GUI Background Processes

ROOT
1

Hello,

I am writing a GUI that controls a power supply and I would like the read values to be updated in real time without affecting the user interface. I have so far been successful in updating the values in a set interval but only when the application is idle. The code is as follows…

gApplication->Connect(“HandleIdleTimer()”,“Class”,this,“DoHandleIdle()”);
gROOT->Idle(3,"");

I believe this is sending the idle signal to the application every 3 seconds however it only works when the main frame is in focus and the application is idle (obviously). I want to achieve the same effect without the application being idle and without the main frame in focus. Is there any way to do this?

Thanks,
Shawn

2

Hi,

You can create a timer in your Gui class, and update your values in the method YourGuiClass::HandleTimer(TTimer *t)
You can take a look at TSessionViewer.cxx to see a working example…

Cheers,
Bertrand.

3

Hi,

I’ve been trying to do something similar to this, using TSessionViewer as my example. I haven’t gotten it to work correctly yet. When I declare the TTimer with the TObject argument, an error message tells me that it’s unable to be called that way. When I drop the TObject argument, fTimer can’t be called from any other method within the class. Could someone let me know what I’m doing wrong? Thanks!

// barebones.C
#include  <TGClient.h>
#include  <TCanvas.h>
#include  <TF1.h>
#include  <TRandom.h>
#include  <TGButton.h>
#include  <TGFrame.h>
#include  <TRootEmbeddedCanvas.h>
#include  <RQ_OBJECT.h>
#include  <TTimer.h>

class MyMainFrame {
    RQ_OBJECT("MyMainFrame")
private:
    TGMainFrame *fMain;
  TRootEmbeddedCanvas *fEcanvas;
  TTimer *fTimer;
  //char *s;
public:
  MyMainFrame(const TGWindow *p,UInt_t w,UInt_t h);
  virtual ~MyMainFrame();
  void DoDraw();
  void EnableTimer();
  void DisableTimer();

};

//this function really just initializes things
MyMainFrame::MyMainFrame(const TGWindow *p,UInt_t w,UInt_t h) {
  
  fMain = new TGMainFrame(p,w,h);
  // Create a horizontal frame widget with buttons
  TGHorizontalFrame *hframe = new TGHorizontalFrame(fMain,200,200);

  TGTextButton *draw = new TGTextButton(hframe,"&Draw");
  draw->Connect("Clicked()","MyMainFrame",this,"EnableTimer()");
  hframe->AddFrame(draw, new TGLayoutHints(kLHintsCenterX,5,5,3,4));

  TGTextButton *exit = new TGTextButton(hframe,"&Exit","gApplication->Terminate(0)");
  hframe->AddFrame(exit, new TGLayoutHints(kLHintsCenterX,5,5,3,4));

  TGTextButton *start = new TGTextButton(hframe,"&Stop Monitor");
  hframe->AddFrame(start, new TGLayoutHints(kLHintsCenterX,5,5,3,4));
  start->Connect("Clicked()","MyMainFrame",this,"DisableTimer()");

  fMain->AddFrame(hframe, new TGLayoutHints(kLHintsCenterX,2,2,2,2));
  fMain->SetWindowName("Online Monitor");
  fMain->MapSubwindows();
  fMain->Resize(fMain->GetDefaultSize());
  fMain->MapWindow();
}

void MyMainFrame::DoDraw() {
  cout << fTimer << endl;

}

void MyMainFrame::EnableTimer()
{
  *fTimer = new TTimer(this, 1000);
  fTimer->Connect("Timeout()", "MyMainFrame", this, "DoDraw()");
  fTimer->Reset();
  // Enable timer.
  fTimer->TurnOn();

}

void MyMainFrame::DisableTimer()
{
  cout << fTimer << endl;
  fTimer->TurnOff();
}

MyMainFrame::~MyMainFrame() {
  fMain->Cleanup();
  delete fMain;
}

void barebones() {
  new MyMainFrame(gClient->GetRoot(),200,200);
}
4

Well, you already have the answer… Your class MyMainFrame doesn’t inherit from TObject…
See your modified (and working) code below:

[code]// barebones.C
#include <TGClient.h>
#include <TCanvas.h>
#include <TF1.h>
#include <TRandom.h>
#include <TGButton.h>
#include <TGFrame.h>
#include <TRootEmbeddedCanvas.h>
#include <RQ_OBJECT.h>
#include <TTimer.h>

class MyMainFrame : public TGMainFrame {

private:
TRootEmbeddedCanvas *fEcanvas;
TTimer *fTimer;
//char *s;
public:
MyMainFrame(const TGWindow *p,UInt_t w,UInt_t h);
virtual ~MyMainFrame();
void DoDraw();
void EnableTimer();
void DisableTimer();

};

//this function really just initializes things
MyMainFrame::MyMainFrame(const TGWindow *p,UInt_t w,UInt_t h) :
TGMainFrame(p, w, h)
{

// Create a horizontal frame widget with buttons
TGHorizontalFrame *hframe = new TGHorizontalFrame(this,200,200);

TGTextButton *draw = new TGTextButton(hframe,"&Draw");
draw->Connect(“Clicked()”,“MyMainFrame”,this,“EnableTimer()”);
hframe->AddFrame(draw, new TGLayoutHints(kLHintsCenterX,5,5,3,4));

TGTextButton *exit = new TGTextButton(hframe,"&Exit",“gApplication->Terminate(0)”);
hframe->AddFrame(exit, new TGLayoutHints(kLHintsCenterX,5,5,3,4));

TGTextButton *start = new TGTextButton(hframe,"&Stop Monitor");
hframe->AddFrame(start, new TGLayoutHints(kLHintsCenterX,5,5,3,4));
start->Connect(“Clicked()”,“MyMainFrame”,this,“DisableTimer()”);

AddFrame(hframe, new TGLayoutHints(kLHintsCenterX,2,2,2,2));
SetWindowName(“Online Monitor”);
MapSubwindows();
Resize(GetDefaultSize());
MapWindow();
}

void MyMainFrame::DoDraw()
{
static Int_t count = 0;
cout << ++count << endl;
}

void MyMainFrame::EnableTimer()
{
fTimer = new TTimer(this, 1000);
fTimer->Connect(“Timeout()”, “MyMainFrame”, this, “DoDraw()”);
fTimer->Reset();
// Enable timer.
fTimer->TurnOn();
}

void MyMainFrame::DisableTimer()
{
cout << fTimer << endl;
fTimer->TurnOff();
}

MyMainFrame::~MyMainFrame()
{
Cleanup();
}

void barebones()
{
new MyMainFrame(gClient->GetRoot(),200,200);
}

[/code]
Cheers,
Bertrand.

5

Thank you very much!