Added support for exporting mac app icons.

image_utils.py

@@ -0,0 +1,38 @@
+from cStringIO import StringIO
+try:
+    from PIL import Image as im
+    Image = im.open
+    def resize(image, size):
+        output = StringIO()
+        back = im.new('RGBA', size, (0,0,0,0))
+        image.thumbnail(size, im.ANTIALIAS)
+        offset = [0,0]
+        if image.size[0] >= image.size[1]:
+            offset[1] = back.size[1]/2-image.size[1]/2
+        else:
+            offset[0] = back.size[0]/2-image.size[0]/2
+        back.paste(image, tuple(offset))
+        back.save(output, image.format)
+        contents = output.getvalue()
+        output.close()
+        return contents
+except ImportError:
+    raise Exception('Python image library PIL/pillow is required.')
+
+LARGEST_ICON_SIZE = 1024
+SMALLEST_ICON_SIZE = 16
+sizes = [LARGEST_ICON_SIZE,512,256,128,48,32,SMALLEST_ICON_SIZE]
+
+def nearest_icon_size(width, height):
+    maximum = max(width, height)
+
+    if maximum >= LARGEST_ICON_SIZE:
+        return LARGEST_ICON_SIZE
+    if maximum <= SMALLEST_ICON_SIZE:
+        return SMALLEST_ICON_SIZE
+
+    for i in xrange(len(sizes)-1):
+        current_size = sizes[i]
+        next_size = sizes[i+1]
+        if current_size > maximum >= next_size:
+            return next_size