[kupfer] plugin.image: Detect if Autorotate makes sense or not

[Ulrik Sverdrup <usverdrup src gnome org>]

commit cf781bb338dc31f12276e96920bd1a52d05409be
Author: Ulrik Sverdrup <ulrik sverdrup gmail com>
Date:   Tue Sep 15 16:41:52 2009 +0200

    plugin.image: Detect if Autorotate makes sense or not
    
    We simply launch jhead and check the file's headers. If jhead is not
    installed, or Orientation is as it should, the action does not apply.

 kupfer/plugin/image.py |   17 +++++++++++++----
 1 files changed, 13 insertions(+), 4 deletions(-)
---
diff --git a/kupfer/plugin/image.py b/kupfer/plugin/image.py
index f4c6113..e48af33 100644
--- a/kupfer/plugin/image.py
+++ b/kupfer/plugin/image.py
@@ -4,7 +4,7 @@ from os import path as os_path
 import subprocess
 
 from kupfer.objects import Leaf, Action, FileLeaf, TextLeaf
-from kupfer import utils
+from kupfer import utils, pretty
 
 __kupfer_name__ = _("Image Tools")
 __kupfer_sources__ = ()
@@ -135,10 +135,19 @@ class Autorotate (Action):
 		yield FileLeaf
 
 	def valid_for_item(self, item):
-		# FIXME: Make this detection smarter
 		root, ext = os_path.splitext(item.object)
-		return ext.lower() in (".jpeg", ".jpg")
+		if not ext.lower() in (".jpeg", ".jpg"):
+			return False
+		# Launch jhead to see if 1) it is installed, 2) Orientation nondefault
+		try:
+			cmdargs = ("jhead", item.object)
+			proc = subprocess.Popen(cmdargs, stdout=subprocess.PIPE)
+		except OSError:
+			pretty.print_debug(__name__ , "Action %s needs 'jhead'" % self)
+		else:
+			out, err = proc.communicate()
+			return any(li.startswith("Orientation") for li in out.splitlines())
 
 	def get_description(self):
-		return _("Rotate JPEG image (in-place) according to its EXIF metadata")
+		return _("Rotate JPEG (in-place) according to its EXIF metadata")