ROOT_528-00b_version: tree/treeplayer/src/TFriendProxy.cxx Source File

00001 // @(#)root/base:$Id: TFriendProxy.cxx 29044 2009-06-17 01:39:14Z pcanal $
00002 // Author: Philippe Canal  13/05/2003
00003 
00004 /*************************************************************************
00005  * Copyright (C) 1995-2000, Rene Brun, Fons Rademakers and al.           *
00006  * All rights reserved.                                                  *
00007  *                                                                       *
00008  * For the licensing terms see $ROOTSYS/LICENSE.                         *
00009  * For the list of contributors see $ROOTSYS/README/CREDITS.             *
00010  *************************************************************************/
00011 
00012 //////////////////////////////////////////////////////////////////////////
00013 //                                                                      //
00014 // TFriendProxy                                                         //
00015 //                                                                      //
00016 // Concrete implementation of the proxy around a Friend Tree.           //
00017 //                                                                      //
00018 //////////////////////////////////////////////////////////////////////////
00019 
00020 #include "TFriendProxy.h"
00021 #include "TTree.h"
00022 #include "TList.h"
00023 #include "TFriendElement.h"
00024 
00025 ClassImp(ROOT::TFriendProxy);
00026 
00027 namespace ROOT {
00028 
00029    //------------------------------------------------------------------------------------
00030    TFriendProxy::TFriendProxy() : fDirector(0,-1), fIndex(-1)
00031    {
00032    }
00033 
00034    //------------------------------------------------------------------------------------
00035    TFriendProxy::TFriendProxy(TBranchProxyDirector *director, TTree *main, Int_t index) :
00036       fDirector(0,-1), fIndex(index)
00037    {
00038       // Constructor.
00039 
00040       if (main) {
00041          TObject *obj = main->GetListOfFriends()->At(fIndex);
00042          TFriendElement *element = dynamic_cast<TFriendElement*>( obj );
00043          if (element) fDirector.SetTree(element->GetTree());
00044       }
00045       director->Attach(this);
00046    }
00047 
00048    //------------------------------------------------------------------------------------
00049    Long64_t TFriendProxy::GetReadEntry() const
00050    {
00051       // Return the entry number currently being looked at.
00052 
00053       return fDirector.GetReadEntry();
00054    }
00055 
00056    //------------------------------------------------------------------------------------
00057    void TFriendProxy::ResetReadEntry()
00058    {
00059       // Refresh the cached read entry number from the original tree.
00060 
00061       // The 2nd call to GetTree is to insure we get the 'local' tree's entry in the case of a
00062       // chain.
00063       if (fDirector.GetTree()) fDirector.SetReadEntry(fDirector.GetTree()->GetTree()->GetReadEntry());
00064    }
00065 
00066   //------------------------------------------------------------------------------------
00067    void TFriendProxy::Update(TTree *newmain)
00068    {
00069       // Update the address of the underlying tree.
00070 
00071       if (newmain) {
00072          TObject *obj = newmain->GetListOfFriends()->At(fIndex);
00073          TFriendElement *element = dynamic_cast<TFriendElement*>( obj );
00074          if (element) fDirector.SetTree(element->GetTree());
00075          else fDirector.SetTree(0);
00076       } else {
00077          fDirector.SetTree(0);
00078       }
00079    }
00080 }