first rev

direct/src/showbase/Factory.py

@@ -0,0 +1,29 @@
+from direct.directnotify.DirectNotifyGlobal import directNotify
+
+class Factory:
+    """This class manages a list of object types and their corresponding constructors.
+    Objects may be created on-demand from their type. Object types may be any hashable
+    piece of unique data (such as a string).
+    
+    This class is intended to be derived from. Subclasses should call self._registerTypes
+    to set up type constructors."""
+    notify = directNotify.newCategory('Factory')
+    
+    def __init__(self):
+        self._type2ctor = {}
+
+    def create(self, type, *args, **kwArgs):
+        return self._type2ctor[type](*args, **kwArgs)
+
+    def _registerType(self, type, ctor):
+        if self._type2ctor.has_key(type):
+            self.notify.debug('replacing %s ctor %s with %s' %
+                              (type, self._type2ctor[type], ctor))
+        self._type2ctor[type] = ctor
+    def _registerTypes(self, type2ctor):
+        for type, ctor in type2ctor.items():
+            self._registerType(type, ctor)
+        
+    def nullCtor(self, *args, **kwArgs):
+        return None
+