// @(#)root/histpainter:$Id: TPaletteAxis.cxx 37541 2010-12-11 10:50:58Z couet $
// Author: Rene Brun   15/11/2002

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#include "Riostream.h"
#include "TROOT.h"
#include "TPaletteAxis.h"
#include "TVirtualPad.h"
#include "TStyle.h"
#include "TMath.h"
#include "TView.h"
#include "TH1.h"
#include "TGaxis.h"

ClassImp(TPaletteAxis)


//______________________________________________________________________________
/* Begin_Html
<center><h2>The palette painting class</h2></center>

A <tt>TPaletteAxis</tt> object is used to display the color palette when
drawing 2-d histograms.
<p>
The <tt>TPaletteAxis</tt> is automatically created drawn when drawing a 2-D
histogram when the option "Z" is specified.
<p>
A <tt>TPaletteAxis</tt> object is added to the histogram list of functions and
can be retrieved doing:
<pre>
   TPaletteAxis *palette = (TPaletteAxis*)h->GetListOfFunctions()->FindObject("palette");
</pre>
then the pointer <tt>palette</tt> can be used to change the pallette attributes.
<p>
Because the palette is created at painting time only, one must issue a:
<pre>
   gPad->Update();
</pre>
before retrieving the palette pointer in order to create the palette. The following
macro gives an example.

End_Html
Begin_Macro(source)
{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *h2 = new TH2F("h2","Example of a resized palette ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      h2->Fill(px,5*py);
   }
   gStyle->SetPalette(1);
   h2->Draw("COLZ");
   gPad->Update();
   TPaletteAxis *palette = (TPaletteAxis*)h2->GetListOfFunctions()->FindObject("palette");
   palette->SetY2NDC(0.7);
   return c1;
}