Use signals to move some code away from Project.change_project()

WIP, more code can be moved

src/Autoload/Global.gd

@@ -584,9 +584,6 @@ var cel_button_scene: PackedScene = load("res://src/UI/Timeline/CelButton.tscn")
 @onready var top_menu_container: Panel = control.find_child("TopMenuContainer")
 ## The label indicating cursor position.
 @onready var cursor_position_label: Label = top_menu_container.find_child("CursorPosition")
-## The label indicating current frame number.
-@onready var current_frame_mark_label: Label = top_menu_container.find_child("CurrentFrameMark")
-
 ## The animation timeline. It has the [param AnimationTimeline.gd] script attached.
 @onready var animation_timeline: Panel = control.find_child("Animation Timeline")
 ## The timer used by the animation timeline.

src/Classes/Project.gd

@@ -190,10 +190,7 @@ func selection_map_changed() -> void:
 
 func change_project() -> void:
 	Global.animation_timeline.project_changed()
-
-	Global.current_frame_mark_label.text = "%s/%s" % [str(current_frame + 1), frames.size()]
 	animation_tags = animation_tags
-
 	# Change the guides
 	for guide in Global.canvas.get_children():
 		if guide is Guide:
@@ -206,14 +203,12 @@ func change_project() -> void:
 						guide.visible = Global.show_y_symmetry_axis and Global.show_guides
 			else:
 				guide.visible = false
-
 	# Change the project brushes
 	Brushes.clear_project_brush()
 	for brush in brushes:
 		Brushes.add_project_brush(brush)
 
 	Global.transparent_checker.update_rect()
-	Global.animation_timeline.fps_spinbox.value = fps
 	Global.perspective_editor.update_points()
 	Global.cursor_position_label.text = "[%s×%s]" % [size.x, size.y]
 
@@ -230,7 +225,7 @@ func change_project() -> void:
 	else:
 		Global.top_menu_container.file_menu.set_item_text(Global.FileMenu.SAVE, tr("Save"))
 
-	if !was_exported:
+	if not was_exported:
 		Global.top_menu_container.file_menu.set_item_text(Global.FileMenu.EXPORT, tr("Export"))
 	else:
 		if export_overwrite:
@@ -247,12 +242,7 @@ func change_project() -> void:
 	for j in Tiles.MODE.values():
 		Global.top_menu_container.tile_mode_submenu.set_item_checked(j, j == tiles.mode)
 
-	# Change selection effect & bounding rectangle
-	Global.canvas.selection.marching_ants_outline.offset = selection_offset
 	selection_map_changed()
-	Global.canvas.selection.big_bounding_rectangle = selection_map.get_used_rect()
-	Global.canvas.selection.big_bounding_rectangle.position += selection_offset
-	Global.canvas.selection.queue_redraw()
 	var edit_menu_popup: PopupMenu = Global.top_menu_container.edit_menu
 	edit_menu_popup.set_item_disabled(Global.EditMenu.NEW_BRUSH, !has_selection)
 
@@ -268,18 +258,6 @@ func change_project() -> void:
 		if !canvas_references.has(ri) and !ri.is_inside_tree():
 			Global.canvas.reference_image_container.add_child(ri)
 
-	# Tell the reference images that the project changed
-	Global.reference_panel.project_changed()
-
-	var i := 0
-	for camera in Global.cameras:
-		camera.rotation = cameras_rotation[i]
-		camera.zoom = cameras_zoom[i]
-		camera.offset = cameras_offset[i]
-		camera.rotation_changed.emit()
-		camera.zoom_changed.emit()
-		i += 1
-
 
 func serialize() -> Dictionary:
 	var layer_data := []
@@ -548,7 +526,6 @@ func change_cel(new_frame: int, new_layer := -1) -> void:
 
 	if new_frame != current_frame:  # If the frame has changed
 		current_frame = new_frame
-		Global.current_frame_mark_label.text = "%s/%s" % [str(current_frame + 1), frames.size()]
 
 	if new_layer != current_layer:  # If the layer has changed
 		current_layer = new_layer

src/UI/Canvas/CanvasCamera.gd

@@ -43,6 +43,7 @@ var should_tween := true
 
 
 func _ready() -> void:
+	Global.project_switched.connect(_project_switched)
 	if not DisplayServer.is_touchscreen_available():
 		set_process_input(false)
 	if index == Cameras.MAIN:
@@ -249,6 +250,12 @@ func _has_selection_tool() -> bool:
 	return false
 
 
+func _project_switched() -> void:
+	camera_angle = Global.current_project.cameras_rotation[index]
+	zoom = Global.current_project.cameras_zoom[index]
+	offset = Global.current_project.cameras_offset[index]
+
+
 func _rotate_camera_around_point(degrees: float, point: Vector2) -> void:
 	var angle := deg_to_rad(degrees)
 	offset = (offset - point).rotated(angle) + point

src/UI/Canvas/Selection.gd

@@ -80,6 +80,7 @@ class Gizmo:
 
 
 func _ready() -> void:
+	Global.project_switched.connect(_project_switched)
 	# It's being set to true only when the big_bounding_rectangle has a size larger than 0
 	set_process_input(false)
 	Global.camera.zoom_changed.connect(_update_on_zoom)
@@ -852,6 +853,13 @@ func clear_selection(use_undo := false) -> void:
 		commit_undo("Clear Selection", undo_data_tmp)
 
 
+func _project_switched() -> void:
+	marching_ants_outline.offset = Global.current_project.selection_offset
+	big_bounding_rectangle = Global.current_project.selection_map.get_used_rect()
+	big_bounding_rectangle.position += Global.current_project.selection_offset
+	queue_redraw()
+
+
 func _get_preview_image() -> void:
 	var project := Global.current_project
 	var blended_image := Image.create(project.size.x, project.size.y, false, Image.FORMAT_RGBA8)

src/UI/ReferenceImages/ReferencesPanel.gd

@@ -20,13 +20,14 @@ var transform_button_group: ButtonGroup
 
 
 func _ready() -> void:
+	Global.project_switched.connect(project_changed)
+	OpenSave.reference_image_imported.connect(_on_references_changed)
 	transform_button_group = transform_tools_btns.get_child(0).button_group
 	transform_button_group.pressed.connect(_on_transform_tool_button_group_pressed)
 	list_btn_group.pressed.connect(_on_reference_image_button_pressed)
 	Global.canvas.reference_image_container.reference_image_changed.connect(
 		_on_reference_image_changed
 	)
-	OpenSave.reference_image_imported.connect(_on_references_changed)
 	# We call this function to update the buttons
 	_on_references_changed()
 	_update_ui()
@@ -57,7 +58,7 @@ func reorder_reference_image(from: int, to: int, update_reference_index := true)
 	var project := Global.current_project
 	project.undo_redo.create_action("Reorder Reference Image")
 	project.undo_redo.add_do_method(project.reorder_reference_image.bind(from, to))
-	project.undo_redo.add_do_method(Global.reference_panel._on_references_changed)
+	project.undo_redo.add_do_method(_on_references_changed)
 	if update_reference_index:
 		project.undo_redo.add_do_method(project.set_reference_image_index.bind(to))
 	else:
@@ -67,7 +68,7 @@ func reorder_reference_image(from: int, to: int, update_reference_index := true)
 	project.undo_redo.add_do_method(_update_ui)
 
 	project.undo_redo.add_undo_method(project.reorder_reference_image.bind(to, from))
-	project.undo_redo.add_undo_method(Global.reference_panel._on_references_changed)
+	project.undo_redo.add_undo_method(_on_references_changed)
 	if update_reference_index:
 		project.undo_redo.add_undo_method(project.set_reference_image_index.bind(from))
 	else:

src/UI/Timeline/AnimationTimeline.gd

@@ -1060,6 +1060,7 @@ func _toggle_layer_buttons() -> void:
 
 func project_changed() -> void:
 	var project := Global.current_project
+	fps_spinbox.value = project.fps
 	_toggle_frame_buttons()
 	_toggle_layer_buttons()
 	# These must be removed from tree immediately to not mess up the indices of

src/UI/TopMenuContainer/TopMenuContainer.gd

@@ -49,6 +49,7 @@ var about_dialog := Dialog.new("res://src/UI/Dialogs/AboutDialog.tscn")
 @onready var panels_submenu := PopupMenu.new()
 @onready var layouts_submenu := PopupMenu.new()
 @onready var recent_projects_submenu := PopupMenu.new()
+@onready var current_frame_mark := $HBoxContainer/CurrentFrameMark as Label
 
 
 class Dialog:
@@ -76,6 +77,8 @@ class Dialog:
 
 
 func _ready() -> void:
+	Global.project_switched.connect(_update_current_frame_mark)
+	Global.cel_switched.connect(_update_current_frame_mark)
 	_setup_file_menu()
 	_setup_edit_menu()
 	_setup_view_menu()
@@ -85,6 +88,11 @@ func _ready() -> void:
 	_setup_help_menu()
 
 
+func _update_current_frame_mark() -> void:
+	var project := Global.current_project
+	current_frame_mark.text = "%s/%s" % [str(project.current_frame + 1), project.frames.size()]
+
+
 func _setup_file_menu() -> void:
 	# Order as in FileMenu enum
 	var file_menu_items := {