Added icns save

PIL/IcnsImagePlugin.py

@@ -18,6 +18,7 @@
 from PIL import Image, ImageFile, PngImagePlugin, _binary
 import io
 import struct
+import tempfile, shutil, os, sys
 
 enable_jpeg2k = hasattr(Image.core, 'jp2klib_version')
 if enable_jpeg2k:
@@ -293,12 +294,56 @@ class IcnsImageFile(ImageFile.ImageFile):
         self.tile = ()
         self.load_end()
 
+def _save(im, fp, filename):
+    try:
+        fp.flush()
+    except:
+        pass
+    
+    # create the temporary set of pngs
+    iconset = tempfile.mkdtemp('.iconset')
+    last_w = None
+    last_im = None
+    for w in [16,32,128,256,512]:
+        prefix = 'icon_{}x{}'.format(w,w)
+        
+        if last_w == w:
+            im_scaled = last_im
+        else:
+            im_scaled = im.resize((w,w), Image.LANCZOS)
+        im_scaled.save(os.path.join(iconset, prefix+'.png'))
+        
+        im_scaled = im.resize((w*2,w*2), Image.LANCZOS)
+        im_scaled.save(os.path.join(iconset, prefix+'@2x.png'))
+        last_im = im_scaled
+    
+    # iconutil -c icns -o {} {}
+    from subprocess import Popen, PIPE, CalledProcessError
+
+    convert_cmd = ["iconutil","-c","icns","-o",filename,iconset]
+    stderr = tempfile.TemporaryFile()
+    convert_proc = Popen(convert_cmd, stdout=PIPE, stderr=stderr)
+
+    convert_proc.stdout.close()
+
+    retcode = convert_proc.wait()
+
+    # remove the temporary files
+    shutil.rmtree(iconset)
+    
+    if retcode:
+        raise CalledProcessError(retcode, convert_cmd)
+
 Image.register_open("ICNS", IcnsImageFile, lambda x: x[:4] == b'icns')
 Image.register_extension("ICNS", '.icns')
 
+if sys.platform == 'darwin':
+    Image.register_save("ICNS", _save)
+
+    Image.register_mime("ICNS", "image/icns")
+
+
 if __name__ == '__main__':
-    import os
-    import sys
     imf = IcnsImageFile(open(sys.argv[1], 'rb'))
     for size in imf.info['sizes']:
         imf.size = size

Tests/test_file_icns.py

@@ -2,6 +2,8 @@ from helper import unittest, PillowTestCase
 
 from PIL import Image
 
+import sys
+
 # sample icon file
 file = "Tests/images/pillow.icns"
 data = open(file, "rb").read()
@@ -20,6 +22,20 @@ class TestFileIcns(PillowTestCase):
         self.assertEqual(im.size, (1024, 1024))
         self.assertEqual(im.format, "ICNS")
 
+    @unittest.skipIf(sys.platform != 'darwin',
+                     "requires MacOS")
+    def test_save(self):
+        im = Image.open(file)
+        
+        test_file = self.tempfile("temp.icns")
+        im.save(test_file)
+        
+        reread = Image.open(test_file)
+        
+        self.assertEqual(reread.mode, "RGBA")
+        self.assertEqual(reread.size, (1024, 1024))
+        self.assertEqual(reread.format, "ICNS")
+
     def test_sizes(self):
         # Check that we can load all of the sizes, and that the final pixel
         # dimensions are as expected