allow multiple sources for elements. last added source will be in .source, a list...

[enigma2.git] / lib / python / Components / Element.py

diff --git a/lib/python/Components/Element.py b/lib/python/Components/Element.py
index 437d934bb507529969571bdeaa487c1503dc825e..3297a4adf80a4af6dce071f9d629920aa9e8003f 100644 (file)
--- 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,))
        
@@ -50,10 +63,14 @@ class Element(object):
                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)
@@ -69,10 +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:
@@ -81,8 +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)