#include "TCanvas.h"
#include "TH1.h"
#include "TStyle.h"
#include "TPaveStats.h"
#include "TLatex.h"

void addCustomStat() {
    TCanvas *se = new TCanvas;
    se->SetFillStyle(0);
    se->SetFrameFillStyle(0);
    se->Print("addCustomStat.pdf[");
    TH1F *h1 = new TH1F("Gaus","Gaus",100,-3,3); 
    TH1F *h2 = new TH1F("Poly","Poly",100,-3,3); 
    h1->FillRandom("gaus",3000); 
    h2->FillRandom("landau",3000); 
    h1->Scale(1.0/h1->Integral());
    h2->Scale(1.0/h2->Integral());
    gStyle->SetOptStat(); // Enable the statistics box
    h1->Draw("hist");
    if(h1->GetMaximum()<h2->GetMaximum()) h1->GetYaxis()->SetRangeUser(0.0, h2->GetMaximum()*1.1);
    gPad->Update(); 
    TPaveStats *ps = (TPaveStats*)h1->FindObject("stats"); 
    ps->SetFillStyle(0);
    ps->SetX1NDC(1.0-gPad->GetRightMargin()-0.2); ps->SetX2NDC(1.0-gPad->GetRightMargin());
    ps->SetY1NDC(1.0-gPad->GetTopMargin()-0.2); ps->SetY2NDC(1.0-gPad->GetTopMargin());
    ps->SetBorderSize(0);
    ps->SetTextColor(kBlue);
    ps->SetLineColor(kBlue);
    TList *listOfLines = ps->GetListOfLines();

    TLatex *myt = new TLatex(0,0,"New Entry = 123.45"); 
    myt->SetTextFont(42);
    myt->SetTextSize(0.04);
    myt->SetTextColor(kRed);
    listOfLines->Add(myt);
    listOfLines->ls();

    h2->Draw("hist sames");
    h2->SetLineColor(kRed);
    gPad->Update(); 
    ps = (TPaveStats*)h2->FindObject("stats"); 
    ps->SetFillStyle(0);
    ps->SetX1NDC(1.0-gPad->GetRightMargin()-0.2); ps->SetX2NDC(1.0-gPad->GetRightMargin());
    ps->SetY1NDC(1.0-gPad->GetTopMargin()-0.4); ps->SetY2NDC(1.0-gPad->GetTopMargin()-0.2);
    ps->SetBorderSize(0);
    ps->SetTextColor(kRed);
    ps->SetLineColor(kRed);

    // Prevent the statistics box from being redrawn automatically
    //h->SetStats(0); 
    se->Modified(); 
    se->Update(); // Update the canvas again to display the changes
    se->Print("addCustomStat.pdf");
    se->Print("addCustomStat.pdf]");
}