class TSlider: public TPad

TSlider

  A TSlider object is a specialized TPad including a TSliderBox object
The TSliderBox can be moved in the pad.
Slider drawing options include the possibility to change the slider
starting and ending positions or only one of them.

The current slider position can be retrieved via the functions
TSlider::GetMinimum and TSlider::GetMaximum
These two functions return numbers in the range [0,1].

if a method has been set (via SetMethod), the expression  is
executed via the interpreter when the button 1 is released.

if no method has been set, and an object is referenced (SetObject
has been called), while the slider is being moved/resized,
the object ExecuteEvent function is called.                         //

Example 1 using SetMethod    macro xyslider.C

{                                                                     
Example of macro featuring two sliders
TFile *f = new TFile("hsimple.root");
TH2F *hpxpy = (TH2F*)f->Get("hpxpy");
TCanvas *c1 = new TCanvas("c1");
TPad *pad = new TPad("pad","lego pad",0.1,0.1,0.98,0.98);
pad->SetFillColor(33);
pad->Draw();
pad->cd();
gStyle->SetFrameFillColor(42);
hpxpy->SetFillColor(46);
hpxpy->Draw("lego1");
c1->cd();

Create two sliders in main canvas. When button1
of the mouse will be released, action.C will be called
TSlider *xslider = new TSlider("xslider","x",0.1,0.02,0.98,0.08);
xslider->SetMethod(".x action.C");
TSlider *yslider = new TSlider("yslider","y",0.02,0.1,0.06,0.98);
yslider->SetMethod(".x action.C");
}                                                                     

macro action.C
{                                                                     
Int_t nx = hpxpy->GetXaxis()->GetNbins();
Int_t ny = hpxpy->GetYaxis()->GetNbins();
Int_t binxmin = nx*xslider->GetMinimum();
Int_t binxmax = nx*xslider->GetMaximum();
hpxpy->GetXaxis()->SetRange(binxmin,binxmax);
Int_t binymin = ny*yslider->GetMinimum();
Int_t binymax = ny*yslider->GetMaximum();
hpxpy->GetYaxis()->SetRange(binymin,binymax);
pad->cd();
hpxpy->Draw("lego1");
c1->Update();
}                                                                     
The canvas and the sliders created in the above macro are shown
in the picture below.

// /* */

Example 2 using SetObject    macro xyslider.C


Same example as above. Instead of SetMethod:
Myclass *obj = new Myclass(); // Myclass derived from TObject
xslider->SetObject(obj);
yslider->SetObject(obj);

When the slider will be changed, MyClass::ExecuteEvent will be
called with px=0 and py = 0