Timer.cpp

#include <wx/app.h>
#include <wx/button.h>
#include <wx/frame.h>
#include <wx/panel.h>
#include <wx/stattext.h>
#include <wx/timer.h>

namespace TimerExample {
  class Frame : public wxFrame {
  public:
    Frame() : wxFrame {nullptr, wxID_ANY, "Timer example"} {
      SetClientSize(230, 130);

      label->SetFont({48, wxFONTFAMILY_DEFAULT, wxFONTSTYLE_ITALIC, wxFONTWEIGHT_NORMAL, false, "Arial"});
      label->SetForegroundColour({30, 144, 255});

      button->Bind(wxEVT_BUTTON, [&](wxCommandEvent& event) {
        if (timer.IsRunning()) timer.Stop();
        else timer.Start(100);
        button->SetLabel(timer.IsRunning() ? "Stop" : "Start");
      });

      timer.Bind(wxEVT_TIMER, [&](wxTimerEvent& event) {
        label->SetLabelText(wxString::Format("%.1f", ++counter / 10.0));
      });
    }

  private:
    wxPanel* panel = new wxPanel {this};
    wxStaticText* label = new wxStaticText {panel, wxID_ANY, "0.0", {10, 10}};
    wxButton* button = new wxButton {panel, wxID_ANY, "Start", {10, 90}};
    wxTimer timer;
    int counter = 0;
  };

  class Application : public wxApp {
    bool OnInit() override {return (new Frame)->Show();}
  };
}

wxIMPLEMENT_APP(TimerExample::Application);