completion: caontext manager to block entry change habdler

taburet/ui/completion.py

@@ -3,6 +3,8 @@
 import gtk
 from gtk.keysyms import Escape, Up, Down, Return, KP_Up, KP_Enter, KP_Down
 
+from contextlib import contextmanager
+
 def entry_changed(entry, completion_ref):
     completion = completion_ref()
 
@@ -216,4 +218,12 @@ def on_key_event(self, popup, event):
 
     def on_button_event(self, popup, event):
         self.hide()
-        return True
+        return True
+
+    @contextmanager
+    def block(self, entry):
+        entry.handler_block_by_func(entry_changed)
+        try:
+            yield
+        finally:
+            entry.handler_unblock_by_func(entry_changed)

taburet/ui/grid.py

@@ -47,6 +47,9 @@ def _set_value(self, entry, row):
 
     @guard('changing')
     def set_dirty_value(self, entry, row):
+        self._set_dirty_value(entry, row)
+
+    def _set_dirty_value(self, entry, row):
         entry.set_text(row[self.name])
 
     def update_row_value(self, dirty_row, row):