tabakrolletjie/loader.py

   1 """ Utilities for loading resource files. """
   2
   3 import json
   4 import os
   5
   6 import pygame.image
   7 import pygame.font
   8 import pygame.display
   9 import pygame.mixer
  10
  11 from .constants import DEBUG
  12
  13
  14 class Loader(object):
  15     """ Load data files from beneath a prefix. """
  16
  17     def __init__(self, prefix):
  18         self._prefix = prefix
  19         self._cache = {}
  20
  21     def full_path(self, *parts):
  22         path = "/".join(parts)
  23         rel_path = os.path.join(*path.split("/"))
  24         abs_path = os.path.join(self._prefix, rel_path)
  25         if DEBUG:
  26             print abs_path
  27         return abs_path
  28
  29     def open_file(self, *parts):
  30         return file(self.full_path(*parts), "rb")
  31
  32     def load_station(self, *parts):
  33         with self.open_file("stations", *parts) as f:
  34             return json.load(f)
  35
  36     def load_image(self, *parts):
  37         """Return a pygame surface of the requested image."""
  38         fn = self.full_path("images", *parts)
  39         img = self._cache.get(fn, None)
  40         if img is None:
  41             img = pygame.image.load(fn)
  42             # We assume pygame.display has been initialised
  43             # Fix this if that changes
  44             img.convert_alpha(pygame.display.get_surface())
  45             self._cache[fn] = img
  46         return img
  47
  48     def load_font(self, *parts, **kwargs):
  49         """Return a pygame font of the given size"""
  50         size = kwargs.get('size', 12)
  51         fn = self.full_path("fonts", *parts)
  52         font = pygame.font.Font(fn, size)
  53         # Do we need to cache this?
  54         return font
  55
  56     def load_sound(self, *parts):
  57         """Return a pygame sound"""
  58         fn = self.full_path("sounds", *parts)
  59         sound = self._cache.get(fn, None)
  60         if not sound:
  61             sound = pygame.mixer.Sound(fn)
  62             self._cache[fn] = sound
  63         return sound
  64
  65
  66 _DATA_PREFIX = os.path.abspath(
  67     os.path.join(os.path.dirname(__file__), "..", "data"))
  68
  69 loader = Loader(_DATA_PREFIX)