class myWindow : public TGMainFrame {
public:
   myWindow();
   ~myWindow();

   void Start();
   void Continue();
   void Finish();
   void HandleTimer();

   enum EEntry {
      kStartButton,
      kContinueButton,
      kFinishButton
   };

private:
   TGTextButton* fStartButton{nullptr};
   TGTextButton* fContinueButton{nullptr};
   TGTextButton* fFinishButton{nullptr};
   TGTextButton* fEmitter{nullptr};
   TGLabel* fTestLabel{nullptr};
};

myWindow::myWindow()
{
   fTestLabel = new TGLabel(this, "test");
   AddFrame(fTestLabel, new TGLayoutHints(kLHintsTop | kLHintsExpandX, 0, 0, 0, 0));
   fStartButton = new TGTextButton(this, "Start", kStartButton);
   AddFrame(fStartButton, new TGLayoutHints(kLHintsTop | kLHintsExpandX, 0, 0, 0, 0));
   fStartButton->Connect("Clicked()", "myWindow", this, "Start()");
   Layout();
   MapSubwindows();
   MapWindow();
   Resize(200, GetDefaultHeight());
}

myWindow::~myWindow()
{
}

void myWindow::Start()
{
   fEmitter = fStartButton;
   TTimer::SingleShot(100, "myWindow", this, "HandleTimer()");
}

void myWindow::Continue()
{
   fEmitter = fContinueButton;
   TTimer::SingleShot(100, "myWindow", this, "HandleTimer()");
}

void myWindow::Finish()
{
   fFinishButton->Disconnect("Clicked()", this, "Finish()");
   CloseWindow();
}

void myWindow::HandleTimer()
{
   if (fEmitter == fStartButton) {
      fStartButton->Disconnect("Clicked()", this, "Start()");
      HideFrame(fStartButton);
      RemoveFrame(fStartButton);
      delete fStartButton;
      fStartButton = nullptr;
      fContinueButton = new TGTextButton(this, "Continue", kContinueButton);
      AddFrame(fContinueButton, new TGLayoutHints(kLHintsTop | kLHintsExpandX, 0, 0, 0, 0));
      fContinueButton->Connect("Clicked()", "myWindow", this, "Continue()");
   } else if (fEmitter == fContinueButton) {
      fContinueButton->Disconnect("Clicked()", this, "Continue()");
      HideFrame(fContinueButton);
      RemoveFrame(fContinueButton);
      delete fContinueButton;
      fContinueButton = nullptr;
      fFinishButton = new TGTextButton(this, "Finish", kFinishButton);
      AddFrame(fFinishButton, new TGLayoutHints(kLHintsTop | kLHintsExpandX, 0, 0, 0, 0));
      fFinishButton->Connect("Clicked()", "myWindow", this, "Finish()");
   }
   MapSubwindows();
   Layout();
}

void guitest()
{
   new myWindow;
}