//################# test.h ####################

#include <wx/wx.h>

DECLARE_EVENT_TYPE(MY_CUSTOM_EVENT_START, -1)

class CMyApp : public wxApp
{
public:
    void OnStart(wxCommandEvent& f_event);
    bool OnInit();

private:
    wxFrame* m_frame_p;
    wxStaticText* m_text_p;

    DECLARE_EVENT_TABLE()
};

//################# test.cpp ####################
#include <wx/evtloop.h>
#include <sstream>

#include "test.h"

IMPLEMENT_APP(CMyApp)

DEFINE_EVENT_TYPE(MY_CUSTOM_EVENT_START)

BEGIN_EVENT_TABLE(CMyApp, wxApp)
  EVT_COMMAND(wxID_ANY, MY_CUSTOM_EVENT_START, CMyApp::OnStart)
END_EVENT_TABLE()

bool
CMyApp::OnInit()
{
    wxCommandEvent event( MY_CUSTOM_EVENT_START );
    wxPostEvent(wxTheApp, event);

    m_frame_p = new wxFrame(NULL, wxID_ANY, wxT("Test application"));
    m_text_p = new wxStaticText(m_frame_p, wxID_ANY, wxT("Text"));

    return true;

}

void
CMyApp::OnStart(wxCommandEvent& f_event)
{
    m_frame_p->Show();

    int i = 0;
    wxEventLoop* l_loop = wxEventLoop::GetActive();

    while (true)
    {
        std::stringstream l_str;
        l_str << i++;
        m_text_p->SetLabel(wxConvertMB2WX(l_str.str().c_str()));

        while (l_loop->Pending())
        {
            l_loop->Dispatch();
        }
    }
}

// compile with:
// g++ `wx-config --cxxflags --libs` test.cpp -o test