detect Pile changes

--HG--
extra : convert_revision : c97811113af155d6b2a7c7b1e79159bcb2e7cc51

3 files changed, 15 insertions, 4 deletions

diff --git a/source/str_util.c b/source/str_util.c
index 91e975e..4203808 100644
--- a/source/str_util.c
+++ b/source/str_util.c
@@ -170,7 +170,7 @@ static PyObject * get_width(PyObject *self, PyObject *args)
 
 //======================================================================
 static char decode_one_doc[] =
-"decode_one(string text, int pos) -> (int ord, int nextpos)\n\n\  
+"decode_one(string text, int pos) -> (int ord, int nextpos)\n\n\
 Return (ordinal at pos, next position) for UTF-8 encoded text.\n\n\
 text -- string text\n\
 pos -- position in text";
diff --git a/urwid/listbox.py b/urwid/listbox.py
index d7521ba..316096c 100644
--- a/urwid/listbox.py
+++ b/urwid/listbox.py
@@ -34,7 +34,7 @@ class ListWalker(object):
 
 	def _modified(self):
 		Signals.emit(self, "modified")
-
+	
 
 class SimpleListWalker(ListDetectModifications, ListWalker):
 	def __init__(self, contents):
@@ -52,6 +52,16 @@ class SimpleListWalker(ListDetectModifications, ListWalker):
 			self.focus = len(self)-1
 		super(SimpleListWalker, self)._modified()
 	
+	def set_modified_callback(self, callback):
+		"""
+		This function inherited from ListDetectModifications is not 
+		implemented in SimleListWalker.
+		
+		Use Signals.connect(list_walker, "modified", ...) instead.
+		"""
+		raise NotImplementedError('Use Signals.connect('
+			'list_walker, "modified", ...) instead.')
+	
 	def get_focus(self):
 		"""Return (focus widget, focus position)."""
 		if len(self) == 0: return None, None
diff --git a/urwid/widget.py b/urwid/widget.py
index 207665e..50627bd 100755
--- a/urwid/widget.py
+++ b/urwid/widget.py
@@ -2076,7 +2076,7 @@ class Pile(Widget): # either FlowWidget or BoxWidget
 		one 'weight' tuple in widget_list.
 		"""
 		self.__super.__init__()
-		self.widget_list = widget_list
+		self.widget_list = ListDetectModifications(widget_list)
 		self.item_types = []
 		for i in range(len(widget_list)):
 			w = widget_list[i]
@@ -2092,7 +2092,8 @@ class Pile(Widget): # either FlowWidget or BoxWidget
 				self.item_types.append((f,height))
 			else:
 				raise PileError, "widget list item invalid %s" % `w`
-			
+		self.widget_list.set_modified_callback(self.invalidate)
+		
 		self.set_focus(focus_item)
 		self.pref_col = None