Handle image extensions better.

Author: jonathanrocher

stage4.1_first_application/pycasa/ui/tasks/pycasa_task.py

@@ -48,6 +48,9 @@ def _default_layout_default(self):
     # Task interface ----------------------------------------------------------
 
     def open_in_central_pane(self, filepath):
-        if splitext(filepath)[1] in SUPPORTED_FORMATS:
+        file_ext = splitext(filepath)[1]
+        if file_ext.lower() in SUPPORTED_FORMATS:
             obj = ImageFile(filepath=filepath)
             self.central_pane.edit(obj, factory=ImageFileEditor)
+        else:
+            print("Unsupported file format: {}".format(file_ext))