modified files, save-as, etc

--HG--
branch : pmacs2

application.py

@@ -442,7 +442,7 @@ class Application(object):
     # buffer handling
     def new_file_buffer(self, path, data, switch_to=True):
         assert not self.has_buffer_name(path), '%r is already open' % path
-        assert not os.path.exists(path), '%r already exists' % path
+        #assert not os.path.exists(path), '%r already exists' % path
         # touch the file
         f = open(path, 'w')
         f.write(data)

method/buffers.py

@@ -115,6 +115,7 @@ class SaveBufferAs(Method):
 class SaveBuffer(Method):
     '''Save the contents of a buffer'''    
     def _execute(self, w, **vargs):
+        a = w.application
         if not w.buffer.changed():
             w.set_error("(No changes need to be saved)")
             return
@@ -125,7 +126,18 @@ class SaveBuffer(Method):
             w.buffer.save(force=True)
             w.set_error("File had disappeared! Wrote %s" % (w.buffer.path))
         except buffer.FileChangedError, e:
-            pass
+            path1 = w.buffer.path
+            tf = tempfile.NamedTemporaryFile(delete=False)
+            tf.write(w.buffer.make_string())
+            tf.close()
+            path2 = tf.name
+            a.methods['diff'].execute(w, path1=path1, path2=path2)
+            w.set_error("File changed on disk; showing differences")
+class ReloadBuffer(Method):
+    '''Reload the contents of a buffer from the filesystem'''
+    def _execute(self, w, **vargs):
+        w.buffer.reload()
+        w.set_error("Buffer contents reloaded from %r" % w.buffer.path)
 
 class ToggleTabs(Method):
     '''Toggle whether to write tabs out or not (defaults to false)'''