 
-[node name="MoveTowardsMouse" parent="." instance=ExtResource("2_tfd2i")]
+[node name="MoveTowardsMouse" parent="." node_paths=PackedStringArray("state_holder") instance=ExtResource("2_tfd2i")]
 scale = Vector2(30, 30)
 speed = -30.0
 can_detach = true
+state_holder = NodePath("../StateHolder")
+state_name = &"scared"
 
-[node name="Draggable" parent="." instance=ExtResource("3_8ku7r")]
+[node name="RandomWalk" parent="." instance=ExtResource("6_ekxsq")]
+speed = 10.0
+wait_time_mean = 4.0
+wait_time_dev = 1.5
+wander_time_mean = 5.0
+wander_time_dev = 1.0
+
+[node name="Draggable" parent="." node_paths=PackedStringArray("state_holder") instance=ExtResource("3_8ku7r")]
 scale = Vector2(3, 3)
+state_holder = NodePath("../StateHolder")
 
 [node name="DragSound" type="AudioStreamPlayer2D" parent="Draggable"]
 scale = Vector2(0.5, 0.5)
@@ -47,7 +59,10 @@ stream = ExtResource("4_nxjnl")
 [node name="Edible" parent="." instance=ExtResource("6_3odsh")]
 tag = &"Sheep"
 
+[node name="StateHolder" parent="." instance=ExtResource("10_mm8v8")]
+
 [connection signal="move" from="MoveTowardsMouse" to="." method="_on_move"]
+[connection signal="move" from="RandomWalk" to="." method="_on_move"]
 [connection signal="dragged" from="Draggable" to="." method="_on_draggable_dragged"]
 [connection signal="dropped" from="Draggable" to="." method="_on_draggable_dropped"]
-[connection signal="move" from="Draggable" to="." method="_on_drag_move"]
+[connection signal="move" from="Draggable" to="." method="_on_move"]