TVirtualHistPainter.cxx

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// @(#)root/hist:$Id$
// Author: Rene Brun   30/08/99
/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
#include "TROOT.h"
#include "TVirtualHistPainter.h"
#include "TPluginManager.h"
 
TClass *TVirtualHistPainter::fgPainter = nullptr;
 
 
 
/** \class TVirtualHistPainter
 \ingroup Histpainter
 Abstract interface to a histogram painter
*/
 
 
////////////////////////////////////////////////////////////////////////////////
/// Static function returning a pointer to the current histogram painter.
/// The painter will paint the specified obj. If the histogram painter
/// does not exist a default painter is created.
 
TVirtualHistPainter *TVirtualHistPainter::HistPainter(TH1 *obj)
{
   // if no painter set yet, create a default painter via the PluginManager
   if (!fgPainter) {
      TPluginHandler *h;
      if ((h = gROOT->GetPluginManager()->FindHandler("TVirtualHistPainter"))) {
         if (h->LoadPlugin() == -1)
            return nullptr;
         TVirtualHistPainter::SetPainter(h->GetClass());
         if (!fgPainter) return nullptr;
      } else {
         // fgPainter is still null
         return nullptr;
      }
   }
 
   //create an instance of the histogram painter
   TVirtualHistPainter *p = (TVirtualHistPainter*)fgPainter->New();
   if (p) p->SetHistogram(obj);
   return p;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Static function to set an alternative histogram painter.
 
void TVirtualHistPainter::SetPainter(const char *painter)
{
   fgPainter = TClass::GetClass(painter);
}