#include <TApplication.h>
#include <TGClient.h>
#include <TGButton.h>
#include <TGFrame.h>
#include <TGLayout.h>
#include <TGWindow.h>
#include <TGLabel.h>
#include <TGNumberEntry.h>
#include <TString.h>

#include "Riostream.h"

void histo();

class MyMainFrame : public TGMainFrame {
 
private:
   
    TGLabel *fLabel515;
 
public:
  MyMainFrame(const TGWindow *p, UInt_t w, UInt_t h);
  virtual ~MyMainFrame();

void DoLabel(Int_t nlines) ;

  ClassDef(MyMainFrame, 0)

    };
                         
MyMainFrame::MyMainFrame(const TGWindow *p, UInt_t w, UInt_t h): TGMainFrame(p, w, h)

{

   TGFont *ufont;         // will reflect user font changes
   ufont = gClient->GetFont("-*-Arial-bold-r-*-*-24-*-*-*-*-*-*-*");

   TGGC   *uGC;           // will reflect user GC changes
   // graphics context changes
   GCValues_t vall515;
   vall515.fMask = kGCForeground | kGCBackground | kGCFillStyle | kGCFont | kGCGraphicsExposures;
   gClient->GetColorByName("#000000",vall515.fForeground);
   gClient->GetColorByName("#c0c0c0",vall515.fBackground);
   vall515.fFillStyle = kFillSolid;
   vall515.fFont = ufont->GetFontHandle();
   vall515.fGraphicsExposures = kFALSE;
   uGC = gClient->GetGC(&vall515, kTRUE);

   ULong_t ucolor;        // will reflect user color changes
   gClient->GetColorByName("#3399ff",ucolor);
   fLabel515 = new TGLabel( this,"1000",uGC->GetGC(),ufont->GetFontStruct(),kChildFrame,ucolor);
   fLabel515->SetTextJustify(36);
   fLabel515->SetMargins(0,0,0,0);
   fLabel515->SetWrapLength(-1);
    this->AddFrame(fLabel515, new TGLayoutHints(kLHintsLeft | kLHintsTop,2,2,2,2));
   fLabel515->MoveResize(16,8,192,72);

   this->SetMWMHints(kMWMDecorAll,
                        kMWMFuncAll,
                        kMWMInputModeless);
    this->MapSubwindows();

    this->Resize(this->GetDefaultSize());
    this->MapWindow();
    this->Resize(256,101);

histo();
}

void MyMainFrame::DoLabel(Int_t nlines)
{

cout<<"val ="<<nlines<<endl;
 fLabel515->SetText(nlines);

Layout();

}

void histo( )
{
   ifstream in;

   in.open("essai.dat");

   Float_t x;
   Int_t nlines = 0;

   TH1F *h1 = new TH1F("h1","x distribution",100,19000,21000);
   
   while (1) {
      in >> x ;
      if (!in.good()) break;
     
      h1->Fill(x);
     
      nlines++;
   }
   
   in.close();

//TCanvas *C1 = new TCanvas("1X ","1X",1);
h1 -> Draw();
nlines = 2345;
printf("In histo() nlines=%d\n",nlines);
MyMainFrame::DoLabel(nlines);
//above, the programme refuses to allow me to use "nlines" as argument. Why ?
}

void test1()
{
  new MyMainFrame(0,100,100);
           
}