Only have one CelButton scene instead of using inheritance

src/Autoload/Global.gd

@@ -427,12 +427,8 @@ var base_layer_button_node: PackedScene = load("res://src/UI/Timeline/BaseLayerB
 var pixel_layer_button_node: PackedScene = load("res://src/UI/Timeline/PixelLayerButton.tscn")
 ## The preload of button used by the [GroupLayer].
 var group_layer_button_node: PackedScene = load("res://src/UI/Timeline/GroupLayerButton.tscn")
-## The preload of button used by the [PixelCel].
+## The [PackedScene] of the button used by cels in the timeline.
-var pixel_cel_button_node: PackedScene = load("res://src/UI/Timeline/PixelCelButton.tscn")
+var cel_button_scene: PackedScene = load("res://src/UI/Timeline/CelButton.tscn")
-## The preload of button used by the [GroupCel].
-var group_cel_button_node: PackedScene = load("res://src/UI/Timeline/GroupCelButton.tscn")
-## The preload of button used by the [Cel3D].
-var cel_3d_button_node: PackedScene = load("res://src/UI/Timeline/Cel3DButton.tscn")
 
 @onready var main_window := get_window()  ## The main Pixelorama [Window].
 ## The control node (aka Main node). It has the [param Main.gd] script attached.

src/Classes/Cels/BaseCel.gd

@@ -85,7 +85,7 @@ func on_remove() -> void:
 
 ## Returns an instance of the cel button that will be added to the timeline.
 func instantiate_cel_button() -> Node:
-	return null
+	return Global.cel_button_scene.instantiate()
 
 
 ## Returns to get the type of the cel class.

src/Classes/Cels/Cel3D.gd

@@ -290,9 +290,5 @@ func on_remove() -> void:
 		viewport.queue_free()
 
 
-func instantiate_cel_button() -> Node:
-	return Global.cel_3d_button_node.instantiate()
-
-
 func get_class_name() -> String:
 	return "Cel3D"

src/Classes/Cels/GroupCel.gd

@@ -16,9 +16,5 @@ func get_image() -> Image:
 	return image
 
 
-func instantiate_cel_button() -> Node:
-	return Global.group_cel_button_node.instantiate()
-
-
 func get_class_name() -> String:
 	return "GroupCel"

src/Classes/Cels/PixelCel.gd

@@ -57,9 +57,5 @@ func update_texture() -> void:
 	super.update_texture()
 
 
-func instantiate_cel_button() -> Node:
-	return Global.pixel_cel_button_node.instantiate()
-
-
 func get_class_name() -> String:
 	return "PixelCel"

src/UI/Timeline/Cel3DButton.tscn

@@ -1,14 +0,0 @@
-[gd_scene load_steps=3 format=3 uid="uid://cqpi2e7amvsau"]
-
-[ext_resource type="PackedScene" uid="uid://byhnvhs6av108" path="res://src/UI/Timeline/BaseCelButton.tscn" id="1"]
-[ext_resource type="Script" path="res://src/UI/Timeline/CelButton.gd" id="2"]
-
-[node name="PixelCelButton" instance=ExtResource("1")]
-pivot_offset = Vector2(-18, 6)
-script = ExtResource("2")
-
-[node name="LinkedIndicator" type="Polygon2D" parent="." index="1"]
-color = Color(0, 1, 0, 1)
-invert_enabled = true
-invert_border = 1.0
-polygon = PackedVector2Array(0, 0, 36, 0, 36, 36, 0, 36)

src/UI/Timeline/CelButton.gd

@@ -17,6 +17,8 @@ func _ready() -> void:
 	button_setup()
 	_dim_checker()
 	cel.texture_changed.connect(_dim_checker)
+	if cel is GroupCel:
+		transparent_checker.visible = false
 
 
 func button_setup() -> void:
@@ -84,7 +86,7 @@ func _on_CelButton_pressed() -> void:
 			release_focus()
 
 	elif Input.is_action_just_released("right_mouse"):
-		if is_instance_valid(popup_menu):
+		if cel is PixelCel:
 			popup_menu.popup(Rect2(get_global_mouse_position(), Vector2.ONE))
 		button_pressed = !button_pressed
 	elif Input.is_action_just_released("middle_mouse"):

src/UI/Timeline/CelButton.tscn

@@ -1,10 +1,11 @@
-[gd_scene load_steps=4 format=3 uid="uid://byhnvhs6av108"]
+[gd_scene load_steps=5 format=3 uid="uid://dw7ci3uixjuev"]
 
-[ext_resource type="Shader" path="res://src/Shaders/TransparentChecker.gdshader" id="1"]
+[ext_resource type="Script" path="res://src/UI/Timeline/CelButton.gd" id="1_iewgo"]
-[ext_resource type="PackedScene" uid="uid://3pmb60gpst7b" path="res://src/UI/Nodes/TransparentChecker.tscn" id="2"]
+[ext_resource type="PackedScene" uid="uid://3pmb60gpst7b" path="res://src/UI/Nodes/TransparentChecker.tscn" id="2_mi8wp"]
+[ext_resource type="Shader" path="res://src/Shaders/TransparentChecker.gdshader" id="3_qv21g"]
 
 [sub_resource type="ShaderMaterial" id="1"]
-shader = ExtResource("1")
+shader = ExtResource("3_qv21g")
 shader_parameter/size = 10.0
 shader_parameter/alpha = 1.0
 shader_parameter/color1 = Color(0.7, 0.7, 0.7, 1)
@@ -15,17 +16,19 @@ shader_parameter/rect_size = Vector2(0, 0)
 shader_parameter/follow_movement = false
 shader_parameter/follow_scale = false
 
-[node name="BaseCelButton" type="Button"]
+[node name="CelButton" type="Button"]
 custom_minimum_size = Vector2(36, 36)
 offset_top = 18.0
 offset_right = 36.0
 offset_bottom = 54.0
+pivot_offset = Vector2(-18, 6)
 size_flags_horizontal = 0
 size_flags_vertical = 0
 focus_mode = 0
 mouse_default_cursor_shape = 2
 toggle_mode = true
 button_mask = 7
+script = ExtResource("1_iewgo")
 
 [node name="CelTexture" type="TextureRect" parent="."]
 custom_minimum_size = Vector2(32, 32)
@@ -39,7 +42,7 @@ size_flags_vertical = 0
 expand_mode = 1
 stretch_mode = 6
 
-[node name="TransparentChecker" parent="CelTexture" instance=ExtResource("2")]
+[node name="TransparentChecker" parent="CelTexture" instance=ExtResource("2_mi8wp")]
 show_behind_parent = true
 material = SubResource("1")
 layout_mode = 1
@@ -49,5 +52,21 @@ anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
 
+[node name="PopupMenu" type="PopupMenu" parent="."]
+item_count = 3
+item_0/text = "Delete"
+item_0/id = -1
+item_1/text = "Link Cels to"
+item_1/id = -1
+item_2/text = "Unlink Cels"
+item_2/id = 2
+
+[node name="LinkedIndicator" type="Polygon2D" parent="."]
+color = Color(0, 1, 0, 1)
+invert_enabled = true
+invert_border = 1.0
+polygon = PackedVector2Array(0, 0, 36, 0, 36, 36, 0, 36)
+
 [connection signal="pressed" from="." to="." method="_on_CelButton_pressed"]
 [connection signal="resized" from="." to="." method="_on_CelButton_resized"]
+[connection signal="id_pressed" from="PopupMenu" to="." method="_on_PopupMenu_id_pressed"]

src/UI/Timeline/GroupCelButton.tscn

@@ -1,10 +0,0 @@
-[gd_scene load_steps=3 format=3 uid="uid://b5qw4utq8u88h"]
-
-[ext_resource type="PackedScene" uid="uid://byhnvhs6av108" path="res://src/UI/Timeline/BaseCelButton.tscn" id="1"]
-[ext_resource type="Script" path="res://src/UI/Timeline/CelButton.gd" id="2"]
-
-[node name="GroupCelButton" instance=ExtResource("1")]
-script = ExtResource("2")
-
-[node name="TransparentChecker" parent="CelTexture" index="0"]
-visible = false

src/UI/Timeline/PixelCelButton.tscn

@@ -1,25 +0,0 @@
-[gd_scene load_steps=3 format=3 uid="uid://dw7ci3uixjuev"]
-
-[ext_resource type="PackedScene" uid="uid://byhnvhs6av108" path="res://src/UI/Timeline/BaseCelButton.tscn" id="1"]
-[ext_resource type="Script" path="res://src/UI/Timeline/CelButton.gd" id="2"]
-
-[node name="PixelCelButton" instance=ExtResource("1")]
-pivot_offset = Vector2(-18, 6)
-script = ExtResource("2")
-
-[node name="PopupMenu" type="PopupMenu" parent="." index="1"]
-item_count = 3
-item_0/text = "Delete"
-item_0/id = -1
-item_1/text = "Link Cels to"
-item_1/id = -1
-item_2/text = "Unlink Cels"
-item_2/id = 2
-
-[node name="LinkedIndicator" type="Polygon2D" parent="." index="2"]
-color = Color(0, 1, 0, 1)
-invert_enabled = true
-invert_border = 1.0
-polygon = PackedVector2Array(0, 0, 36, 0, 36, 36, 0, 36)
-
-[connection signal="id_pressed" from="PopupMenu" to="." method="_on_PopupMenu_id_pressed"]