From 9bcc599fba7204b53fc24f2ce7357fe0a85f0dc4 Mon Sep 17 00:00:00 2001
From: Felix Domke <tmbinc@elitedvb.net>
Date: Mon, 24 Jul 2006 23:56:06 +0000
Subject: [PATCH] support only one upstream element (source)

---
 lib/python/Components/Element.py          | 14 +++++++-------
 lib/python/Components/Renderer/Listbox.py |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/lib/python/Components/Element.py b/lib/python/Components/Element.py
index 5b8bed86..884c87d3 100644
--- a/lib/python/Components/Element.py
+++ b/lib/python/Components/Element.py
@@ -7,7 +7,6 @@ from Tools.CList import CList
 class Element:
 	def __init__(self):
 		self.downstream_elements = CList()
-		self.upstream_elements = CList()
 		self.master = None
 		self.source = None
 
@@ -17,8 +16,8 @@ class Element:
 			self.master = downstream
 	
 	def connectUpstream(self, upstream):
-		self.upstream_elements.append(upstream)
-		self.source = upstream # for single-source elements (i.e., most of them.)
+		assert self.source is None
+		self.source = upstream
 		self.changed()
 	
 	def connect(self, upstream):
@@ -30,10 +29,7 @@ class Element:
 		# we should not disconnect from upstream if
 		# there are still elements depending on us.
 		assert len(self.downstream_elements) == 0, "there are still downstream elements left"
-		
-		# disconnect all upstream elements from us
-		for upstream in self.upstream_elements:
-			upstream.disconnectDownstream(self)
+		self.source.disconnectDownstream(self)
 	
 	def disconnectDownstream(self, downstream):
 		self.downstream_elements.remove(downstream)
@@ -46,3 +42,7 @@ class Element:
 	# default action: push downstream
 	def changed(self, *args, **kwargs):
 		self.downstream_elements.changed(*args, **kwargs)
+
+	def reconnectUpstream(self, new_upstream):
+		assert self.source is not None
+		self.source = new_upstream
diff --git a/lib/python/Components/Renderer/Listbox.py b/lib/python/Components/Renderer/Listbox.py
index fb787bfa..ab696c23 100644
--- a/lib/python/Components/Renderer/Listbox.py
+++ b/lib/python/Components/Renderer/Listbox.py
@@ -50,7 +50,7 @@ class Listbox(Renderer, object):
 	wrap_around = property(lambda self: self.__wrap_around, setWrapAround)
 
 	def selectionChanged(self):
-		self.upstream_elements.selectionChanged(self.index)
+		self.source.selectionChanged(self.index)
 
 	def getIndex(self):
 		if self.instance is None:
-- 
2.30.2