jogai/jogai/scene.py

import os
from typing import Tuple

import pygame

from jogai import settings, utils, videogame
from jogai._globals import _window
from jogai.translations import gettext as _


class Scene:
    """
    A videogame scene with background color and an optional image.
    """

    _image = None
    _rect = None
    filename = ''
    background = settings.SCENE_DEFAULT_BACKGROUND

    def __init__(
        self,
        image_filename: str = '',
        background: Tuple[int, int, int] = settings.SCENE_DEFAULT_BACKGROUND,
    ):
        if not isinstance(image_filename, str):
            raise TypeError(_('The image filename must be a string'))

        self.change_background(background)
        if image_filename:
            self.change_image(image_filename)

    @property
    def height(self):
        return self._rect.height

    @property
    def width(self):
        return self._rect.width

    @property
    def x(self):
        return self._rect.x

    def change_background(self, background: Tuple[int, int, int]):
        """
        Change the background color.

        Parameters:
            background: A tuple with the R,G,B components.

        Examples:
            >>> sc = Scene()
            >>> sc.change_background((255, 255, 255))
        """
        match background:
            case r, g, b if (
                isinstance(r, int)
                and isinstance(g, int)
                and isinstance(b, int)
                and 0 <= r <= 255
                and 0 <= g <= 255
                and 0 <= b <= 255
            ):
                self.background = (r, g, b)
            case _:
                raise ValueError(
                    _(
                        'The background color must be a tuple with three integers (r,g,b) between 0 and 255.'
                    )
                )

    def change_image(self, filename: str) -> bool:
        """
        Change the scene image.

        Parameters:
            filename: The image filename to be changed.

        Examples:
            >>> sc = Scene()
            >>> sc.change_image('test.png')
        """
        self._image, self._rect = utils._load_image(
            settings.SCENES_DIR, filename
        )
        self.filename = filename

    def set_position(self, x: int):
        """
        Set the scene abscissa position.
        The scene painted will never exceed the edges of the image.
        The x coordinate is a non-positive number (scene is moving to the left).

        Parameters:
            x: coordinate in horizontal axis

        Examples:
            >>> sc = Scene('test_large.png')
            >>> sc.set_position(300)
        """
        if not isinstance(x, int):
            raise TypeError(_('The x coordinate must be an integer.'))

        # Set x in range to prevent the scene from being outside the window.
        # The minus sign is essential to correctly position the scene.
        self._rect.x = -min(
            max(0, x), self._rect.width - settings.WINDOW_WIDTH
        )