X-Git-Url: https://git.cweiske.de/enigma2.git/blobdiff_plain/9d3112aad388b4369a339b851aa2507a02bb2d4f..a7ed9db9532b7ac58dc3b923c0e3f9ee1789ddeb:/lib/python/Components/Element.py

diff --git a/lib/python/Components/Element.py b/lib/python/Components/Element.py
index baab4cfb..3297a4ad 100644
--- a/lib/python/Components/Element.py
+++ b/lib/python/Components/Element.py
@@ -8,13 +8,21 @@ from Tools.CList import CList
 def cached(f):
 	name = f.__name__
 	def wrapper(self):
-		if self.cache is None:
+		cache = self.cache
+		if cache is None:
 			return f(self)
-		if name not in self.cache:
-			self.cache[name] = (True, f(self))
-		return self.cache[name][1]
+		if name not in cache:
+			cache[name] = (True, f(self))
+		return cache[name][1]
 	return wrapper
 
+class ElementError(Exception):
+    def __init__(self, message):
+        self.msg = message
+
+    def __str__(self):
+        return self.msg
+
 class Element(object):
 	CHANGED_DEFAULT = 0   # initial "pull" state
 	CHANGED_ALL = 1       # really everything changed
@@ -22,9 +30,12 @@ class Element(object):
 	CHANGED_SPECIFIC = 3  # second tuple will specify what exactly changed
 	CHANGED_POLL = 4      # a timer expired
 
+	SINGLE_SOURCE = True
+
 	def __init__(self):
 		self.downstream_elements = CList()
 		self.master = None
+		self.sources = [ ]
 		self.source = None
 		self.__suspended = True
 		self.cache = None
@@ -35,7 +46,9 @@ class Element(object):
 			self.master = downstream
 	
 	def connectUpstream(self, upstream):
-		assert self.source is None
+		assert not self.SINGLE_SOURCE or self.source is None
+		self.sources.append(upstream)
+		# self.source always refers to the last recent source added.
 		self.source = upstream
 		self.changed((self.CHANGED_DEFAULT,))
 	
@@ -48,11 +61,17 @@ class Element(object):
 		# 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"
-		
+
 		# Sources don't have a source themselves. don't do anything here.
-		if self.source is not None:
-			self.source.disconnectDownstream(self)
-	
+		for s in self.sources:
+			s.disconnectDownstream(self)
+
+		if self.source:
+			# sources are owned by the Screen, so don't destroy them here.
+			self.destroy()
+		self.source = None
+		self.sources = [ ]
+
 	def disconnectDownstream(self, downstream):
 		self.downstream_elements.remove(downstream)
 		if self.master == downstream:
@@ -67,10 +86,6 @@ class Element(object):
 		self.downstream_elements.changed(*args, **kwargs)
 		self.cache = None
 
-	def reconnectUpstream(self, new_upstream):
-		assert self.source is not None
-		self.source = new_upstream
-
 	def setSuspend(self, suspended):
 		changed = self.__suspended != suspended
 		if not self.__suspended and suspended:
@@ -79,8 +94,9 @@ class Element(object):
 			self.doSuspend(0)
 			
 		self.__suspended = suspended
-		if self.source is not None and changed:
-			self.source.checkSuspend()
+		if changed:
+			for s in self.sources:
+				s.checkSuspend()
 	
 	suspended = property(lambda self: self.__suspended, setSuspend)
 	
@@ -89,3 +105,6 @@ class Element(object):
 
 	def doSuspend(self, suspend):
 		pass
+
+	def destroy(self):
+		pass