wxWidgets/samples/controls/controls.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        controls.cpp
// Purpose:     Controls wxWindows sample
// Author:      Robert Roebling
// Modified by:
// RCS-ID:      $Id$
// Copyright:   (c) Robert Roebling, Julian Smart
// Licence:   	wxWindows license
/////////////////////////////////////////////////////////////////////////////

#ifdef __GNUG__
#pragma implementation "controls.h"
#endif

// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif

#include "wx/notebook.h"
#include "wx/imaglist.h"

#if defined(__WXGTK__) || defined(__WXMOTIF__)
#include "mondrian.xpm"
#include "icons/choice.xpm"
#include "icons/combo.xpm"
#include "icons/list.xpm"
#include "icons/radio.xpm"
#include "icons/text.xpm"
#include "icons/gauge.xpm"
#endif

//----------------------------------------------------------------------
// class definitions
//----------------------------------------------------------------------

class MyApp: public wxApp
{ 
  public:
    bool OnInit(void);
};

class MyPanel: public wxPanel
{
  public:
 
    MyPanel(wxFrame *frame, int x, int y, int w, int h);
    virtual ~MyPanel();
    
    void OnSize( wxSizeEvent& event );
    void OnListBox( wxCommandEvent &event );
    void OnListBoxButtons( wxCommandEvent &event );
    void OnChoice( wxCommandEvent &event );
    void OnChoiceButtons( wxCommandEvent &event );
    void OnCombo( wxCommandEvent &event );
    void OnComboButtons( wxCommandEvent &event );
    void OnRadio( wxCommandEvent &event );
    void OnRadioButtons( wxCommandEvent &event );
    void OnSetFont( wxCommandEvent &event );
    void OnPageChanged( wxNotebookEvent &event );
    void OnSliderUpdate( wxCommandEvent &event );
    
    wxListBox   *m_listbox;
    wxChoice    *m_choice;
    wxComboBox  *m_combo;
    wxRadioBox  *m_radio;
    wxGauge     *m_gauge;
    wxSlider    *m_slider;
    wxButton    *m_fontButton;
    
    wxTextCtrl  *m_text;
    wxNotebook  *m_notebook;    
  
  DECLARE_EVENT_TABLE() 
};

class MyFrame: public wxFrame
{
  public:
  
    MyFrame(wxFrame *frame, char *title, int x, int y, int w, int h);
    
  public:
  
    void OnQuit(wxCommandEvent& event);
    void OnAbout(wxCommandEvent& event);
    bool OnClose(void) { return TRUE; }
    
  DECLARE_EVENT_TABLE()    
};

//----------------------------------------------------------------------
// main()
//----------------------------------------------------------------------

IMPLEMENT_APP	(MyApp)

//----------------------------------------------------------------------
// MyApp
//----------------------------------------------------------------------

const   int MINIMAL_QUIT   = 100;
const   int MINIMAL_TEXT   = 101;
const   int MINIMAL_ABOUT  = 102;

bool MyApp::OnInit(void)
{
  // Create the main frame window
  MyFrame *frame = new MyFrame((wxFrame *) NULL, (char *) "Controls wxWindows App", 50, 50, 530, 420 );
  
  // Give it an icon
#ifdef __WXMSW__
  frame->SetIcon(wxIcon("mondrian"));
#else
  frame->SetIcon(wxIcon( mondrian_xpm ));
#endif

  wxMenu *file_menu = new wxMenu;

  file_menu->Append(MINIMAL_ABOUT, "&About");
  file_menu->Append(MINIMAL_QUIT, "E&xit");
  wxMenuBar *menu_bar = new wxMenuBar;
  menu_bar->Append(file_menu, "&File");
  frame->SetMenuBar(menu_bar);

  frame->Show(TRUE);
  
  SetTopWindow(frame);

  return TRUE;
}

//----------------------------------------------------------------------
// MyPanel
//----------------------------------------------------------------------

const  ID_NOTEBOOK          = 1000;

const  ID_LISTBOX           = 130;
const  ID_LISTBOX_SEL_NUM   = 131;
const  ID_LISTBOX_SEL_STR   = 132;
const  ID_LISTBOX_CLEAR     = 133;
const  ID_LISTBOX_APPEND    = 134;
const  ID_LISTBOX_DELETE    = 135;
const  ID_LISTBOX_FONT      = 136;
const  ID_LISTBOX_ENABLE    = 137;

const  ID_CHOICE            = 120;
const  ID_CHOICE_SEL_NUM    = 121;
const  ID_CHOICE_SEL_STR    = 122;
const  ID_CHOICE_CLEAR      = 123;
const  ID_CHOICE_APPEND     = 124;
const  ID_CHOICE_DELETE     = 125;
const  ID_CHOICE_FONT       = 126;
const  ID_CHOICE_ENABLE     = 127;

const  ID_COMBO             = 140;
const  ID_COMBO_SEL_NUM     = 141;
const  ID_COMBO_SEL_STR     = 142;
const  ID_COMBO_CLEAR       = 143;
const  ID_COMBO_APPEND      = 144;
const  ID_COMBO_DELETE      = 145;
const  ID_COMBO_FONT        = 146;
const  ID_COMBO_ENABLE      = 147;

const  ID_TEXT              = 150;

const  ID_RADIOBOX          = 160;
const  ID_RADIOBOX_SEL_NUM  = 161;
const  ID_RADIOBOX_SEL_STR  = 162;
const  ID_RADIOBOX_FONT     = 163;
const  ID_RADIOBOX_ENABLE   = 164;

const  ID_SET_FONT          = 170;

const  ID_GAUGE             = 180;
const  ID_SLIDER            = 181;


BEGIN_EVENT_TABLE(MyPanel, wxPanel)
  EVT_SIZE      (                         MyPanel::OnSize)
  EVT_NOTEBOOK_PAGE_CHANGED(ID_NOTEBOOK,  MyPanel::OnPageChanged)  
  EVT_LISTBOX   (ID_LISTBOX,              MyPanel::OnListBox)
  EVT_BUTTON    (ID_LISTBOX_SEL_NUM,      MyPanel::OnListBoxButtons)
  EVT_BUTTON    (ID_LISTBOX_SEL_STR,      MyPanel::OnListBoxButtons)
  EVT_BUTTON    (ID_LISTBOX_CLEAR,        MyPanel::OnListBoxButtons)
  EVT_BUTTON    (ID_LISTBOX_APPEND,       MyPanel::OnListBoxButtons)
  EVT_BUTTON    (ID_LISTBOX_DELETE,       MyPanel::OnListBoxButtons)
  EVT_BUTTON    (ID_LISTBOX_FONT,         MyPanel::OnListBoxButtons)
  EVT_CHECKBOX  (ID_LISTBOX_ENABLE,       MyPanel::OnListBoxButtons)
  EVT_CHOICE    (ID_CHOICE,               MyPanel::OnChoice)
  EVT_BUTTON    (ID_CHOICE_SEL_NUM,       MyPanel::OnChoiceButtons)
  EVT_BUTTON    (ID_CHOICE_SEL_STR,       MyPanel::OnChoiceButtons)
  EVT_BUTTON    (ID_CHOICE_CLEAR,         MyPanel::OnChoiceButtons)
  EVT_BUTTON    (ID_CHOICE_APPEND,        MyPanel::OnChoiceButtons)
  EVT_BUTTON    (ID_CHOICE_DELETE,        MyPanel::OnChoiceButtons)
  EVT_BUTTON    (ID_CHOICE_FONT,          MyPanel::OnChoiceButtons)
  EVT_CHECKBOX  (ID_CHOICE_ENABLE,        MyPanel::OnChoiceButtons)
  EVT_CHOICE    (ID_COMBO,                MyPanel::OnCombo)
  EVT_BUTTON    (ID_COMBO_SEL_NUM,        MyPanel::OnComboButtons)
  EVT_BUTTON    (ID_COMBO_SEL_STR,        MyPanel::OnComboButtons)
  EVT_BUTTON    (ID_COMBO_CLEAR,          MyPanel::OnComboButtons)
  EVT_BUTTON    (ID_COMBO_APPEND,         MyPanel::OnComboButtons)
  EVT_BUTTON    (ID_COMBO_DELETE,         MyPanel::OnComboButtons)
  EVT_BUTTON    (ID_COMBO_FONT,           MyPanel::OnComboButtons)
  EVT_CHECKBOX  (ID_COMBO_ENABLE,         MyPanel::OnComboButtons)
  EVT_RADIOBOX  (ID_RADIOBOX,             MyPanel::OnRadio)
  EVT_BUTTON    (ID_RADIOBOX_SEL_NUM,     MyPanel::OnRadioButtons)
  EVT_BUTTON    (ID_RADIOBOX_SEL_STR,     MyPanel::OnRadioButtons)
  EVT_BUTTON    (ID_RADIOBOX_FONT,        MyPanel::OnRadioButtons)
  EVT_CHECKBOX  (ID_RADIOBOX_ENABLE,      MyPanel::OnRadioButtons)
  EVT_BUTTON    (ID_SET_FONT,             MyPanel::OnSetFont)
  EVT_SLIDER    (ID_SLIDER,               MyPanel::OnSliderUpdate)
END_EVENT_TABLE()

MyPanel::MyPanel( wxFrame *frame, int x, int y, int w, int h ) :
  wxPanel( frame, -1, wxPoint(x, y), wxSize(w, h) )
{
  SetBackgroundColour("cadet blue");

  m_text = new wxTextCtrl( this, -1, "This is the log window.\n", wxPoint(0,50), wxSize(100,50), wxTE_MULTILINE );
  m_text->SetBackgroundColour("wheat");
  
  m_notebook = new wxNotebook( this, ID_NOTEBOOK, wxPoint(0,0), wxSize(200,150) );
  
  wxString choices[] =
  {
    "This",
    "is one of my",
    "really",
    "wonderful",
    "examples.",
  };
  
  // image ids and names
  enum
  {
    Image_List, Image_Choice, Image_Combo, Image_Text, Image_Radio, Image_Gauge, Image_Max
  };
  
  // fill the image list
#ifdef __WXMSW__
  const char *aIconNames[] =
  {
    "list.xpm", "choice.xpm", "combo.xpm", "text.xpm", "radio.xpm", "gauge.txt"
  };
  
  wxASSERT( WXSIZEOF(aIconNames) == Image_Max ); // keep in sync

  wxString strIconDir = "icons/";
  
  wxImageList *imagelist = new wxImageList(32, 32);
  for ( size_t n = 0; n < Image_Max; n++ ) 
  {
    imagelist->Add(wxBitmap(strIconDir + aIconNames[n]));
  }
#else
  wxImageList *imagelist = new wxImageList(32, 32);
  
  imagelist-> Add( wxBitmap( list_xpm ));
  imagelist-> Add( wxBitmap( choice_xpm ));
  imagelist-> Add( wxBitmap( combo_xpm ));
  imagelist-> Add( wxBitmap( text_xpm ));
  imagelist-> Add( wxBitmap( radio_xpm ));
  imagelist-> Add( wxBitmap( gauge_xpm ));
#endif

  wxButton *button = (wxButton*)NULL;

  m_notebook->SetImageList(imagelist);
  m_notebook->SetBackgroundColour("cadet blue");

  wxPanel *panel = (wxPanel*) NULL;
  panel = new wxPanel(m_notebook);
  panel->SetBackgroundColour("cadet blue");
  panel->SetForegroundColour("blue");
  m_listbox = new wxListBox( panel, ID_LISTBOX, wxPoint(10,10), wxSize(120,70), 5, choices );
  m_listbox->SetBackgroundColour("wheat");
  (void)new wxButton( panel, ID_LISTBOX_SEL_NUM, "Select #2", wxPoint(180,30), wxSize(140,30) );
  (void)new wxButton( panel, ID_LISTBOX_SEL_STR, "Select 'This'", wxPoint(340,30), wxSize(140,30) );
  (void)new wxButton( panel, ID_LISTBOX_CLEAR, "Clear", wxPoint(180,80), wxSize(140,30) );
  (void)new wxButton( panel, ID_LISTBOX_APPEND, "Append 'Hi!'", wxPoint(340,80), wxSize(140,30) );
  (void)new wxButton( panel, ID_LISTBOX_DELETE, "Delete selected item", wxPoint(180,130), wxSize(140,30) );
  button = new wxButton( panel, ID_LISTBOX_FONT, "Set Italic font", wxPoint(340,130), wxSize(140,30) );
  button->SetForegroundColour( "red" );
  (void)new wxCheckBox( panel, ID_LISTBOX_ENABLE, "Disable", wxPoint(20,130), wxSize(140,30) );
  m_notebook->AddPage(panel, "wxList", FALSE, Image_List);
  
  panel = new wxPanel(m_notebook);
  panel->SetBackgroundColour("cadet blue");
  panel->SetForegroundColour("blue");
  m_choice = new wxChoice( panel, ID_CHOICE, wxPoint(10,10), wxSize(120,-1), 5, choices );
  m_choice->SetBackgroundColour("wheat");
  (void)new wxButton( panel, ID_CHOICE_SEL_NUM, "Select #2", wxPoint(180,30), wxSize(140,30) );
  (void)new wxButton( panel, ID_CHOICE_SEL_STR, "Select 'This'", wxPoint(340,30), wxSize(140,30) );
  (void)new wxButton( panel, ID_CHOICE_CLEAR, "Clear", wxPoint(180,80), wxSize(140,30) );
  (void)new wxButton( panel, ID_CHOICE_APPEND, "Append 'Hi!'", wxPoint(340,80), wxSize(140,30) );
  (void)new wxButton( panel, ID_CHOICE_DELETE, "Delete selected item", wxPoint(180,130), wxSize(140,30) );
  (void)new wxButton( panel, ID_CHOICE_FONT, "Set Italic font", wxPoint(340,130), wxSize(140,30) );
  (void)new wxCheckBox( panel, ID_CHOICE_ENABLE, "Disable", wxPoint(20,130), wxSize(140,30) );
  m_notebook->AddPage(panel, "wxChoice", FALSE, Image_Choice);
  
  panel = new wxPanel(m_notebook);
  panel->SetBackgroundColour("cadet blue");
  panel->SetForegroundColour("blue");
  m_combo = new wxComboBox( panel, ID_COMBO, "This", wxPoint(10,10), wxSize(120,-1), 5, choices );
  m_combo->SetBackgroundColour("wheat");
  (void)new wxButton( panel, ID_COMBO_SEL_NUM, "Select #2", wxPoint(180,30), wxSize(140,30) );
  (void)new wxButton( panel, ID_COMBO_SEL_STR, "Select 'This'", wxPoint(340,30), wxSize(140,30) );
  (void)new wxButton( panel, ID_COMBO_CLEAR, "Clear", wxPoint(180,80), wxSize(140,30) );
  (void)new wxButton( panel, ID_COMBO_APPEND, "Append 'Hi!'", wxPoint(340,80), wxSize(140,30) );
  (void)new wxButton( panel, ID_COMBO_DELETE, "Delete selected item", wxPoint(180,130), wxSize(140,30) );
  (void)new wxButton( panel, ID_COMBO_FONT, "Set Italic font", wxPoint(340,130), wxSize(140,30) );
  (void)new wxCheckBox( panel, ID_COMBO_ENABLE, "Disable", wxPoint(20,130), wxSize(140,30) );
  m_notebook->AddPage(panel, "wxComboBox", FALSE, Image_Combo);
  
  panel = new wxPanel(m_notebook);
  panel->SetBackgroundColour("cadet blue");
  panel->SetForegroundColour("blue");
  wxTextCtrl *tc = new wxTextCtrl( panel, ID_TEXT, "Write text here.", wxPoint(10,10), wxSize(350,28));
  (*tc) << " More text.";
  tc->SetBackgroundColour("wheat");
  tc = new wxTextCtrl( panel, ID_TEXT, "And here.", wxPoint(10,50), wxSize(350,160), wxTE_MULTILINE  );
  (*tc) << " More text.";
  tc->SetBackgroundColour("wheat");
  m_notebook->AddPage(panel, "wxTextCtrl" , FALSE, Image_Text);
  
  wxString choices2[] =
  {
    "Wonderful",
    "examples.",
  };
  
  panel = new wxPanel(m_notebook);
  panel->SetBackgroundColour("cadet blue");
  panel->SetForegroundColour("blue");
  m_radio = new wxRadioBox( panel, ID_RADIOBOX, "That", wxPoint(10,160), wxSize(-1,-1), 2, choices2, 1, wxRA_HORIZONTAL );
  m_radio->SetBackgroundColour("wheat");
  m_radio = new wxRadioBox( panel, ID_RADIOBOX, "This", wxPoint(10,10), wxSize(-1,-1), 5, choices, 1, wxRA_VERTICAL );
  m_radio->SetBackgroundColour("wheat");
  (void)new wxButton( panel, ID_RADIOBOX_SEL_NUM, "Select #2", wxPoint(180,30), wxSize(140,30) );
  (void)new wxButton( panel, ID_RADIOBOX_SEL_STR, "Select 'This'", wxPoint(180,80), wxSize(140,30) );
  (void)new wxButton( panel, ID_RADIOBOX_FONT, "Set Italic font", wxPoint(180,130), wxSize(140,30) );
  (void)new wxCheckBox( panel, ID_RADIOBOX_ENABLE, "Disable", wxPoint(340,130), wxSize(140,30) );
  m_fontButton = new wxButton( panel, ID_SET_FONT, "Set more Italic font", wxPoint(340,30), wxSize(160,30) );
  m_notebook->AddPage(panel, "wxRadioBox", FALSE, Image_Radio);
  
  panel = new wxPanel(m_notebook);
  panel->SetBackgroundColour("cadet blue");
  panel->SetForegroundColour("blue");
  (void)new wxStaticBox( panel, -1, "wxGauge and wxSlider", wxPoint(10,10), wxSize(180,130) );
  m_gauge = new wxGauge( panel, -1, 200, wxPoint(18,50), wxSize(155,-1) );
  m_gauge->SetBackgroundColour("wheat");
  m_slider = new wxSlider( panel, ID_SLIDER, 0, 0, 200, wxPoint(18,90), wxSize(155,-1) );
  m_slider->SetBackgroundColour("wheat");
  (void)new wxStaticBox( panel, -1, "Explanation", wxPoint(200,10), wxSize(290,130) );
  (void)new wxStaticText( panel, -1, 
    "In order see the gauge (aka progress bar)\n" 
    "control do something you have to drag the\n" 
    "handle of the slider to the right.\n"
    "\n"
    "This is also supposed to demonstrate how\n"
    "to use static controls.\n",
    wxPoint(208,25) );
  m_notebook->AddPage(panel, "wxGauge", FALSE, Image_Gauge);
}

void MyPanel::OnSize( wxSizeEvent& WXUNUSED(event) )
{
  int x = 0;
  int y = 0;
  GetClientSize( &x, &y );
  
  if (m_notebook) m_notebook->SetSize( 2, 2, x-4, y*2/3-4 );
  if (m_text) m_text->SetSize( 2, y*2/3+2, x-4, y/3-4 );
}

void MyPanel::OnPageChanged( wxNotebookEvent &event )
{
  *m_text << "Notebook selection is " << event.GetSelection() << "\n";
}

void MyPanel::OnListBox( wxCommandEvent &event )
{
  m_text->WriteText( "ListBox selection string is: " );
  m_text->WriteText( event.GetString() );
  m_text->WriteText( "\n" );
}

void MyPanel::OnListBoxButtons( wxCommandEvent &event )
{
  switch (event.GetId())
  {
    case ID_LISTBOX_ENABLE:
    {
      m_listbox->Enable( !((bool)event.GetInt()) );
      break;
    }
    case ID_LISTBOX_SEL_NUM:
    {
      m_listbox->SetSelection( 2 );
      break;
    }
    case ID_LISTBOX_SEL_STR:
    {
      m_listbox->SetStringSelection( "This" );
      break;
    }
    case ID_LISTBOX_CLEAR:
    {
      m_listbox->Clear();
      break;
    }
    case ID_LISTBOX_APPEND:
    {
      m_listbox->Append( "Hi!" );
      break;
    }
    case ID_LISTBOX_DELETE:
    {
      int idx = m_listbox->GetSelection();
      m_listbox->Delete( idx );
      break;
    }
    case ID_LISTBOX_FONT:
    {
      m_listbox->SetFont( *wxITALIC_FONT );
      break;
    }
  }
}

void MyPanel::OnChoice( wxCommandEvent &event )
{
  m_text->WriteText( "Choice selection string is: " );
  m_text->WriteText( event.GetString() );
  m_text->WriteText( "\n" );
}

void MyPanel::OnChoiceButtons( wxCommandEvent &event )
{
  switch (event.GetId())
  {
    case ID_CHOICE_ENABLE:
    {
      m_choice->Enable( !((bool)event.GetInt()) );
      break;
    }
    case ID_CHOICE_SEL_NUM:
    {
      m_choice->SetSelection( 2 );
      break;
    }
    case ID_CHOICE_SEL_STR:
    {
      m_choice->SetStringSelection( "This" );
      break;
    }
    case ID_CHOICE_CLEAR:
    {
      m_choice->Clear();
      break;
    }
    case ID_CHOICE_APPEND:
    {
      m_choice->Append( "Hi!" );
      break;
    }
    case ID_CHOICE_DELETE:
    {
      int idx = m_choice->GetSelection();
      m_choice->Delete( idx );
      break;
    }
    case ID_CHOICE_FONT:
    {
      m_choice->SetFont( *wxITALIC_FONT );
      break;
    }
  }
}

void MyPanel::OnCombo( wxCommandEvent &event )
{
  m_text->WriteText( "ComboBox selection string is: " );
  m_text->WriteText( event.GetString() );
  m_text->WriteText( "\n" );
}

void MyPanel::OnComboButtons( wxCommandEvent &event )
{
  switch (event.GetId())
  {
    case ID_COMBO_ENABLE:
    {
      m_combo->Enable( !((bool)event.GetInt()) );
      break;
    }
    case ID_COMBO_SEL_NUM:
    {
      m_combo->SetSelection( 2 );
      break;
    }
    case ID_COMBO_SEL_STR:
    {
      m_combo->SetStringSelection( "This" );
      break;
    }
    case ID_COMBO_CLEAR:
    {
      m_combo->Clear();
      break;
    }
    case ID_COMBO_APPEND:
    {
      m_combo->Append( "Hi!" );
      break;
    }
    case ID_COMBO_DELETE:
    {
      int idx = m_combo->GetSelection();
      m_combo->Delete( idx );
      break;
    }
    case ID_COMBO_FONT:
    {
      m_combo->SetFont( *wxITALIC_FONT );
      break;
    }
  }
}

void MyPanel::OnRadio( wxCommandEvent &event )
{
  m_text->WriteText( "RadioBox selection string is: " );
  m_text->WriteText( event.GetString() );
  m_text->WriteText( "\n" );
}

void MyPanel::OnRadioButtons( wxCommandEvent &event )
{
  switch (event.GetId())
  {
    case ID_RADIOBOX_ENABLE:
    {
      m_radio->Enable( !((bool)event.GetInt()) );
      break;
    }
    case ID_RADIOBOX_SEL_NUM:
    {
      m_radio->SetSelection( 2 );
      break;
    }
    case ID_RADIOBOX_SEL_STR:
    {
      m_radio->SetStringSelection( "This" );
      break;
    }
    case ID_RADIOBOX_FONT:
    {
      m_radio->SetFont( *wxITALIC_FONT );
      break;
    }
  }
}

void MyPanel::OnSetFont( wxCommandEvent &WXUNUSED(event) )
{
  m_fontButton->SetFont( *wxITALIC_FONT );
  m_text->SetFont( *wxITALIC_FONT );
}

void MyPanel::OnSliderUpdate( wxCommandEvent &WXUNUSED(event) )
{
  m_gauge->SetValue( m_slider->GetValue() );
}

MyPanel::~MyPanel()
{
  delete m_notebook->GetImageList();
}

//----------------------------------------------------------------------
// MyFrame
//----------------------------------------------------------------------

BEGIN_EVENT_TABLE(MyFrame, wxFrame)
    EVT_MENU(MINIMAL_QUIT,   MyFrame::OnQuit)
    EVT_MENU(MINIMAL_ABOUT,  MyFrame::OnAbout)
END_EVENT_TABLE()

MyFrame::MyFrame(wxFrame *frame, char *title, int x, int y, int w, int h):
  wxFrame(frame, -1, title, wxPoint(x, y), wxSize(w, h))
{
  (void)new MyPanel( this, 10, 10, 300, 100 );
}

void MyFrame::OnQuit (wxCommandEvent& WXUNUSED(event) )
{
  Close(TRUE);
}

void MyFrame::OnAbout( wxCommandEvent& WXUNUSED(event) )
{
  wxMessageDialog dialog(this, "This is a control sample", "About Controls", wxOK );
  dialog.ShowModal();
}