samples/except/except.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        except.cpp
   3 // Purpose:     Except wxWindows sample
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx/wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 // for all others, include the necessary headers (this file is usually all you
  28 // need because it includes almost all "standard" wxWindows headers)
  29 #ifndef WX_PRECOMP
  30     #include "wx/log.h"
  31
  32     #include "wx/app.h"
  33     #include "wx/frame.h"
  34     #include "wx/dialog.h"
  35     #include "wx/menu.h"
  36
  37     #include "wx/button.h"
  38     #include "wx/sizer.h"
  39
  40     #include "wx/utils.h"               // for wxMessageBox
  41 #endif
  42
  43 // ----------------------------------------------------------------------------
  44 // resources
  45 // ----------------------------------------------------------------------------
  46
  47 // the application icon (under Windows and OS/2 it is in resources)
  48 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__) || defined(__WXX11__)
  49     #include "../sample.xpm"
  50 #endif
  51
  52 // ----------------------------------------------------------------------------
  53 // private classes
  54 // ----------------------------------------------------------------------------
  55
  56 // Define a new application type, each program should derive a class from wxApp
  57 class MyApp : public wxApp
  58 {
  59 public:
  60     // override base class virtuals
  61     // ----------------------------
  62
  63     // program startup
  64     virtual bool OnInit();
  65
  66     // 2nd-level exception handling: we get all the exceptions occuring in any
  67     // event handler here
  68     virtual void HandleEvent(wxEvtHandler *handler,
  69                              wxEventFunction func,
  70                              wxEvent& event) const;
  71
  72     // 3rd, and final, level exception handling: whenever an unhandled
  73     // exception is caught, this function is called
  74     virtual void OnUnhandledException();
  75 };
  76
  77 // Define a new frame type: this is going to be our main frame
  78 class MyFrame : public wxFrame
  79 {
  80 public:
  81     // ctor(s)
  82     MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size,
  83             long style = wxDEFAULT_FRAME_STYLE);
  84
  85     // event handlers (these functions should _not_ be virtual)
  86     void OnQuit(wxCommandEvent& event);
  87     void OnAbout(wxCommandEvent& event);
  88     void OnDialog(wxCommandEvent& event);
  89     void OnThrowString(wxCommandEvent& event);
  90
  91     // 1st-level exception handling: we overload ProcessEvent() to be able to
  92     // catch exceptions which occur in MyFrame methods here
  93     virtual bool ProcessEvent(wxEvent& event);
  94
  95 private:
  96     // any class wishing to process wxWindows events must use this macro
  97     DECLARE_EVENT_TABLE()
  98 };
  99
 100 // A simple dialog which has only some buttons to throw exceptions
 101 class MyDialog : public wxDialog
 102 {
 103 public:
 104     MyDialog(wxFrame *parent);
 105
 106     // event handlers
 107     void OnThrowInt(wxCommandEvent& event);
 108     void OnThrowObject(wxCommandEvent& event);
 109
 110 private:
 111     DECLARE_EVENT_TABLE()
 112 };
 113
 114 // A trivial exception class
 115 class MyException
 116 {
 117 public:
 118     MyException(const wxString& msg) : m_msg(msg) { }
 119
 120     const wxChar *what() const { return m_msg.c_str(); }
 121
 122 private:
 123     wxString m_msg;
 124 };
 125
 126 // ----------------------------------------------------------------------------
 127 // constants
 128 // ----------------------------------------------------------------------------
 129
 130 // IDs for the controls and the menu commands
 131 enum
 132 {
 133     // control ids
 134     Except_ThrowInt = 100,
 135     Except_ThrowObject,
 136
 137     // menu items
 138     Except_ThrowString = 200,
 139     Except_Dialog,
 140
 141     Except_Quit = wxID_EXIT,
 142     Except_About = wxID_ABOUT
 143 };
 144
 145 // ----------------------------------------------------------------------------
 146 // event tables and other macros for wxWindows
 147 // ----------------------------------------------------------------------------
 148
 149 // the event tables connect the wxWindows events with the functions (event
 150 // handlers) which process them. It can be also done at run-time, but for the
 151 // simple menu events like this the static method is much simpler.
 152 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 153     EVT_MENU(Except_Quit,  MyFrame::OnQuit)
 154     EVT_MENU(Except_About, MyFrame::OnAbout)
 155     EVT_MENU(Except_Dialog, MyFrame::OnDialog)
 156     EVT_MENU(Except_ThrowString, MyFrame::OnThrowString)
 157 END_EVENT_TABLE()
 158
 159 BEGIN_EVENT_TABLE(MyDialog, wxDialog)
 160     EVT_BUTTON(Except_ThrowInt, MyDialog::OnThrowInt)
 161     EVT_BUTTON(Except_ThrowObject, MyDialog::OnThrowObject)
 162 END_EVENT_TABLE()
 163
 164 // Create a new application object: this macro will allow wxWindows to create
 165 // the application object during program execution (it's better than using a
 166 // static object for many reasons) and also implements the accessor function
 167 // wxGetApp() which will return the reference of the right type (i.e. MyApp and
 168 // not wxApp)
 169 IMPLEMENT_APP(MyApp)
 170
 171 // ============================================================================
 172 // MyApp implementation
 173 // ============================================================================
 174
 175 // 'Main program' equivalent: the program execution "starts" here
 176 bool MyApp::OnInit()
 177 {
 178     // create the main application window
 179     MyFrame *frame = new MyFrame(_T("Except wxWindows App"),
 180                                  wxPoint(50, 50), wxSize(450, 340));
 181
 182     // and show it (the frames, unlike simple controls, are not shown when
 183     // created initially)
 184     frame->Show(true);
 185
 186     // success: wxApp::OnRun() will be called which will enter the main message
 187     // loop and the application will run. If we returned false here, the
 188     // application would exit immediately.
 189     return true;
 190 }
 191
 192 void
 193 MyApp::HandleEvent(wxEvtHandler *handler,
 194                    wxEventFunction func,
 195                    wxEvent& event) const
 196 {
 197     try
 198     {
 199         wxApp::HandleEvent(handler, func, event);
 200     }
 201     catch ( int i )
 202     {
 203         wxLogError(_T("Caught an int %d in MyApp."), i);
 204     }
 205 }
 206
 207 void MyApp::OnUnhandledException()
 208 {
 209     wxMessageBox(_T("Unhandled exception caught, program will terminate."),
 210                  _T("wxExcept Sample"), wxOK | wxICON_ERROR);
 211 }
 212
 213 // ============================================================================
 214 // MyFrame implementation
 215 // ============================================================================
 216
 217 // frame constructor
 218 MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size, long style)
 219        : wxFrame(NULL, -1, title, pos, size, style)
 220 {
 221     // set the frame icon
 222     SetIcon(wxICON(mondrian));
 223
 224 #if wxUSE_MENUS
 225     // create a menu bar
 226     wxMenu *menuFile = new wxMenu;
 227     menuFile->Append(Except_Dialog, _T("Show &dialog\tCtrl-D"));
 228     menuFile->Append(Except_ThrowString, _T("Throw a &string\tCtrl-S"));
 229     menuFile->AppendSeparator();
 230     menuFile->Append(Except_Quit, _T("E&xit\tCtrl-Q"), _T("Quit this program"));
 231
 232     wxMenu *helpMenu = new wxMenu;
 233     helpMenu->Append(Except_About, _T("&About...\tF1"), _T("Show about dialog"));
 234
 235     // now append the freshly created menu to the menu bar...
 236     wxMenuBar *menuBar = new wxMenuBar();
 237     menuBar->Append(menuFile, _T("&File"));
 238     menuBar->Append(helpMenu, _T("&Help"));
 239
 240     // ... and attach this menu bar to the frame
 241     SetMenuBar(menuBar);
 242 #endif // wxUSE_MENUS
 243
 244 #if wxUSE_STATUSBAR && !defined(__WXWINCE__)
 245     // create a status bar just for fun (by default with 1 pane only)
 246     CreateStatusBar(2);
 247     SetStatusText(_T("Welcome to wxWindows!"));
 248 #endif // wxUSE_STATUSBAR
 249 }
 250
 251 bool MyFrame::ProcessEvent(wxEvent& event)
 252 {
 253     try
 254     {
 255         return wxFrame::ProcessEvent(event);
 256     }
 257     catch ( const wxChar *msg )
 258     {
 259         wxLogMessage(_T("Caught a string \"%s\" in MyFrame"), msg);
 260
 261         return true;
 262     }
 263 }
 264
 265 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 266 {
 267     // true is to force the frame to close
 268     Close(true);
 269 }
 270
 271 void MyFrame::OnDialog(wxCommandEvent& WXUNUSED(event))
 272 {
 273     try
 274     {
 275         MyDialog dlg(this);
 276
 277         dlg.ShowModal();
 278     }
 279     catch ( ... )
 280     {
 281         Destroy();
 282         throw;
 283     }
 284 }
 285
 286 void MyFrame::OnThrowString(wxCommandEvent& WXUNUSED(event))
 287 {
 288     throw _T("some string");
 289 }
 290
 291 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 292 {
 293     wxString msg;
 294     msg.Printf( _T("This is the About dialog of the except sample.\n")
 295                 _T("Welcome to %s"), wxVERSION_STRING);
 296
 297     wxMessageBox(msg, _T("About Except"), wxOK | wxICON_INFORMATION, this);
 298 }
 299
 300 // ============================================================================
 301 // MyDialog implementation
 302 // ============================================================================
 303
 304 MyDialog::MyDialog(wxFrame *parent)
 305         : wxDialog(parent, -1, wxString(_T("Throw exception dialog")))
 306 {
 307     wxSizer *sizerTop = new wxBoxSizer(wxVERTICAL);
 308
 309     sizerTop->Add(new wxButton(this, Except_ThrowInt, _T("Throw &int")),
 310                   0, wxCENTRE | wxALL, 5);
 311     sizerTop->Add(new wxButton(this, Except_ThrowObject, _T("Throw &object")),
 312                   0, wxCENTRE | wxALL, 5);
 313     sizerTop->Add(new wxButton(this, wxID_CANCEL, _T("&Cancel")),
 314                   0, wxCENTRE | wxALL, 5);
 315
 316     SetSizer(sizerTop);
 317     sizerTop->Fit(this);
 318 }
 319
 320 void MyDialog::OnThrowInt(wxCommandEvent& WXUNUSED(event))
 321 {
 322     throw 17;
 323 }
 324
 325 void MyDialog::OnThrowObject(wxCommandEvent& WXUNUSED(event))
 326 {
 327     throw MyException(_T("Exception thrown from the dialog"));
 328 }
 329