naja/resources/loader.py

   1 import os
   2 import sys
   3
   4 try:
   5     from pkg_resources import resource_filename
   6 except ImportError:
   7     # OK, we're most likely running under py2exe, so this is safe
   8     # (for values of safe that are unconcerned about py2exe being involved)
   9     def resource_filename(mod, path):
  10         # There are better ways of doing this, but I've spent too much
  11         # time going down this rabbithole already
  12         return os.path.join(os.path.dirname(__file__), '..', '..', 'data',
  13                             path)
  14 import pygame
  15
  16
  17 class ResourceNotFound(Exception):
  18     pass
  19
  20
  21 class Loader(object):
  22     CONVERT_ALPHA = True
  23
  24     def __init__(self, resource_module, language=None):
  25         self.resource_module = resource_module
  26         self.lang_dialect = language
  27         self.language = language.split('_', 1)[0] if language else None
  28         self._cache = {}
  29
  30     def create_resource_path(self, *path_fragments):
  31         return resource_filename(self.resource_module,
  32                                  os.path.join(*path_fragments))
  33
  34     def get_resource_path(self, *path_fragments):
  35         for mod, full_path_fragments in self.lang_locations(path_fragments):
  36             path = resource_filename(mod, os.path.join(*full_path_fragments))
  37             if os.path.exists(path):
  38                 return path
  39         raise ResourceNotFound(os.path.join(*path_fragments))
  40
  41     def lang_locations(self, path_fragments):
  42         '''
  43         For each resource module, yield:
  44         * (<module>, (<lang>_<dialect>, <path>))
  45         * (<module>, (<lang>, <path>))
  46         * (<module>, (<path>, ))
  47         '''
  48         for module in (self.resource_module,):
  49             if self.lang_dialect:
  50                 yield (module, (self.lang_dialect,) + path_fragments)
  51             if self.language != self.lang_dialect:
  52                 yield (module, (self.language,) + path_fragments)
  53             yield (module, path_fragments)
  54
  55     def get_file(self, *path_fragments, **kw):
  56         mode = kw.get('mode', "rU")
  57         try:
  58             path = self.get_resource_path(*path_fragments)
  59         except ResourceNotFound:
  60             if 'w' in mode:
  61                 path = self.create_resource_path(*path_fragments)
  62             else:
  63                 raise
  64         return file(path, mode)
  65
  66     def get_image(self, *name_fragments, **kw):
  67         transforms = kw.get('transforms', ())
  68         basedir = kw.get('basedir', 'images')
  69
  70         path = (basedir,) + name_fragments
  71
  72         if path not in self._cache:
  73             fn = self.get_resource_path(*path)
  74             image = pygame.image.load(fn)
  75             if self.CONVERT_ALPHA:
  76                 if not pygame.display.get_init():
  77                     print >> sys.stderr, ("Display not initialized, "
  78                                           "image '%s' not loaded."
  79                                           % os.path.join(*path))
  80                     return
  81                 image = image.convert_alpha(pygame.display.get_surface())
  82             self._cache[path] = image
  83
  84         key = (path, transforms)
  85         if key not in self._cache:
  86             image = self._cache[path]
  87             for mutator in transforms:
  88                 image = mutator(image)
  89             self._cache[key] = image
  90
  91         return self._cache[key]
  92
  93     def get_font(self, file_name, font_size):
  94         basedir = 'fonts'
  95         key = (basedir, file_name, font_size)
  96
  97         if key not in self._cache:
  98             fn = self.get_resource_path(basedir, file_name)
  99             self._cache[key] = pygame.font.Font(fn, font_size)
 100
 101         return self._cache[key]