PropertyObject: enable creation of property

add a create-flag to the node() method of a PropertyObject,
defaulting to false to maintain existing behaviour.
This could be used to add a listener to a non-existing property
without having to write a dummy-value beforehand.

Usage:
myPropertyObject->node() returns the corresponding node or NULL if
does not exist or has not been accessed before.
myPropertyObject->node(true) returns the corresponding node, never NULL.
If the property does not exist, it will gets created.

diff --git a/simgear/props/propertyObject.hxx b/simgear/props/propertyObject.hxx
index 9e6586594e379473d50dd3a3dd1fc66b52ad315a..d97f9d11f109a598bfbb92ab770961354966c20c 100644 (file)
--- a/simgear/props/propertyObject.hxx
+++ b/simgear/props/propertyObject.hxx
@@ -144,9 +144,9 @@ public:
 
 #undef SG_DEF_ASSIGN_OP
 
-  SGPropertyNode* node() const
+  SGPropertyNode* node(bool aCreate = false) const
   {
-    return PropertyObjectBase::node(false);
+    return PropertyObjectBase::node(aCreate);
   }
 }; // of template PropertyObject