#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:
	Int_t fInit;
	Int_t fAlign;
	TString fOption;
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)
{
	fInit = 0;
	fAlign = 11; 	// lower left corner
	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(TBox::fX1, TBox::fY1, TBox::fX2, TBox::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")) {
         TPave::fX1NDC = TBox::fX1;
         TPave::fY1NDC = fY1;
         TPave::fX2NDC = fX2;
         TPave::fY2NDC = fY2;
         TBox::fX1    = xp1 + TPave::fX1NDC*dpx;
         TBox::fY1    = yp1 + TPave::fY1NDC*dpy;
         TBox::fX2    = xp1 + TPave::fX2NDC*dpx;
         TBox::fY2    = yp1 + TPave::fY2NDC*dpy;
      } else {
         if (gPad->GetLogx()) {
            if (TBox::fX1 > 0) fX1 = TMath::Log10(fX1);
            if (TBox::fX2 > 0) fX2 = TMath::Log10(fX2);
         }
         if (gPad->GetLogy()) {
            if (TBox::fY1 > 0) fY1 = TMath::Log10(fY1);
            if (TBox::fY2 > 0) fY2 = TMath::Log10(fY2);
         }
         TPave::fX1NDC = (TBox::fX1-xp1)/dpx;
         TPave::fY1NDC = (TBox::fY1-yp1)/dpy;
         TPave::fX2NDC = (TBox::fX2-xp1)/dpx;
         TPave::fY2NDC = (TBox::fY2-yp1)/dpy;
      }
   } else {
      if (fOption.Contains("NDC")) {
			TBox::fX1    = xp1 + TPave::fX1NDC*dpx;
			TBox::fY1    = yp1 + TPave::fY1NDC*dpy;
			TBox::fX2    = xp1 + TPave::fX2NDC*dpx;
			TBox::fY2    = yp1 + TPave::fY2NDC*dpy;
		} else {
			// keep lower left corner, adjust size to original
			Double_t sizeX= dpx * (TPave::fX2NDC-TPave::fX1NDC);
			Double_t sizeY= dpy * (TPave::fY2NDC-TPave::fY1NDC);
			cout << TBox::fX1 << " " << TBox::fY1 << " " << sizeX
			<< " " << sizeY << endl;
//			if (fAlign == 11) {		// to be worked out
			TBox::fX2    = TBox::fX1 + sizeX;
			TBox::fY2    = TBox::fY1 + sizeY;
//		}
		}
   }
}

//_______________________________________________________________________

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}");
   label_fixed->Draw();
}