Ticket #214: lazy-reader.diff

mwlib/reportlab/lib/utils.py

@@ -526 +526 @@
     except ImportError:
         return 0
 
-class ImageReader:
+class ImageReader(object):
     "Wraps up either PIL or Java to get data from bitmaps"
     def __init__(self, fileName):
         if isinstance(fileName,ImageReader):
@@ -559 +559 @@
                 else:
                     import PIL.Image
                     self._image = PIL.Image.open(self.fp)
-                    if self._image=='JPEG': self.jpeg_fh = self._jpeg_fp
+                    self.getSize()
+
+                    use_jpeg_fp = self._image=='JPEG'
+                    del self._image
+                    del self.fp
+                    self.__class__=LazyImageReader
+                    
+                    if use_jpeg_fp:
+                        self.jpeg_fh = self._jpeg_fp
             except:
                 et,ev,tb = sys.exc_info()
                 if hasattr(ev,'args'):
@@ -641 +649 @@
                 return map(ord, palette[transparency:transparency+3])
             else:
                 return None
+
+class LazyImageReader(ImageReader):
+    @property
+    def fp(self):
+        return open_for_read(self.fileName, 'b')
+        
+    @property
+    def _image(self):        
+        import PIL.Image
+        return PIL.Image.open(self.fp)
 
 def getImageData(imageFileName):
     "Get width, height and RGB pixels from image file.  Wraps Java/PIL"