#include "TPad.h"
#include "TMath.h"
#include "TPaveLabel.h"
#include "TH2F.h"
#include "TString.h"

#include <iostream>
using namespace std;

//________________________________________________________________________

class MyTPaveLabel : public TPaveLabel
{
protected:
public:
	MyTPaveLabel(Double_t x1, Double_t y1,Double_t x2, Double_t  y2,
		const char *label, Option_t *option = "");
	void ConvertNDCtoPad();
	void Paint(Option_t *option);
	~MyTPaveLabel() {};
   ClassDef(MyTPaveLabel,1)  //PaveLabel. A Pave with a label 
};

ClassImp(MyTPaveLabel)

MyTPaveLabel::MyTPaveLabel(Double_t x1, Double_t y1,Double_t x2, Double_t  y2,
	const char *label, Option_t *option) :TPaveLabel(x1,y1,x2,y2,label,option)
{
	fOption = option;
	fOption.ToUpper();
}


//______________________________________________________________________________

void MyTPaveLabel::Paint(Option_t *option)
{
   // Paint this pavelabel with its current attributes.

   // Convert from NDC to pad coordinates
   // Note: dont use the one from TPave
   ConvertNDCtoPad();

   TPaveLabel::PaintPaveLabel(fX1, fY1, fX2, fY2,
    TPaveLabel::GetLabel(), strlen(option)?option:TPaveLabel::GetOption());
}
//______________________________________________________________________________

void MyTPaveLabel::ConvertNDCtoPad()
{
   // Convert pave coordinates from NDC to Pad coordinates.

   Double_t dpx  = gPad->GetX2() - gPad->GetX1();
   Double_t dpy  = gPad->GetY2() - gPad->GetY1();
   Double_t xp1  = gPad->GetX1();
   Double_t yp1  = gPad->GetY1();

   // Check if pave initialisation has been done.
   // This operation cannot take place in the Pave constructor because
   // the Pad range may not be known at this time.
   if (!fInit) {
      fInit = 1;
      if (fOption.Contains("NDC")) {
         fX1NDC = fX1;
         fY1NDC = fY1;
         fX2NDC = fX2;
         fY2NDC = fY2;
         fX1    = xp1 + fX1NDC*dpx;
         fY1    = yp1 + fY1NDC*dpy;
         fX2    = xp1 + fX2NDC*dpx;
         fY2    = yp1 + fY2NDC*dpy;
      } else {
         if (gPad->GetLogx()) {
            if (fX1 > 0) fX1 = TMath::Log10(fX1);
            if (fX2 > 0) fX2 = TMath::Log10(fX2);
         }
         if (gPad->GetLogy()) {
            if (fY1 > 0) fY1 = TMath::Log10(fY1);
            if (fY2 > 0) fY2 = TMath::Log10(fY2);
         }
         fX1NDC = (fX1-xp1)/dpx;
         fY1NDC = (fY1-yp1)/dpy;
         fX2NDC = (fX2-xp1)/dpx;
         fY2NDC = (fY2-yp1)/dpy;
      }
   } else {
      if (!fOption.Contains("FIX") || fOption.Contains("NDC")) {	//new
			fX1    = xp1 + fX1NDC*dpx;
			fY1    = yp1 + fY1NDC*dpy;
			fX2    = xp1 + fX2NDC*dpx;
			fY2    = yp1 + fY2NDC*dpy;
		} else {												//new
			// keep original lower left, keep size	//new
			Double_t sizeX= dpx * (fX2NDC-fX1NDC);	//new
			Double_t sizeY= dpy * (fY2NDC-fY1NDC);	//new
			fX2 = fX1 + sizeX;							//new
			fY2 = fY1 + sizeY;							//new
		}
   }
}

//_______________________________________________________________________

void testpl(){
   TH2F *hist = new TH2F("name", "title", 100, 0, 100, 100, 0, 100);
   hist->Draw();
   
   MyTPaveLabel* label_fixed = new MyTPaveLabel(40,50,60,60,"label_{fixed}", "FIX");
   label_fixed->Draw();
}