Model relative property tree root binding.

This fixes the animation bindings to use the defined property tree root - to support multiplayer (or other) model that can bind to the correct part of the property tree.

Requires a corresponding fix in fg to allow the command methods to take an optional root parameter.

What this means is that when inside someone else's multiplayer model (e.g. backseat, or co-pilot), the multipalyer (AI) model will correctly modify properties inside the correct part of the property tree inside (/ai), rather than modifying the properties inside the same part of the tree as the non-ai model.

This means that a properly setup model will operate within it's own space in the property tree; and permit more generic multiplayer code to be written.

This is probably responsible for some of the pollution of the /sim property tree with MP aircraft properties.

simgear/structure/SGBinding.cxx

@@ -69,7 +69,9 @@ SGBinding::read(const SGPropertyNode* node, SGPropertyNode* root)
   }
 
   _arg = const_cast<SGPropertyNode*>(node);
+  _root = const_cast<SGPropertyNode*>(root);
   _setting = 0;
+
 }
 
 void
@@ -89,7 +91,7 @@ SGBinding::innerFire () const
     SG_LOG(SG_INPUT, SG_WARN, "No command attached to binding:" << _command_name);
   } else {
       try {
-          if (!(*_command)(_arg)) {
+          if (!(*_command)(_arg, _root)) {
                 SG_LOG(SG_INPUT, SG_ALERT, "Failed to execute command "
                        << _command_name);
           }

simgear/structure/SGBinding.hxx

@@ -142,6 +142,7 @@ private:
   mutable SGCommandMgr::Command* _command;
   mutable SGPropertyNode_ptr _arg;
   mutable SGPropertyNode_ptr _setting;
+  mutable SGPropertyNode_ptr _root;
 };
 
 typedef SGSharedPtr<SGBinding> SGBinding_ptr;

simgear/structure/commands.cxx

@@ -75,7 +75,7 @@ SGCommandMgr::getCommandNames () const
 }
 
 bool
-SGCommandMgr::execute (const std::string &name, const SGPropertyNode * arg) const
+SGCommandMgr::execute (const std::string &name, const SGPropertyNode * arg, SGPropertyNode *root) const
 {
   Command* command = getCommand(name);
   if (command == 0)
@@ -86,7 +86,7 @@ SGCommandMgr::execute (const std::string &name, const SGPropertyNode * arg) cons
 
   try
   {
-    return (*command)(arg);
+    return (*command)(arg, root);
   }
   catch(sg_exception& e)
   {

simgear/structure/commands.hxx

@@ -41,11 +41,11 @@ public:
     {
     public:
         virtual ~Command() { }
-        virtual bool operator()(const SGPropertyNode * arg) = 0;
+        virtual bool operator()(const SGPropertyNode * arg, SGPropertyNode *root) = 0;
     };
 
     
-	  typedef bool (*command_t) (const SGPropertyNode * arg);
+	  typedef bool (*command_t) (const SGPropertyNode * arg, SGPropertyNode *root);
 
 private:
     class FunctionCommand : public Command
@@ -54,7 +54,7 @@ private:
         FunctionCommand( command_t fun )
     	: f_(fun) {}
 
-        virtual bool operator()(const SGPropertyNode * arg) { return (*f_)(arg); }
+        virtual bool operator()(const SGPropertyNode * arg, SGPropertyNode *root) { return (*f_)(arg, root); }
     private:
         command_t f_;
     };
@@ -66,9 +66,9 @@ private:
         MethodCommand( const ObjPtr& pObj, MemFn pMemFn ) :
     	  pObj_(pObj), pMemFn_(pMemFn) {}
 
-        virtual bool operator()(const SGPropertyNode * arg)
+        virtual bool operator()(const SGPropertyNode * arg, SGPropertyNode *root)
         {
-    	     return ((*pObj_).*pMemFn_)(arg);
+    	     return ((*pObj_).*pMemFn_)(arg,root);
         }
     private:
         ObjPtr pObj_;
@@ -147,7 +147,7 @@ public:
    * @return true if the command is present and executes successfully,
    * false otherwise.
    */
-  virtual bool execute (const std::string &name, const SGPropertyNode * arg) const;
+  virtual bool execute (const std::string &name, const SGPropertyNode * arg, SGPropertyNode *root) const;
 
   /**
    * Remove a command registration