#include <TH1.h>
#include <TCanvas.h>
#include <TQObject.h>
#include "TROOT.h"

void exec3_mod()
{
   // Temporary work around the lack of automatic refresh of the list
   // when a script is reloaded.
   gROOT->GetListOfGlobalFunctions()->Delete();

   TH1F *h1 = new TH1F("h1","h1",100,-3,3);
   TH1F *h2 = new TH1F("h2","h2",100,-5,5);   
   h1->FillRandom("gaus",1000);
   h2->FillRandom("gaus",1000);   
   TCanvas *c1=new TCanvas("c1");
   c1->Divide(1,2);
   c1->cd(1);
   h1->Draw();
   c1->cd(2);
   h2->Draw();   
   c1->Update();
   c1->Connect("ProcessedEvent(Int_t,Int_t,Int_t,TObject*)", 0, 0,
               "exec3event(Int_t,Int_t,Int_t,TObject*)");
}

void exec3event(Int_t event, Int_t x, Int_t y, TObject *selected)
{
  if (event != 11) return;
  
  TCanvas *c = (TCanvas *) gTQSender;
  //  printf("Canvas %s: event=%d, x=%d, y=%d, selected=%s, selected name=%s\n", c->GetName(),
  //	 event, x, y, selected->IsA()->GetName(), selected->GetName());

  if (!selected->InheritsFrom(TPad::Class())) return;
  TPad *pad = (TPad*)selected;
  std::string pname = pad->GetName();
  
  TH1D* htmp = new TH1D;

  TObject *obj;
  TIter next(pad->GetListOfPrimitives());

  while ((obj = next())) {
    if (obj->InheritsFrom(TH1::Class())) {
      TH1* h = (TH1*)obj;
      htmp = (TH1D*)h->Clone();
    }
  }

  TCanvas *c2 = (TCanvas*)gROOT->GetListOfCanvases()->FindObject("c2");
  if(c2) delete c2->GetPrimitive("");
  else c2 = new TCanvas("c2","",700,500);
  c2->cd();
  htmp->Draw();
  c2->Update();
  
}