# Global Variables
class Global_variables(object):
    _instance = None

    WINDOW_X = 1400
    WINDOW_Y = 750
    RECT_SIZE = 50
    DIMENSION_X = 28
    DIMENSION_Y = 15
    RECT_COLOR = (70, 77, 87)
    SHELF_COLOR = (143, 68, 33)

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super(Global_variables, cls).__new__(cls)

        return cls._instance