Fix a memory leak coming from the Layer class

Removed the "frame_container" property from Layer.gd, which used to hold a reference to a node, leading to orphan nodes being created and never freed. Memory management seems to be working okay now. Previously, every time the user made a change, memory kept going up and never coming down. Now, data that can never be recovered, like undo data that have been rewritten in history, are also removed from memory.

src/Autoload/OpenSave.gd

@@ -170,14 +170,7 @@ func open_old_pxo_file(file: File, new_project: Project, first_line: String) ->
 			var layer_new_cels_linked := file.get_8()
 			linked_cels.append(file.get_var())
 
-			var l := Layer.new(
-				layer_name,
-				layer_visibility,
-				layer_lock,
-				HBoxContainer.new(),
-				layer_new_cels_linked,
-				[]
-			)
+			var l := Layer.new(layer_name, layer_visibility, layer_lock, layer_new_cels_linked, [])
 			new_project.layers.append(l)
 			global_layer_line = file.get_line()
 

src/Classes/Layer.gd

@@ -5,23 +5,16 @@ extends Reference
 var name := ""
 var visible := true
 var locked := false
-var frame_container: HBoxContainer
 var new_cels_linked := false
 var linked_cels := []  # Array of Frames
 
 
 func _init(
-	_name := "",
-	_visible := true,
-	_locked := false,
-	_frame_container := HBoxContainer.new(),
-	_new_cels_linked := false,
-	_linked_cels := []
+	_name := "", _visible := true, _locked := false, _new_cels_linked := false, _linked_cels := []
 ) -> void:
 	name = _name
 	visible = _visible
 	locked = _locked
-	frame_container = _frame_container
 	new_cels_linked = _new_cels_linked
 	linked_cels = _linked_cels
 

src/Classes/Project.gd

@@ -85,8 +85,6 @@ func _init(_frames := [], _name := tr("untitled"), _size := Vector2(64, 64)) ->
 
 
 func remove() -> void:
-	for layer in layers:
-		layer.frame_container.queue_free()
 	undo_redo.free()
 	for guide in guides:
 		guide.queue_free()
@@ -160,7 +158,8 @@ func change_project() -> void:
 		layer_container.label.text = layers[i].name
 		layer_container.line_edit.text = layers[i].name
 
-		Global.frames_container.add_child(layers[i].frame_container)
+		var layer_cel_container := HBoxContainer.new()
+		Global.frames_container.add_child(layer_cel_container)
 		for j in range(frames.size()):  # Create Cel buttons
 			var cel_button = cel_button_node.instance()
 			cel_button.frame = j
@@ -169,7 +168,7 @@ func change_project() -> void:
 			if j == current_frame and i == current_layer:
 				cel_button.pressed = true
 
-			layers[i].frame_container.add_child(cel_button)
+			layer_cel_container.add_child(cel_button)
 
 	for j in range(frames.size()):  # Create frame ID labels
 		var button: Button = frame_button_node.instance()
@@ -335,7 +334,6 @@ func serialize() -> Dictionary:
 			cel_data.append(
 				{
 					"opacity": cel.opacity,
-					#				"image_data" : cel.image.get_data()
 				}
 			)
 		frame_data.append({"cels": cel_data, "duration": frame.duration})
@@ -402,7 +400,6 @@ func deserialize(dict: Dictionary) -> void:
 					saved_layer.name,
 					saved_layer.visible,
 					saved_layer.locked,
-					HBoxContainer.new(),
 					saved_layer.new_cels_linked,
 					linked_cels
 				)
@@ -463,7 +460,15 @@ func _frames_changed(value: Array) -> void:
 		frame_id.queue_free()
 
 	for i in range(layers.size() - 1, -1, -1):
-		Global.frames_container.add_child(layers[i].frame_container)
+		var layer_cel_container := HBoxContainer.new()
+		layer_cel_container.name = "FRAMESS " + str(i)
+		Global.frames_container.add_child(layer_cel_container)
+		for j in range(frames.size()):
+			var cel_button = cel_button_node.instance()
+			cel_button.frame = j
+			cel_button.layer = i
+			cel_button.get_child(0).texture = frames[j].cels[i].image_texture
+			layer_cel_container.add_child(cel_button)
 
 	for j in range(frames.size()):
 		var button: Button = frame_button_node.instance()
@@ -472,14 +477,6 @@ func _frames_changed(value: Array) -> void:
 		button.text = str(j + 1)
 		Global.frame_ids.add_child(button)
 
-		for i in range(layers.size() - 1, -1, -1):
-			var cel_button = cel_button_node.instance()
-			cel_button.frame = j
-			cel_button.layer = i
-			cel_button.get_child(0).texture = frames[j].cels[i].image_texture
-
-			layers[i].frame_container.add_child(cel_button)
-
 	_set_timeline_first_and_last_frames()
 
 
@@ -497,23 +494,24 @@ func _layers_changed(value: Array) -> void:
 	_remove_cel_buttons()
 
 	for i in range(layers.size() - 1, -1, -1):
-		var layer_container = layer_button_node.instance()
-		layer_container.layer = i
+		var layer_button: LayerButton = layer_button_node.instance()
+		layer_button.layer = i
 		if layers[i].name == "":
 			layers[i].name = tr("Layer") + " %s" % i
 
-		Global.layers_container.add_child(layer_container)
-		layer_container.label.text = layers[i].name
-		layer_container.line_edit.text = layers[i].name
+		Global.layers_container.add_child(layer_button)
+		layer_button.label.text = layers[i].name
+		layer_button.line_edit.text = layers[i].name
 
-		Global.frames_container.add_child(layers[i].frame_container)
+		var layer_cel_container := HBoxContainer.new()
+		layer_cel_container.name = "LAYERSSS " + str(i)
+		Global.frames_container.add_child(layer_cel_container)
 		for j in range(frames.size()):
 			var cel_button = cel_button_node.instance()
 			cel_button.frame = j
 			cel_button.layer = i
 			cel_button.get_child(0).texture = frames[j].cels[i].image_texture
-
-			layers[i].frame_container.add_child(cel_button)
+			layer_cel_container.add_child(cel_button)
 
 	var layer_button = Global.layers_container.get_child(
 		Global.layers_container.get_child_count() - 1 - current_layer
@@ -525,10 +523,8 @@ func _layers_changed(value: Array) -> void:
 
 func _remove_cel_buttons() -> void:
 	for container in Global.frames_container.get_children():
-		for button in container.get_children():
-			container.remove_child(button)
-			button.queue_free()
 		Global.frames_container.remove_child(container)
+		container.queue_free()
 
 
 func _frame_changed(value: int) -> void:
@@ -544,9 +540,9 @@ func _frame_changed(value: int) -> void:
 		):
 			text_color = Color.black
 		Global.frame_ids.get_child(i).add_color_override("font_color", text_color)
-		for layer in layers:  # De-select all the other frames
-			if i < layer.frame_container.get_child_count():
-				layer.frame_container.get_child(i).pressed = false
+		for container in Global.frames_container.get_children():  # De-select all the other frames
+			if i < container.get_child_count():
+				container.get_child(i).pressed = false
 
 	if selected_cels.empty():
 		selected_cels.append([current_frame, current_layer])
@@ -558,9 +554,13 @@ func _frame_changed(value: int) -> void:
 			Global.frame_ids.get_child(current_frame_tmp).add_color_override(
 				"font_color", Global.control.theme.get_color("Selected Color", "Label")
 			)
-		if layers:
-			if current_frame_tmp < layers[current_layer_tmp].frame_container.get_child_count():
-				var fbutton = layers[current_layer_tmp].frame_container.get_child(current_frame_tmp)
+		var container_child_count: int = Global.frames_container.get_child_count()
+		if current_layer_tmp < container_child_count:
+			var container = Global.frames_container.get_child(
+				container_child_count - 1 - current_layer_tmp
+			)
+			if current_frame_tmp < container.get_child_count():
+				var fbutton = container.get_child(current_frame_tmp)
 				fbutton.pressed = true
 
 	Global.disable_button(Global.remove_frame_button, frames.size() == 1)
@@ -704,6 +704,23 @@ func is_empty() -> bool:
 	)
 
 
+func duplicate_layers() -> Array:
+	var new_layers: Array = layers.duplicate()
+	# Loop through the array to create new classes for each element, so that they
+	# won't be the same as the original array's classes. Needed for undo/redo to work properly.
+	for i in new_layers.size():
+		var new_linked_cels = new_layers[i].linked_cels.duplicate()
+		new_layers[i] = Layer.new(
+			new_layers[i].name,
+			new_layers[i].visible,
+			new_layers[i].locked,
+			new_layers[i].new_cels_linked,
+			new_linked_cels
+		)
+
+	return new_layers
+
+
 func can_pixel_get_drawn(
 	pixel: Vector2,
 	bitmap: BitMap = selection_bitmap,

src/UI/Canvas/Canvas.gd

@@ -112,10 +112,12 @@ func update_texture(layer_i: int, frame_i := -1, project: Project = Global.curre
 		current_cel.image_texture.create_from_image(current_cel.image, 0)
 
 		if project == Global.current_project:
-			var frame_button = project.layers[layer_i].frame_container.get_child(frame_i)
-			var frame_texture_rect: TextureRect
-			frame_texture_rect = frame_button.find_node("CelTexture")
-			frame_texture_rect.texture = current_cel.image_texture
+			var container_index = Global.frames_container.get_child_count() - 1 - layer_i
+			var layer_cel_container = Global.frames_container.get_child(container_index)
+			var cel_button = layer_cel_container.get_child(frame_i)
+			var cel_texture_rect: TextureRect
+			cel_texture_rect = cel_button.find_node("CelTexture")
+			cel_texture_rect.texture = current_cel.image_texture
 
 
 func update_selected_cels_textures(project: Project = Global.current_project) -> void:
@@ -127,7 +129,9 @@ func update_selected_cels_textures(project: Project = Global.current_project) ->
 			current_cel.image_texture.create_from_image(current_cel.image, 0)
 
 			if project == Global.current_project:
-				var cel_button = project.layers[layer_index].frame_container.get_child(frame_index)
+				var container_index = Global.frames_container.get_child_count() - 1 - layer_index
+				var layer_cel_container = Global.frames_container.get_child(container_index)
+				var cel_button = layer_cel_container.get_child(frame_index)
 				var cel_texture_rect: TextureRect = cel_button.find_node("CelTexture")
 				cel_texture_rect.texture = current_cel.image_texture
 

src/UI/Timeline/AnimationTimeline.gd

@@ -54,8 +54,8 @@ func cel_size_changed(value: int) -> void:
 	for layer_button in Global.layers_container.get_children():
 		layer_button.rect_min_size.y = cel_size
 		layer_button.rect_size.y = cel_size
-	for layer in Global.current_project.layers:
-		for cel_button in layer.frame_container.get_children():
+	for container in Global.frames_container.get_children():
+		for cel_button in container.get_children():
 			cel_button.rect_min_size.x = cel_size
 			cel_button.rect_min_size.y = cel_size
 			cel_button.rect_size.x = cel_size
@@ -83,20 +83,8 @@ func add_frame() -> void:
 	var project: Project = Global.current_project
 	var frame: Frame = project.new_empty_frame()
 	var new_frames: Array = project.frames.duplicate()
-	var new_layers: Array = project.layers.duplicate()
+	var new_layers: Array = project.duplicate_layers()
 	new_frames.insert(project.current_frame + 1, frame)
-	# Loop through the array to create new classes for each element, so that they
-	# won't be the same as the original array's classes. Needed for undo/redo to work properly.
-	for i in new_layers.size():
-		var new_linked_cels = new_layers[i].linked_cels.duplicate()
-		new_layers[i] = Layer.new(
-			new_layers[i].name,
-			new_layers[i].visible,
-			new_layers[i].locked,
-			new_layers[i].frame_container,
-			new_layers[i].new_cels_linked,
-			new_linked_cels
-		)
 
 	for l_i in range(new_layers.size()):
 		if new_layers[l_i].new_cels_linked:  # If the link button is pressed
@@ -161,19 +149,7 @@ func delete_frame(frame := -1) -> void:
 	# Check if one of the cels of the frame is linked
 	# if they are, unlink them too
 	# this prevents removed cels being kept in linked memory
-	var new_layers: Array = Global.current_project.layers.duplicate()
-	# Loop through the array to create new classes for each element, so that they
-	# won't be the same as the original array's classes. Needed for undo/redo to work properly.
-	for i in new_layers.size():
-		var new_linked_cels = new_layers[i].linked_cels.duplicate()
-		new_layers[i] = Layer.new(
-			new_layers[i].name,
-			new_layers[i].visible,
-			new_layers[i].locked,
-			new_layers[i].frame_container,
-			new_layers[i].new_cels_linked,
-			new_linked_cels
-		)
+	var new_layers: Array = Global.current_project.duplicate_layers()
 
 	for layer in new_layers:
 		for linked in layer.linked_cels:
@@ -221,7 +197,7 @@ func copy_frame(frame := -1) -> void:
 
 	var new_frame := Frame.new()
 	var new_frames := Global.current_project.frames.duplicate()
-	var new_layers: Array = Global.current_project.layers.duplicate()
+	var new_layers: Array = Global.current_project.duplicate_layers()
 	new_frames.insert(frame + 1, new_frame)
 
 	for cel in Global.current_project.frames[frame].cels:  # Copy every cel
@@ -231,19 +207,6 @@ func copy_frame(frame := -1) -> void:
 		sprite_texture.create_from_image(sprite, 0)
 		new_frame.cels.append(Cel.new(sprite, cel.opacity, sprite_texture))
 
-	# Loop through the array to create new classes for each element, so that they
-	# won't be the same as the original array's classes. Needed for undo/redo to work properly.
-	for i in new_layers.size():
-		var new_linked_cels = new_layers[i].linked_cels.duplicate()
-		new_layers[i] = Layer.new(
-			new_layers[i].name,
-			new_layers[i].visible,
-			new_layers[i].locked,
-			new_layers[i].frame_container,
-			new_layers[i].new_cels_linked,
-			new_linked_cels
-		)
-
 	for l_i in range(new_layers.size()):
 		if new_layers[l_i].new_cels_linked:  # If the link button is pressed
 			new_layers[l_i].linked_cels.append(new_frame)
@@ -651,19 +614,7 @@ func change_layer_order(rate: int) -> void:
 
 
 func _on_MergeDownLayer_pressed() -> void:
-	var new_layers: Array = Global.current_project.layers.duplicate()
-	# Loop through the array to create new classes for each element, so that they
-	# won't be the same as the original array's classes. Needed for undo/redo to work properly.
-	for i in new_layers.size():
-		var new_linked_cels = new_layers[i].linked_cels.duplicate()
-		new_layers[i] = Layer.new(
-			new_layers[i].name,
-			new_layers[i].visible,
-			new_layers[i].locked,
-			new_layers[i].frame_container,
-			new_layers[i].new_cels_linked,
-			new_linked_cels
-		)
+	var new_layers: Array = Global.current_project.duplicate_layers()
 
 	Global.current_project.undos += 1
 	Global.current_project.undo_redo.create_action("Merge Layer")

src/UI/Timeline/CelButton.gd

@@ -105,19 +105,7 @@ func _on_PopupMenu_id_pressed(id: int) -> void:
 		MenuOptions.LINK:
 			var f: Frame = Global.current_project.frames[frame]
 			var cel_index: int = Global.current_project.layers[layer].linked_cels.find(f)
-			var new_layers: Array = Global.current_project.layers.duplicate()
-			# Loop through the array to create new classes for each element, so that they
-			# won't be the same as the original array's classes. Needed for undo/redo to work properly.
-			for i in new_layers.size():
-				var new_linked_cels: Array = new_layers[i].linked_cels.duplicate()
-				new_layers[i] = Layer.new(
-					new_layers[i].name,
-					new_layers[i].visible,
-					new_layers[i].locked,
-					new_layers[i].frame_container,
-					new_layers[i].new_cels_linked,
-					new_linked_cels
-				)
+			var new_layers: Array = Global.current_project.duplicate_layers()
 			var new_cels: Array = f.cels.duplicate()
 			for i in new_cels.size():
 				new_cels[i] = Cel.new(

src/UI/Timeline/LayerButton.gd

@@ -116,7 +116,8 @@ func _on_LinkButton_pressed() -> void:
 		layer_class.linked_cels.append(
 			Global.current_project.frames[Global.current_project.current_frame]
 		)
-		layer_class.frame_container.get_child(Global.current_project.current_frame).button_setup()
+		var container = Global.frames_container.get_child(Global.current_project.current_layer)
+		container.get_child(Global.current_project.current_frame).button_setup()
 
 	Global.current_project.layers = Global.current_project.layers  # Call the setter