X-Git-Url: https://git.cweiske.de/enigma2.git/blobdiff_plain/ddb050fe8357a01b1fc52070ee9f87450c407c1c..b4d8c89302c67237b8a121a8f262e9db0022a9e7:/lib/python/Components/Element.py

diff --git a/lib/python/Components/Element.py b/lib/python/Components/Element.py
index 019155c6..437d934b 100644
--- a/lib/python/Components/Element.py
+++ b/lib/python/Components/Element.py
@@ -4,6 +4,17 @@ from Tools.CList import CList
 # Render Converter Converter Source
 
 # a bidirectional connection
+
+def cached(f):
+	name = f.__name__
+	def wrapper(self):
+		if self.cache is None:
+			return f(self)
+		if name not in self.cache:
+			self.cache[name] = (True, f(self))
+		return self.cache[name][1]
+	return wrapper
+
 class Element(object):
 	CHANGED_DEFAULT = 0   # initial "pull" state
 	CHANGED_ALL = 1       # really everything changed
@@ -16,7 +27,7 @@ class Element(object):
 		self.master = None
 		self.source = None
 		self.__suspended = True
-		self.clearCache()
+		self.cache = None
 
 	def connectDownstream(self, downstream):
 		self.downstream_elements.append(downstream)
@@ -37,11 +48,13 @@ 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)
-	
+			# sources are owned by the Screen, so don't destroy them here.
+			self.destroy()
+
 	def disconnectDownstream(self, downstream):
 		self.downstream_elements.remove(downstream)
 		if self.master == downstream:
@@ -52,17 +65,14 @@ class Element(object):
 
 	# default action: push downstream
 	def changed(self, *args, **kwargs):
-		self.clearCache()
+		self.cache = { }
 		self.downstream_elements.changed(*args, **kwargs)
-		self.clearCache()
+		self.cache = None
 
 	def reconnectUpstream(self, new_upstream):
 		assert self.source is not None
 		self.source = new_upstream
 
-	def clearCache(self):
-		self.cache = None
-
 	def setSuspend(self, suspended):
 		changed = self.__suspended != suspended
 		if not self.__suspended and suspended:
@@ -81,3 +91,6 @@ class Element(object):
 
 	def doSuspend(self, suspend):
 		pass
+
+	def destroy(self):
+		pass