// Mainframe macro generated from application: root
// By ROOT version 3.10/0102 on 2003-12-01 16:54:59

// Note: I stripped away a bunch of stuff thats irrelevant.  to this
// example:  I added two slots:
//   DoSlider() TGDoubleHSlider::PositionChanged() signal this 
//       is used to "pan" displayed 1D histo
//   UpdateSlider() responds to TPad::RangeAxisChanged() signal
//       this updates the slider to reflect change in x-axis
//       limits.  ALSO - it clips the displayed y-axis to a minimum
//       value of 0 - except it does'nt quite work - the user must
//       click on the canvas....

#if !defined( __CINT__) || defined (__MAKECINT__)

#ifndef ROOT_TGDoubleSlider
#include "TGDoubleSlider.h"
#endif
#ifndef ROOT_TGCanvas
#include "TGCanvas.h"
#endif
#ifndef ROOT_TRootEmbeddedCanvas
#include "TRootEmbeddedCanvas.h"
#endif
#ifndef ROOT_TCanvas
#include "TCanvas.h"
#endif

#include "TH1.h"
#include "TSystem.h"

#endif
TGDoubleHSlider *fSlider;
TH1F *ph;
void ctrls()
{

   // main frame
   TGMainFrame *frame2 = new TGMainFrame(gClient->GetRoot(),10,10,kMainFrame | kVerticalFrame);


   // composite frame
   TGCompositeFrame *frame35 = new TGCompositeFrame(frame2,805,626,kHorizontalFrame);


   // composite frame
   TGCompositeFrame *frame110 = new TGCompositeFrame(frame35,698,624,kVerticalFrame);

   // embedded canvas
   TRootEmbeddedCanvas *frame111 = new TRootEmbeddedCanvas(0,frame110,696,596);
   Int_t wframe111 = frame111->GetCanvasWindowId();
   TCanvas *ECanvas = new TCanvas("ECanvas", 10, 10, wframe111);
   frame111->AdoptCanvas(ECanvas);
   frame110->AddFrame(frame111, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY,1,1,1,1));

   ULong_t ucolor;        // will reflect user color changes
   gClient->GetColorByName("#bfbfbf",ucolor);
   fSlider = new TGDoubleHSlider(frame110,696,kDoubleScaleNo,-1,kHorizontalFrame,ucolor);
   fSlider->SetRange(0,700);
   frame110->AddFrame(fSlider, new TGLayoutHints(kLHintsExpandX,1,1,1,1));
   frame35->AddFrame(frame110, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY,1,1,1,1));
   frame2->AddFrame(frame35, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY,10,10,10,10));

   // This is the stuff I added to the SavePrimitive() stuff
   gPad->Connect("RangeAxisChanged()",0,0,"UpdateSlider()");
   fSlider->Connect("PositionChanged()",0,0,"DoSlider()");
   ph = new TH1F("ph","Test",100,-10.,10.);
   ph->FillRandom("gaus",100000);
   ph->Draw();

   frame2->SetWMSize(825,732);
   frame2->MapSubwindows();
   frame2->Resize(frame2->GetDefaultSize());
   frame2->MapWindow();
   frame2->Resize(825,732);
}  
//_____________________________________________________________________________
void UpdateSlider()
{
	// slot attached to gPad->RangeAxisChanged() signal:  re-set slider to match
	// TH1-derived x-axis limits and user limits.  Would be nice to add TF1-derived
	// object..

	// Also, if displayed histo does not derive from TH2, limit y-axis display only
	// non-negative values (ECN 450)
	TIter next(gPad->GetListOfPrimitives());
	TObject *obj;
	TAxis *paxis;
	while( obj = next())
	{
		if (obj->InheritsFrom("TH1"))
		{
			// following updates x-axis slider
			if (paxis = ((TH1 *)obj)->GetXaxis())
			{
				fSlider->SetRange(paxis->GetXmin(),paxis->GetXmax());
				fSlider->SetPosition(paxis->GetBinLowEdge(paxis->GetFirst()),
									 paxis->GetBinUpEdge(paxis->GetLast()));
			}

			// following clips y-axis at minimum=0 for TH1.  Note: user must click
			// on canvas to trigger the repaint
			if (!obj->InheritsFrom("TH2"))
			{
				TH1 *ph = (TH1 *)obj;
				if (ph->GetMinimum()<0. && ph->GetMinimum()!=-1111.) 
				{
					ph->SetMinimum(0.);
					gPad->Modified();
					gPad->Update();
					break;
				}
			}
		}
	}
}
//_____________________________________________________________________________
void DoSlider()
{
	// Handler for slider: use to set user range of displayed TH1-derived object.
	// Note: Would be nice to add TF1-derived things if no TH1-derived displayed
	TIter next(gPad->GetListOfPrimitives());
	TObject *obj;
	TAxis *paxis;
	while( obj = next())
	{
		if (obj->InheritsFrom("TH1"))
		{
			if (paxis = ((TH1 *)obj)->GetXaxis())
			{
				Float_t low,hi;
				fSlider->GetPosition(low,hi);
				paxis->SetRangeUser(low,hi);
				gSystem->ProcessEvents();
				gPad->Modified();
				gPad->Update();

			}
			break;
		}
	}
}