pocket-friends/pocket_friends/elements/surface.py

"""Module to aid in the drawing of surfaces to make switching from one screen to another easier."""
import pygame
from ..io.input_handler import InputHandler


class GameSurface(pygame.Surface):
    """
    Class to be used as the backbone of all game surfaces.

    The GameSurface class is what the game uses to draw all other elements on top of. It controls a number of game
    operations, including input handling, frame rate limiting, and surface switching. It is a child class of Pygame's
    Surface class and utilizes Pygame's sprite handling along with the ability to blit certain things on the screen
    in order to draw elements easily.

    Attributes:
        running: Boolean to tell whether the surface is running or not.
        next_surface: String that represents the next surface to be switched to after halting.
        resource_dir: String that contains the path of the game's main resource directory.
        game_fps: An integer value of how many frames per second the game will run at.
        additional_args: Dictionary of additional arguments to send to the next surface after halting.
        background: A Pygame surface that will be drawn behind all other elements.
    """
    def __init__(self, game_res: int, resources_dir: str, game_fps: pygame.Surface):
        """
        Create a GameSurface object.
        Args:
            game_res: The internal resolution of the surface.
            resources_dir: The path of the game's main resource directory.
            game_fps: How many frames per second the game will run at.
        """
        super().__init__(game_res, pygame.SRCALPHA)
        self.running = True  # Surfaces should be running by default
        self.next_surface = None
        self.resource_dir = resources_dir
        self.game_fps = game_fps
        self.additional_args = {}
        self.dev_override = False

        self.background = pygame.image.load(self.resource_dir + '/images/bg.png').convert_alpha()

        self._clock = pygame.time.Clock()
        self._input_handler = InputHandler(self._clock)
        self._sprites = pygame.sprite.Group()

    def preprocess(self):
        """
        Advance the surface by one frame and draw the background.
        """
        self._clock.tick(self.game_fps)

        self.blit(self.background, (0, 0))
        self._sprites.update()
        self._sprites.draw(self)

        self._input_handler.update()
        if self._input_handler.dev_found:
            self.dev_override = True
            self.running = False