Dear Colleagues 

we have implemented in one of our tabs a button to call a function which saves a 
canvas to a pdf file with a time date stamp.

1) This works fine when there is only one histogram on the canvas and this code 
is MIDTBCTab.cpp (attached)

2) When the canvas is divided up into a 5x11 pads with 55 histograms and 
we want to save the _whole_ canvas with the whole picture (_not_ any individual 
pads) the code crashes  and no file is generated - the tab code is MIDTRCTab.cpp
and this is also attached 

I am wondering what is going on - is there anything obviously wrong ?

many thanks 

Farrukh

////////////////////////////////////////////////////////////////////////////////
//                                                                            //
// MIDTBCTab                                                                  //
//                                                                            //
// Begin_Html <!--
/*-->

<!--*/
// --> End_Html
//                                                                            //
//                                                                            //
////////////////////////////////////////////////////////////////////////////////

/* Generated header file containing necessary includes                        */
#include "generated/MIDTBCTabGeneratedIncludes.h"

////////////////////////////////////////////////////////////////////////////////
/*  This header was generated by ROMEBuilder. Manual changes above the        *
 * following line will be lost next time ROMEBuilder is executed.             */
/////////////////////////////////////----///////////////////////////////////////

#include "generated/MIDWindow.h"
#include "generated/MIDAnalyzer.h"
#include "tabs/MIDTBCTab.h"
#include "tasks/MIDTFillHistogram.h"
#include "TAxis.h"
#include "TLatex.h"
#include <TGClient.h>
#include <TCanvas.h>

#include <TRandom.h>
#include <TGButton.h>
#include <TGFrame.h>
#include <TRootEmbeddedCanvas.h>
#include <RQ_OBJECT.h>
#include<TString.h>
#include<TDatime.h>
// uncomment if you want to include headers of all folders
//#include "MIDAllFolders.h"


ClassImp(MIDTBCTab)

using namespace std;
//______________________________________________________________________________
void MIDTBCTab::Init()
{
  // Create style for this tab                                                 
  TStyle *orgStyle = gStyle;
  fStyle = new TStyle(*orgStyle); // copy the original style                   
  fStyle->SetOptTitle(1);
  fStyle->SetTitleOffset(0.18, "y");
  fStyle->SetPadGridX(1);
  fStyle->SetPadGridY(1);
  fStyle->SetPadTickX(1);
  fStyle->SetPadTickY(1);
  fStyle->SetFrameBorderSize(0);
  fStyle->SetFrameBorderMode(0);
  fStyle->SetFrameFillStyle(0);
  fStyle->SetTitleSize(0.06, "t");
  fStyle->SetStatH(0.09);
  fStyle->SetStatW(0.09);
  fStyle->cd();
  // Create a vertical frame containing buttons and canvas                     
  fVert = new TGVerticalFrame(this, (UInt_t) (700 * gAnalyzer->GetWindow()->GetWindowScale()), (UInt_t) (700 *gAnalyzer->GetWindow()->GetWindowScale()));

  // Create an embedded canvas and add to the main frame, centered in x and y                                                
  //  TString canvasname = "Sample Canvas";
  
  // set data member 
  fCanvasName =  new TString ("Sample Canvas");
  
  

  fCanvas = new TRootEmbeddedCanvas(fCanvasName->Data(), fVert, (UInt_t) (600 * gAnalyzer->GetWindow()->GetWindowScale()), (UInt_t) (600 * gAnalyzer->GetWindow()->GetWindowScale()));


  fCanvas->GetCanvas()->Divide(1,1);
  TLatex title;
  title.SetTextFont(12);                                                        
  title.SetTextSize(0.03);                                                      
  title.SetNDC(); 


  //Create save button                                                                                                      
  ULong_t green;
  gClient->GetColorByName("Green",green);
  fSaveCanvas = new TGTextButton(fVert, "SaveCanvas");
  fSaveCanvas->ChangeBackground(green);
  fSaveCanvas->Associate(this);
  fVert->AddFrame(fSaveCanvas, new TGLayoutHints(kLHintsCenterX, 5, 5, 3, 4));
                                               
                                                                                                               
                                  
                                                                                                                        /// Create "Update" button                                                    
  ULong_t yellow;
  gClient->GetColorByName("Yellow",yellow);                                            
  fBUpdate = new TGTextButton(fVert, "Update");
  fBUpdate->ChangeBackground(yellow);
  fBUpdate->Associate(this);

  //  fVert->AddFrame(fCanvas, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY, 4, 4, 4, 4));
  fVert->AddFrame(fBUpdate, new TGLayoutHints(kLHintsCenterX, 4, 4, 4, 4));
  // AddFrame(fVert, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY, 4, 4, 4, 4));



  //Create Exit button
  ULong_t red;
  gClient->GetColorByName("Red",red);                                    

  fExit = new TGTextButton(fVert,"&Exit", "gApplication->Terminate(0)");
  fExit->ChangeBackground(red);
  fExit->Associate(this);


  //  fVert->AddFrame(fCanvas, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY, 4, 4, 4, 4));
  
fVert->AddFrame(fExit, new TGLayoutHints(kLHintsCenterX, 5, 5, 3, 4));
                                                                                    
   



 fVert->AddFrame(fCanvas, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY, 5, 5, 3,  4)); 
 AddFrame(fVert, new TGLayoutHints(kLHintsExpandX | kLHintsExpandY, 4, 4, 4, 4)); 


  ConnectAll();

  orgStyle->cd();



}

//______________________________________________________________________________
void MIDTBCTab::EndInit()
{
}

//______________________________________________________________________________
void MIDTBCTab::EventHandler()
{
}

//______________________________________________________________________________
void MIDTBCTab::MenuClicked(TGPopupMenu * /* menu */, Long_t /* param */)
{
}

//______________________________________________________________________________
void MIDTBCTab::TabSelected()
{
}

//______________________________________________________________________________
void MIDTBCTab::TabUnSelected()
{
}
  // Save Canvas:
  // you'll need a function of the same signature in your .h -> also make sure that TString is included in your .h
  void MIDTBCTab::SaveCanvas() 
{

 
  TString * fileName = new TString (fCanvasName->Data());

    //replace all spaces in your canvas name 
    fileName->ReplaceAll(" ", "");
    
    //generate data and time stamp -> Recall you'll have to make sure TDatime is included 
    TDatime  dateTime; // time and date remain frozen when this function was called
    TString dateAsString = Form("%d", dateTime.GetDate());
    TString timeAsString = Form("%d", dateTime.GetTime());

    // append time date etc to canvas name

    (*fileName) += ".";
    (*fileName) += dateAsString;
    (*fileName) += ".";
    (*fileName) += timeAsString;
    (*fileName) += ".pdf"; // pdf for now maybe think about png and other options for user later ? 

    // debug
    //    cout << " This is the filename " << fileName->Data() << endl;

    // now print it and hope it works ....
    fCanvas->GetCanvas()->Print(fileName->Data());
    //cout << " Already attempted to print this file  " << fileName->Data() << endl;
}









void MIDTBCTab::Update()
{

  TLatex title;                                                                 
  title.SetTextFont(12);                                                        
  title.SetTextSize(0.03);                                                      
  title.SetNDC(); 

  TStyle *orgStyle = gStyle;
  fStyle->cd();

  TH2 *histo;

  for (Int_t i = 0; i < 1; i++) {
    fCanvas->GetCanvas()->cd(i + 1);
    histo = (TH2D *) gAnalyzer->GetFillHistogramTask()->Geth2_dt_tcpgotheaderAt(i);
    if (!histo) {
      cout << "Histo h2_dt_tcpgotheader not available." << endl;
    } else {

 


      histo->SetMarkerColor(1);
      histo->GetXaxis()->SetRangeUser(-20000,100000);
     
      histo->Draw("COLZ");

                                           
      title.SetTextColor(2);                                                        
                                                                                
                                      
                                                                                
                                                            
                                                                                
      title.SetTextColor(2); 
      title.DrawLatex(0.01,0.32,"tcp header #rightarrow");


      title.SetTextColor(3); 
                           
      title.DrawLatex(0.01,0.4,"tcp data  #rightarrow");                                 

      title.SetTextColor(4); 
      title.DrawLatex(0.01,0.48,"copy to GPU #rightarrow");                         
      title.SetTextColor(5); 
      title.DrawLatex(0.01,0.56,"GPU processing #rightarrow");                      

      title.SetTextColor(6); 
      title.DrawLatex(0.01,0.64,"MFE start #rightarrow");                           
      title.SetTextColor(7); 
      title.DrawLatex(0.01,0.72,"MFE stop #rightarrow");  


    }
  }

  fCanvas->GetCanvas()->cd(0);
  fCanvas->GetCanvas()->Modified();
  fCanvas->GetCanvas()->Update();

  orgStyle->cd();

  return;
}

//______________________________________________________________________________                                              
void MIDTBCTab::ConnectAll()
{
  fBUpdate->Connect("Pressed()", "MIDTBCTab", this, "Update()");
  fExit->Connect("Pressed()", "MIDTBCTab", this, "&Exit()");
  fSaveCanvas->Connect("Pressed()","MIDTBCTab", this, "SaveCanvas()");  
}
//______________________________________________________________________________                                         
void MIDTBCTab::DisconnectAll()
{
  if (fBUpdate) { fBUpdate->Disconnect(this); }
  if (fExit) { fExit->Disconnect(this); }
  if(fSaveCanvas) { fSaveCanvas->Disconnect(this);} 
}