Skip unsupported image formats

spritecss/main.py

@@ -46,6 +46,8 @@ def map_sprites(self):
             def test_sref(sref):
                 if not access(str(sref), R_OK):
                     logger.error("%s: not readable", sref); return False
+                if not str(sref).lower().endswith('.png'):
+                    logger.warn('%s: unsupported format', sref); return False
                 else:
                     logger.debug("%s passed", sref); return True
             return self.mapper.map_reduced(ifilter(test_sref, srefs))

spritecss/packing/sprites.py

@@ -1,8 +1,13 @@
 from contextlib import contextmanager
+import logging
 
 from ..image import Image
+from ..png import FormatError
 from . import Rect
 
+logger = logging.getLogger(__name__)
+
+
 class SpriteNode(Rect):
     def __init__(self, im, width, height, fname=None, pad=(0, 0)):
         Rect.__init__(self, (0, 0, width, height))
@@ -39,8 +44,14 @@ def load_file(cls, fo, fname=None, pad=(0, 0), **kwds):
 @contextmanager
 def open_sprites(fnames, **kwds):
     fs = [(fn, open(str(fn), "rb")) for fn in fnames]
+    sprites = []
     try:
-        yield [SpriteNode.load_file(fo, fname=fn, **kwds) for (fn, fo) in fs]
+        for fn, fo in fs:
+            try:
+                sprites.append(SpriteNode.load_file(fo, fname=fn, **kwds))
+            except FormatError, e:
+                logger.warn('%s: invalid image file: %s', fn, e)
+        yield sprites
     finally:
         for fn, fo in fs:
             fo.close()