Refactor signal connections and set theme override to null

Assets/Player/CameraControls.gd

@@ -28,8 +28,7 @@ var _drag_pos: Vector2
 var enabled: bool = true : set = set_enabled, get = get_enabled
 
 func _ready() -> void:
-	if not _viewport.size_changed.connect(Callable(self, "_on_viewport_size_changed")):
-		push_error("Failed To connect viewport")
+	_viewport.size_changed.connect(_on_viewport_size_changed)
 	_basis = _get_basis()
 
 func _process(delta: float) -> void:

Assets/Player/Minimap/MinimapShipLayer.gd

@@ -29,7 +29,7 @@ func draw_layer():
 	timer = $Timer
 	minimap = get_parent() as Minimap
 
-	timer.timeout.connect(Callable(self, "get_ships"))
+	timer.timeout.connect(get_ships)
 
 func get_ships():
 		# get player ship(s)

Assets/Player/PlayerCamera.gd

@@ -152,10 +152,8 @@ func switch_context(new_context: InteractionContext) -> void:
 	if active_context:
 		active_context._on_exit()
 	active_context = new_context
-	if not active_context.switch_context.is_connected(Callable(self, "switch_context")):
-		active_context.switch_context.connect(Callable(self, "switch_context"))
-	if not active_context.context_aborted.is_connected(Callable(self, "abort_context")):
-		active_context.context_aborted.connect(Callable(self, "abort_context"))
+	SignalUtils.ensure_connected(active_context.switch_context, switch_context)
+	SignalUtils.ensure_connected(active_context.context_aborted, abort_context)
 	active_context._on_enter()
 
 func abort_context() -> void:

Assets/UI/BasicControls/OptionButton.gd

@@ -5,8 +5,7 @@ func _on_OptionButton_item_selected(_index: int) -> void:
 
 func _add_hover() -> void:
 	# Restore color override hack when previously unhovered.
-	#add_theme_color_override("font_hover_color", null) # Why does not null work? How to clear properly?
-	set("custom_colors/font_hover_color", null) # Use this then.
+	remove_theme_color_override("font_hover_color")
 
 	if has_theme_icon("arrow_hover", "OptionButton") and not has_theme_icon_override("arrow"):
 		add_theme_icon_override("arrow", load(ProjectSettings.get_setting("gui/theme/custom")).get_icon("arrow_hover", "OptionButton"))
@@ -16,7 +15,7 @@ func _remove_hover() -> void:
 	add_theme_color_override("font_hover_color", load(ProjectSettings.get_setting("gui/theme/custom")).get_color("font_color", "OptionButton"))
 
 	if has_theme_icon_override("arrow"):
-		add_theme_icon_override("arrow", null)
+		remove_theme_icon_override("arrow")
 
 func _notification(what: int) -> void:
 	match what:

Assets/UI/BookMenu/BookMenu.gd

@@ -19,12 +19,12 @@ func _ready() -> void:
 	for page in %Pages.get_children():
 		if %Pages.get_tab_count() > 1:
 			page_control = page.find_child("PageControl")
-			page_control.get_node("PrevButton").pressed.connect(Callable(self, "_on_PrevButton_pressed"))
-			page_control.get_node("NextButton").pressed.connect(Callable(self, "_on_NextButton_pressed"))
+			SignalUtils.ensure_connected(page_control.get_node("PrevButton").pressed, _on_PrevButton_pressed)
+			SignalUtils.ensure_connected(page_control.get_node("NextButton").pressed, _on_NextButton_pressed)
 
 			page_control.visible = true
 
-	%Pages.tab_changed.connect(Callable(self, "_on_Pages_tab_changed"))
+	SignalUtils.ensure_connected(%Pages.tab_changed, _on_Pages_tab_changed)
 
 	# Force-call to determine initial state of page controls (enabled/disabled)
 	%Pages.tab_changed.emit(%Pages.current_tab)
@@ -35,12 +35,9 @@ func set_has_delete_button(new_has_delete_button: bool) -> void:
 
 	has_delete_button = new_has_delete_button
 
-	var callback_function = "_on_DeleteButton_pressed"
-
 	for page in %Pages.get_children():
 		var delete_button := page.find_child("DeleteButton") as TextureButton
-		if not delete_button.pressed.is_connected(Callable(self, callback_function)):
-			delete_button.pressed.connect(Callable(self, callback_function))
+		SignalUtils.ensure_connected(delete_button.pressed, _on_DeleteButton_pressed)
 		delete_button.visible = has_delete_button
 
 func set_has_cancel_button(new_has_cancel_button: bool) -> void:
@@ -49,9 +46,6 @@ func set_has_cancel_button(new_has_cancel_button: bool) -> void:
 
 	has_cancel_button = new_has_cancel_button
 
-	var pressed_signal := "pressed"
-	var callback_function := "_on_CancelButton_pressed"
-
 	for page in %Pages.get_children():
 		# Place CancelButton on
 		#	left side for one-paged menus
@@ -61,8 +55,7 @@ func set_has_cancel_button(new_has_cancel_button: bool) -> void:
 			cancel_button = page.find_child("RightPageControls").find_child("CancelButton") as TextureButton
 		else:
 			cancel_button = page.find_child("CancelButton") as TextureButton
-		if not cancel_button.is_connected(pressed_signal, Callable(self, callback_function)):
-			cancel_button.connect(pressed_signal, Callable(self, callback_function))
+		SignalUtils.ensure_connected(cancel_button.pressed, _on_CancelButton_pressed)
 		cancel_button.visible = has_cancel_button
 
 
@@ -72,13 +65,9 @@ func set_has_ok_button(new_has_ok_button: bool) -> void:
 
 	has_ok_button = new_has_ok_button
 
-	var pressed_signal := "pressed"
-	var callback_function := "_on_OKButton_pressed"
-
 	for page in %Pages.get_children():
 		var ok_button := page.find_child("OKButton") as TextureButton
-		if not ok_button.is_connected(pressed_signal, Callable(self, callback_function)):
-			ok_button.connect("pressed", Callable(self, "_on_OKButton_pressed"))
+		SignalUtils.ensure_connected(ok_button.pressed, _on_OKButton_pressed)
 		ok_button.visible = has_ok_button
 
 func _on_PrevButton_pressed() -> void:

Assets/UI/Pages/HelpUI/HelpUI.gd

@@ -11,12 +11,8 @@ func _ready() -> void:
 	page_control.get_node("NextButton").disabled = true
 
 	# These contain hyperlinks.
-	(%Pages/HelpUIInfo.find_child("RichTextLabel5") as RichTextLabel).meta_clicked.connect(
-		Callable(self, "_on_RichTextLabel_meta_clicked")
-	)
-	(%Pages/HelpUIInfo.find_child("RichTextLabel6") as RichTextLabel).meta_clicked.connect(
-		Callable(self, "_on_RichTextLabel_meta_clicked")
-	)
+	(%Pages/HelpUIInfo.find_child("RichTextLabel5") as RichTextLabel).meta_clicked.connect(_on_RichTextLabel_meta_clicked)
+	(%Pages/HelpUIInfo.find_child("RichTextLabel6") as RichTextLabel).meta_clicked.connect(_on_RichTextLabel_meta_clicked)
 
 func _on_RichTextLabel_meta_clicked(meta: Variant) -> void:
 	print(meta)

Assets/UI/Pages/NewGameUI/ColorSelection.gd

@@ -5,7 +5,7 @@ extends HBoxContainer
 
 func _ready() -> void:
 	for choice in choices.get_children():
-		choice.gui_input.connect(Callable(self, "_on_choice_gui_input").bind(choice))
+		choice.gui_input.connect(_on_choice_gui_input.bind(choice))
 
 		if choice.color_to_faction == Global.faction:
 			selected_color.color = choice.color

Assets/UI/Pages/OptionsUI/OptionsUI.gd

@@ -73,28 +73,28 @@ func _ready() -> void:
 	# Window mode
 	settings["WindowMode"].options = Global.WINDOW_MODES.values()
 	settings["WindowMode"].selected = Config.window_mode
-	settings["WindowMode"].item_selected.connect(Callable(self, "_on_WindowMode_item_selected"))
+	SignalUtils.ensure_connected(settings["WindowMode"].item_selected, _on_WindowMode_item_selected)
 	settings["WindowMode"].item_selected.emit(Config.window_mode)
 
 	# Populate with available resolutions
 	settings["ScreenResolution"].options = SCREEN_RESOLUTIONS
 	for screen_resolution_index in SCREEN_RESOLUTIONS.size():
 		if Config.screen_resolution == SCREEN_RESOLUTIONS[screen_resolution_index]:
 			settings["ScreenResolution"].selected = screen_resolution_index
-	settings["ScreenResolution"].item_selected.connect(Callable(self, "_on_ScreenResolution_item_selected"))
+	SignalUtils.ensure_connected(settings["ScreenResolution"].item_selected, _on_ScreenResolution_item_selected)
 
 	# Audio parameters
 	settings["MasterVolume"].value = Config.master_volume
-	settings["MasterVolume"].value_changed.connect(Callable(self, "_on_MasterVolume_value_changed"))
+	SignalUtils.ensure_connected(settings["MasterVolume"].value_changed, _on_MasterVolume_value_changed)
 
 	settings["MusicVolume"].value = Config.music_volume
-	settings["MusicVolume"].value_changed.connect(Callable(self, "_on_MusicVolume_value_changed"))
+	SignalUtils.ensure_connected(settings["MusicVolume"].value_changed, _on_MusicVolume_value_changed)
 
 	settings["EffectsVolume"].value = Config.effects_volume
-	settings["EffectsVolume"].value_changed.connect(Callable(self, "_on_EffectsVolume_value_changed"))
+	SignalUtils.ensure_connected(settings["EffectsVolume"].value_changed, _on_EffectsVolume_value_changed)
 
 	settings["VoiceVolume"].value = Config.voice_volume
-	settings["VoiceVolume"].value_changed.connect(Callable(self, "_on_VoiceVolume_value_changed"))
+	SignalUtils.ensure_connected(settings["VoiceVolume"].value_changed, _on_VoiceVolume_value_changed)
 
 func populate_dropdown(dropdown: OptionButton, items: Dictionary) -> void:
 	for item in items.values():

Assets/UI/TabWidgets/Buttons/MainButton/MainButtons/GameSpeedLabel.gd

@@ -9,7 +9,7 @@ func _ready() -> void:
 	call_deferred("connect_game") # waiting for Global.Game to be set
 
 func connect_game() -> void:
-	Global.Game.game_speed_changed.connect(Callable(self, "_on_game_speed_changed"))
+	Global.Game.game_speed_changed.connect(_on_game_speed_changed)
 
 func _on_game_speed_changed(new_game_speed: float) -> void:
 	text = "%1.1fx" % new_game_speed

Assets/UI/TabWidgets/Switches/SwitchTabWidget.gd

@@ -17,7 +17,7 @@ class_name SwitchTabWidget
 #
 #func _listen_to_other_switches() -> void:
 #	for sibling in get_parent().get_children():
-#		sibling.tab_changed.connect(Callable(self, "_on_SwitchTabWidget_tab_changed"))
+#		sibling.tab_changed.connect(_on_SwitchTabWidget_tab_changed)
 
 func _draw() -> void:
 #	if texture_normal:
@@ -35,8 +35,7 @@ func get_tab_container() -> TabContainer:
 
 			for switch in get_parent().get_children():
 				switch.tab_container = tab_container
-				if !tab_container.tab_changed.is_connected(Callable(switch, "_on_TabContainer_tab_changed")):
-					tab_container.tab_changed.connect(Callable(switch, "_on_TabContainer_tab_changed"))
+				SignalUtils.ensure_connected(tab_container.tab_changed, _on_TabContainer_tab_changed)
 
 	return tab_container
 

Assets/UI/TabWidgets/TabWidget.gd

@@ -29,9 +29,9 @@ func _ready() -> void:
 	if body.get_child_count() > 0:
 		for child_container in body.get_children():
 			#prints("Attach signals to", child_container.name, "of", self.name)
-			#child_container.resized.connect(Callable(self, "_on_TabContainer_resized"))
-			#child_container.draw.connect(Callable(self, "_on_TabContainer_draw"))
-			child_container.sort_children.connect(Callable(self, "_on_TabContainer_sort_children"))
+			#child_container.resized.connect(_on_TabContainer_resized)
+			#child_container.draw.connect(_on_TabContainer_draw)
+			child_container.sort_children.connect(_on_TabContainer_sort_children)
 
 #func _process(_delta: float) -> void:
 #	if Engine.is_editor_hint():

Assets/UI/TabWidgets/WidgetDetail.gd

@@ -7,7 +7,7 @@ extends VBoxContainer
 const WIDGET_DETAIL_REQUIRED_Y_POSITION = 157
 
 func _ready() -> void:
-	%Body/TabContainer.resized.connect(Callable(self, "_on_TabContainer_resized"))
+	%Body/TabContainer.resized.connect(_on_TabContainer_resized)
 
 func _process(_delta: float) -> void:
 	if Engine.is_editor_hint():

Assets/World/Buildings/Building.gd

@@ -23,7 +23,7 @@ var rotation_offset := 0
 func _ready():
 	super()
 	add_child(timer)
-	timer.timeout.connect(Callable(self, "_on_Timer_timeout"))
+	timer.timeout.connect(_on_Timer_timeout)
 	timer.start(1.001 - anim_speed)
 
 func _process(_delta: float) -> void:

Utils/SignalUtils.gd

@@ -0,0 +1,15 @@
+class_name SignalUtils
+
+
+## Makes sure the given signal is connected to the given callable and connects it otherwise.
+static func ensure_connected(_signal: Signal, callable: Callable):
+	assert(callable.is_valid())
+	if not _signal.is_connected(callable):
+		_signal.connect(callable)
+
+
+## Makes sure the given signal is not connected to the given callable and disconnects it otherwise.
+static func ensure_disconnected(_signal: Signal, callable: Callable):
+	assert(callable.is_valid())
+	if _signal.is_connected(callable):
+		_signal.disconnect(callable)