Better static typing in the timeline related methods in Project

src/Autoload/OpenSave.gd

@@ -68,11 +68,11 @@ func handle_loading_file(file: String) -> void:
 
 func add_import_option(import_name: StringName, import_scene: PackedScene) -> int:
 	# Change format name if another one uses the same name
-	var existing_format_names = (
+	var existing_format_names := (
 		ImportPreviewDialog.ImageImportOptions.keys() + custom_import_names.keys()
 	)
 	for i in range(existing_format_names.size()):
-		var test_name = import_name
+		var test_name := import_name
 		if i != 0:
 			test_name = str(test_name, "_", i)
 		if !existing_format_names.has(test_name):
@@ -82,7 +82,7 @@ func add_import_option(import_name: StringName, import_scene: PackedScene) -> in
 	# Obtain a unique id
 	var id := ImportPreviewDialog.ImageImportOptions.size()
 	for i in custom_import_names.size():
-		var format_id = id + i
+		var format_id := id + i
 		if !custom_import_names.values().has(i):
 			id = format_id
 	# Add to custom_file_formats
@@ -514,7 +514,7 @@ func open_image_as_spritesheet_layer_smart(
 	# Create new frames (if needed)
 	var new_frames_size := maxi(project.frames.size(), start_frame + sliced_rects.size())
 	var frames := []
-	var frame_indices := []
+	var frame_indices := PackedInt32Array([])
 	if new_frames_size > project.frames.size():
 		var required_frames := new_frames_size - project.frames.size()
 		frame_indices = range(
@@ -595,7 +595,7 @@ func open_image_as_spritesheet_layer(
 	# Create new frames (if needed)
 	var new_frames_size := maxi(project.frames.size(), start_frame + (vertical * horizontal))
 	var frames := []
-	var frame_indices := []
+	var frame_indices := PackedInt32Array([])
 	if new_frames_size > project.frames.size():
 		var required_frames := new_frames_size - project.frames.size()
 		frame_indices = range(

src/Classes/Project.gd

@@ -586,7 +586,8 @@ func _z_index_sort(a: int, b: int, frame_index: int) -> bool:
 # use remove, and vice versa. To undo a move or swap, use move or swap with the parameters swapped.
 
 
-func add_frames(new_frames: Array, indices: Array) -> void:  # indices should be in ascending order
+# indices should be in ascending order
+func add_frames(new_frames: Array, indices: PackedInt32Array) -> void:
 	Global.canvas.selection.transform_content_confirm()
 	selected_cels.clear()
 	for i in new_frames.size():
@@ -603,14 +604,14 @@ func add_frames(new_frames: Array, indices: Array) -> void:  # indices should be
 	_update_frame_ui()
 
 
-func remove_frames(indices: Array) -> void:  # indices should be in ascending order
+func remove_frames(indices: PackedInt32Array) -> void:  # indices should be in ascending order
 	Global.canvas.selection.transform_content_confirm()
 	selected_cels.clear()
 	for i in indices.size():
 		# With each removed index, future indices need to be lowered, so subtract by i
 		# For each linked cel in the frame, update its layer's cel_link_sets
 		for l in layers.size():
-			var cel: BaseCel = frames[indices[i] - i].cels[l]
+			var cel := frames[indices[i] - i].cels[l]
 			cel.on_remove()
 			if cel.link_set != null:
 				cel.link_set["cels"].erase(cel)
@@ -650,11 +651,11 @@ func swap_frame(a_index: int, b_index: int) -> void:
 	_set_timeline_first_and_last_frames()
 
 
-func reverse_frames(frame_indices: Array) -> void:
+func reverse_frames(frame_indices: PackedInt32Array) -> void:
 	Global.canvas.selection.transform_content_confirm()
 	for i in frame_indices.size() / 2:
-		var index: int = frame_indices[i]
-		var reverse_index: int = frame_indices[-i - 1]
+		var index := frame_indices[i]
+		var reverse_index := frame_indices[-i - 1]
 		var temp := frames[index]
 		frames[index] = frames[reverse_index]
 		frames[reverse_index] = temp
@@ -666,7 +667,8 @@ func reverse_frames(frame_indices: Array) -> void:
 	change_cel(-1)
 
 
-func add_layers(new_layers: Array, indices: Array, cels: Array) -> void:  # cels is 2d Array of cels
+## [param cels] is 2d Array of [BaseCel]s
+func add_layers(new_layers: Array, indices: PackedInt32Array, cels: Array) -> void:
 	Global.canvas.selection.transform_content_confirm()
 	selected_cels.clear()
 	for i in indices.size():
@@ -678,7 +680,7 @@ func add_layers(new_layers: Array, indices: Array, cels: Array) -> void:  # cels
 	_update_layer_ui()
 
 
-func remove_layers(indices: Array) -> void:
+func remove_layers(indices: PackedInt32Array) -> void:
 	Global.canvas.selection.transform_content_confirm()
 	selected_cels.clear()
 	for i in indices.size():
@@ -692,7 +694,9 @@ func remove_layers(indices: Array) -> void:
 
 
 # from_indices and to_indicies should be in ascending order
-func move_layers(from_indices: Array, to_indices: Array, to_parents: Array) -> void:
+func move_layers(
+	from_indices: PackedInt32Array, to_indices: PackedInt32Array, to_parents: Array
+) -> void:
 	Global.canvas.selection.transform_content_confirm()
 	selected_cels.clear()
 	var removed_layers := []

src/UI/Timeline/AnimationTimeline.gd

@@ -300,7 +300,7 @@ func _on_DeleteFrame_pressed() -> void:
 	delete_frames()
 
 
-func delete_frames(indices := []) -> void:
+func delete_frames(indices: PackedInt32Array = []) -> void:
 	var project := Global.current_project
 	if project.frames.size() == 1:
 		return
@@ -551,7 +551,7 @@ func move_frames(frame: int, rate: int) -> void:
 	project.undo_redo.commit_action()
 
 
-func reverse_frames(indices := []) -> void:
+func reverse_frames(indices: PackedInt32Array = []) -> void:
 	var project := Global.current_project
 	project.undo_redo.create_action("Change Frame Order")
 	project.undo_redo.add_do_method(project.reverse_frames.bind(indices))
@@ -885,7 +885,9 @@ func _on_CloneLayer_pressed() -> void:
 		else:  # Add (Copy) to the name if its not a child of another copied layer
 			cl_layer.name = str(cl_layer.name, " (", tr("copy"), ")")
 
-	var indices := range(project.current_layer + 1, project.current_layer + clones.size() + 1)
+	var indices: PackedInt32Array = range(
+		project.current_layer + 1, project.current_layer + clones.size() + 1
+	)
 
 	project.undos += 1
 	project.undo_redo.create_action("Add Layer")
@@ -934,7 +936,7 @@ func change_layer_order(up: bool) -> void:
 	var project := Global.current_project
 	var layer := project.layers[project.current_layer]
 	var child_count := layer.get_child_count(true)
-	var from_indices := range(layer.index - child_count, layer.index + 1)
+	var from_indices: PackedInt32Array = range(layer.index - child_count, layer.index + 1)
 	var from_parents := []
 	for l in from_indices:
 		from_parents.append(project.layers[l].parent)
@@ -971,7 +973,7 @@ func change_layer_order(up: bool) -> void:
 			else:
 				to_index = to_index - 1
 
-	var to_indices := range(to_index, to_index + child_count + 1)
+	var to_indices: PackedInt32Array = range(to_index, to_index + child_count + 1)
 
 	project.undo_redo.create_action("Change Layer Order")
 	project.undo_redo.add_do_method(project.move_layers.bind(from_indices, to_indices, to_parents))

src/UI/Timeline/FrameButton.gd

@@ -169,7 +169,7 @@ func _get_region_rect(x_begin: float, x_end: float) -> Rect2:
 	return rect
 
 
-func _get_frame_indices() -> Array:
+func _get_frame_indices() -> PackedInt32Array:
 	var indices := []
 	for cel in Global.current_project.selected_cels:
 		var f: int = cel[0]

src/UI/Timeline/LayerMainButton.gd

@@ -72,8 +72,8 @@ func _drop_data(_pos: Vector2, data) -> void:
 	var drop_layer: int = data[1]
 	var project := Global.current_project
 	project.undo_redo.create_action("Change Layer Order")
-	var layers: Array = project.layers  # This shouldn't be modified directly
-	var drop_from_indices := range(
+	var layers := project.layers  # This shouldn't be modified directly
+	var drop_from_indices: PackedInt32Array = range(
 		drop_layer - layers[drop_layer].get_child_count(true), drop_layer + 1
 	)
 	var drop_from_parents := []
@@ -99,7 +99,7 @@ func _drop_data(_pos: Vector2, data) -> void:
 		for l in a.from:
 			a_from_parents.append(layers[l].parent)
 
-		# to_parents starts as a dulpicate of from_parents, set the root layer's (with one layer or
+		# to_parents starts as a duplicate of from_parents, set the root layer's (with one layer or
 		# group with its children, this will always be the last layer [-1]) parent to the other
 		# root layer's parent
 		a["to_parents"] = a_from_parents.duplicate()
@@ -144,7 +144,7 @@ func _drop_data(_pos: Vector2, data) -> void:
 		if drop_layer < layer_index:
 			to_index -= drop_from_indices.size()
 
-		var drop_to_indices := range(to_index, to_index + drop_from_indices.size())
+		var drop_to_indices: PackedInt32Array = range(to_index, to_index + drop_from_indices.size())
 		var to_parents := drop_from_parents.duplicate()
 		to_parents[-1] = to_parent
 

src/UI/Timeline/PasteTagPopup.gd

@@ -112,7 +112,8 @@ func add_animation(indices: Array, destination: int, from_tag: AnimationTag = nu
 	var combined_copy := Array()  # Makes calculations easy
 	combined_copy.append_array(project.layers)
 	var added_layers := Array()  # Array of layers
-	var added_idx := Array()  # Array of indices to add the respective layers (in added_layers) to
+	# Array of indices to add the respective layers (in added_layers) to
+	var added_idx := PackedInt32Array()
 	var added_cels := Array()  # Array of an Array of cels (added in same order as their layer)
 
 	if layer_from_to.values().count(-1) > 0: