add game menu

core/game_menu/train_selector.gd

@@ -0,0 +1,38 @@
+extends VBoxContainer
+
+@onready var color_pickers: Array[TrainColorPicker] = [$%ColorPicker1, $%ColorPicker2, $%ColorPicker3, $%ColorPicker4, $%ColorPicker5, $%ColorPicker6]
+@onready var left_arrow: ArrowButton = $%ArrowButtonLeft
+@onready var right_arrow: ArrowButton = $%ArrowButtonRight
+var selected_color: Color
+var selected_color_index: int = 0
+
+func _ready() -> void:
+	for color_picker in color_pickers:
+		color_picker.on_color_selected.connect(_on_color_selected)
+		color_picker.deselect()
+	
+	selected_color = color_pickers[0].color
+	color_pickers[0].select()
+
+	left_arrow.on_pressed.connect(_select_prev_color)
+	right_arrow.on_pressed.connect(_select_next_color)
+
+func _on_color_selected(selected_color_picker: TrainColorPicker) -> void:
+	for i in range(color_pickers.size()):
+		if color_pickers[i].color == selected_color_picker.color:
+			selected_color_picker.select()
+			selected_color_index = i
+		else:
+			color_pickers[i].deselect()
+
+func _select_prev_color() -> void:
+	for color_picker in color_pickers:
+		color_picker.deselect()
+	selected_color_index = (selected_color_index - 1 + color_pickers.size()) % color_pickers.size()
+	color_pickers[selected_color_index].select()
+
+func _select_next_color() -> void:
+	for color_picker in color_pickers:
+		color_picker.deselect()
+	selected_color_index = (selected_color_index + 1) % color_pickers.size()
+	color_pickers[selected_color_index].select()