/////////////////////////////////////////////////////////////////////////////
-// Name: except.cpp
-// Purpose: Except wxWindows sample
-// Author: Julian Smart
+// Name: samples/except/except.cpp
+// Purpose: shows how C++ exceptions can be used in wxWidgets
+// Author: Vadim Zeitlin
// Modified by:
-// Created: 04/01/98
+// Created: 2003-09-17
// RCS-ID: $Id$
-// Copyright: (c) Julian Smart
+// Copyright: (c) 2003-2005 Vadim Zeitlin
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#pragma hdrstop
#endif
+#if !wxUSE_EXCEPTIONS
+ #error "This sample only works with wxUSE_EXCEPTIONS == 1"
+#endif // !wxUSE_EXCEPTIONS
+
// for all others, include the necessary headers (this file is usually all you
-// need because it includes almost all "standard" wxWindows headers)
+// need because it includes almost all "standard" wxWidgets headers)
#ifndef WX_PRECOMP
+ #include "wx/log.h"
+
#include "wx/app.h"
#include "wx/frame.h"
#include "wx/dialog.h"
+ #include "wx/menu.h"
#include "wx/button.h"
#include "wx/sizer.h"
- #include "wx/utils.h" // for wxMessageBox
+ #include "wx/utils.h"
+ #include "wx/msgdlg.h"
+ #include "wx/icon.h"
#endif
// ----------------------------------------------------------------------------
#include "../sample.xpm"
#endif
+// ----------------------------------------------------------------------------
+// private functions
+// ----------------------------------------------------------------------------
+
+static void DoCrash()
+{
+ char *p = 0;
+ strcpy(p, "Let's crash");
+}
+
// ----------------------------------------------------------------------------
// private classes
// ----------------------------------------------------------------------------
// program startup
virtual bool OnInit();
- // 2nd-level exception handling: we get all the exceptions occuring in any
+ // 2nd-level exception handling: we get all the exceptions occurring in any
// event handler here
- virtual void HandleEvent(wxEvtHandler *handler,
- wxEventFunction func,
- wxEvent& event) const;
+ virtual bool OnExceptionInMainLoop();
// 3rd, and final, level exception handling: whenever an unhandled
// exception is caught, this function is called
virtual void OnUnhandledException();
+
+ // and now for something different: this function is called in case of a
+ // crash (e.g. dereferencing null pointer, division by 0, ...)
+ virtual void OnFatalException();
+
+#ifdef __WXDEBUG__
+ // in debug mode, you can override this function to do something different
+ // (e.g. log the assert to file) whenever an assertion fails
+ virtual void OnAssert(const wxChar *file,
+ int line,
+ const wxChar *cond,
+ const wxChar *msg);
+#endif // __WXDEBUG__
};
// Define a new frame type: this is going to be our main frame
{
public:
// ctor(s)
- MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size,
- long style = wxDEFAULT_FRAME_STYLE);
+ MyFrame();
// event handlers (these functions should _not_ be virtual)
void OnQuit(wxCommandEvent& event);
void OnAbout(wxCommandEvent& event);
void OnDialog(wxCommandEvent& event);
+
+ void OnThrowInt(wxCommandEvent& event);
void OnThrowString(wxCommandEvent& event);
+ void OnThrowObject(wxCommandEvent& event);
+ void OnThrowUnhandled(wxCommandEvent& event);
+
+ void OnCrash(wxCommandEvent& event);
+#if wxUSE_ON_FATAL_EXCEPTION
+ void OnHandleCrash(wxCommandEvent& event);
+#endif
// 1st-level exception handling: we overload ProcessEvent() to be able to
// catch exceptions which occur in MyFrame methods here
virtual bool ProcessEvent(wxEvent& event);
+#ifdef __WXDEBUG__
+ // show how an assert failure message box looks like
+ void OnShowAssert(wxCommandEvent& event);
+#endif // __WXDEBUG__
+
private:
- // any class wishing to process wxWindows events must use this macro
+ // any class wishing to process wxWidgets events must use this macro
DECLARE_EVENT_TABLE()
};
// event handlers
void OnThrowInt(wxCommandEvent& event);
void OnThrowObject(wxCommandEvent& event);
+ void OnCrash(wxCommandEvent& event);
private:
DECLARE_EVENT_TABLE()
wxString m_msg;
};
+// Another exception class which just has to be different from anything else
+class UnhandledException
+{
+};
+
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
// IDs for the controls and the menu commands
enum
{
- // control ids
- Except_ThrowInt = 100,
+ // control ids and menu items
+ Except_ThrowInt = wxID_HIGHEST,
+ Except_ThrowString,
Except_ThrowObject,
-
- // menu items
- Except_ThrowString = 200,
+ Except_ThrowUnhandled,
+ Except_Crash,
+#if wxUSE_ON_FATAL_EXCEPTION
+ Except_HandleCrash,
+#endif // wxUSE_ON_FATAL_EXCEPTION
+#ifdef __WXDEBUG__
+ Except_ShowAssert,
+#endif // __WXDEBUG__
Except_Dialog,
Except_Quit = wxID_EXIT,
};
// ----------------------------------------------------------------------------
-// event tables and other macros for wxWindows
+// event tables and other macros for wxWidgets
// ----------------------------------------------------------------------------
-// the event tables connect the wxWindows events with the functions (event
+// the event tables connect the wxWidgets events with the functions (event
// handlers) which process them. It can be also done at run-time, but for the
// simple menu events like this the static method is much simpler.
BEGIN_EVENT_TABLE(MyFrame, wxFrame)
EVT_MENU(Except_Quit, MyFrame::OnQuit)
EVT_MENU(Except_About, MyFrame::OnAbout)
EVT_MENU(Except_Dialog, MyFrame::OnDialog)
+ EVT_MENU(Except_ThrowInt, MyFrame::OnThrowInt)
EVT_MENU(Except_ThrowString, MyFrame::OnThrowString)
+ EVT_MENU(Except_ThrowObject, MyFrame::OnThrowObject)
+ EVT_MENU(Except_ThrowUnhandled, MyFrame::OnThrowUnhandled)
+ EVT_MENU(Except_Crash, MyFrame::OnCrash)
+#if wxUSE_ON_FATAL_EXCEPTION
+ EVT_MENU(Except_HandleCrash, MyFrame::OnHandleCrash)
+#endif // wxUSE_ON_FATAL_EXCEPTION
+#ifdef __WXDEBUG__
+ EVT_MENU(Except_ShowAssert, MyFrame::OnShowAssert)
+#endif // __WXDEBUG__
END_EVENT_TABLE()
BEGIN_EVENT_TABLE(MyDialog, wxDialog)
EVT_BUTTON(Except_ThrowInt, MyDialog::OnThrowInt)
EVT_BUTTON(Except_ThrowObject, MyDialog::OnThrowObject)
+ EVT_BUTTON(Except_Crash, MyDialog::OnCrash)
END_EVENT_TABLE()
-// Create a new application object: this macro will allow wxWindows to create
+// Create a new application object: this macro will allow wxWidgets to create
// the application object during program execution (it's better than using a
// static object for many reasons) and also implements the accessor function
// wxGetApp() which will return the reference of the right type (i.e. MyApp and
// 'Main program' equivalent: the program execution "starts" here
bool MyApp::OnInit()
{
+ if ( !wxApp::OnInit() )
+ return false;
+
// create the main application window
- MyFrame *frame = new MyFrame(_T("Except wxWindows App"),
- wxPoint(50, 50), wxSize(450, 340));
+ MyFrame *frame = new MyFrame();
// and show it (the frames, unlike simple controls, are not shown when
// created initially)
return true;
}
-void
-MyApp::HandleEvent(wxEvtHandler *handler,
- wxEventFunction func,
- wxEvent& event) const
+bool MyApp::OnExceptionInMainLoop()
{
try
{
- wxApp::HandleEvent(handler, func, event);
+ throw;
}
catch ( int i )
{
- wxLogError(_T("Caught an int %d in MyApp."), i);
+ wxLogWarning(_T("Caught an int %d in MyApp."), i);
+ }
+ catch ( MyException& e )
+ {
+ wxLogWarning(_T("Caught MyException(%s) in MyApp."), e.what());
+ }
+ catch ( ... )
+ {
+ throw;
}
+
+ return true;
}
void MyApp::OnUnhandledException()
{
- wxMessageBox(_T("Unhandled exception caught, program will terminate."),
+ // this shows how we may let some exception propagate uncaught
+ try
+ {
+ throw;
+ }
+ catch ( UnhandledException& )
+ {
+ throw;
+ }
+ catch ( ... )
+ {
+ wxMessageBox(_T("Unhandled exception caught, program will terminate."),
+ _T("wxExcept Sample"), wxOK | wxICON_ERROR);
+ }
+}
+
+void MyApp::OnFatalException()
+{
+ wxMessageBox(_T("Program has crashed and will terminate."),
_T("wxExcept Sample"), wxOK | wxICON_ERROR);
}
+#ifdef __WXDEBUG__
+
+void MyApp::OnAssert(const wxChar *file,
+ int line,
+ const wxChar *cond,
+ const wxChar *msg)
+{
+ // we don't have anything special to do here
+ wxApp::OnAssert(file, line, cond, msg);
+}
+
+#endif // __WXDEBUG__
+
// ============================================================================
// MyFrame implementation
// ============================================================================
// frame constructor
-MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size, long style)
- : wxFrame(NULL, -1, title, pos, size, style)
+MyFrame::MyFrame()
+ : wxFrame(NULL, wxID_ANY, _T("Except wxWidgets App"),
+ wxPoint(50, 50), wxSize(450, 340))
{
// set the frame icon
- SetIcon(wxICON(mondrian));
+ SetIcon(wxICON(sample));
#if wxUSE_MENUS
// create a menu bar
wxMenu *menuFile = new wxMenu;
menuFile->Append(Except_Dialog, _T("Show &dialog\tCtrl-D"));
+ menuFile->AppendSeparator();
+ menuFile->Append(Except_ThrowInt, _T("Throw an &int\tCtrl-I"));
menuFile->Append(Except_ThrowString, _T("Throw a &string\tCtrl-S"));
+ menuFile->Append(Except_ThrowObject, _T("Throw an &object\tCtrl-O"));
+ menuFile->Append(Except_ThrowUnhandled,
+ _T("Throw &unhandled exception\tCtrl-U"));
+ menuFile->Append(Except_Crash, _T("&Crash\tCtrl-C"));
+ menuFile->AppendSeparator();
+#if wxUSE_ON_FATAL_EXCEPTION
+ menuFile->AppendCheckItem(Except_HandleCrash, _T("&Handle crashes\tCtrl-H"));
menuFile->AppendSeparator();
+#endif // wxUSE_ON_FATAL_EXCEPTION
+#ifdef __WXDEBUG__
+ menuFile->Append(Except_ShowAssert, _T("Provoke &assert failure\tCtrl-A"));
+ menuFile->AppendSeparator();
+#endif // __WXDEBUG__
menuFile->Append(Except_Quit, _T("E&xit\tCtrl-Q"), _T("Quit this program"));
wxMenu *helpMenu = new wxMenu;
#if wxUSE_STATUSBAR && !defined(__WXWINCE__)
// create a status bar just for fun (by default with 1 pane only)
CreateStatusBar(2);
- SetStatusText(_T("Welcome to wxWindows!"));
+ SetStatusText(_T("Welcome to wxWidgets!"));
#endif // wxUSE_STATUSBAR
}
void MyFrame::OnDialog(wxCommandEvent& WXUNUSED(event))
{
- MyDialog dlg(this);
+ try
+ {
+ MyDialog dlg(this);
- dlg.ShowModal();
+ dlg.ShowModal();
+ }
+ catch ( ... )
+ {
+ wxLogWarning(_T("An exception in MyDialog"));
+
+ Destroy();
+ throw;
+ }
+}
+
+void MyFrame::OnThrowInt(wxCommandEvent& WXUNUSED(event))
+{
+ throw -17;
}
void MyFrame::OnThrowString(wxCommandEvent& WXUNUSED(event))
{
- throw _T("some string");
+ throw _T("string thrown from MyFrame");
+}
+
+void MyFrame::OnThrowObject(wxCommandEvent& WXUNUSED(event))
+{
+ throw MyException(_T("Exception thrown from MyFrame"));
+}
+
+void MyFrame::OnThrowUnhandled(wxCommandEvent& WXUNUSED(event))
+{
+ throw UnhandledException();
+}
+
+void MyFrame::OnCrash(wxCommandEvent& WXUNUSED(event))
+{
+ DoCrash();
}
+#if wxUSE_ON_FATAL_EXCEPTION
+
+void MyFrame::OnHandleCrash(wxCommandEvent& event)
+{
+ wxHandleFatalExceptions(event.IsChecked());
+}
+
+#endif // wxUSE_ON_FATAL_EXCEPTION
+
+#ifdef __WXDEBUG__
+
+void MyFrame::OnShowAssert(wxCommandEvent& WXUNUSED(event))
+{
+ // provoke an assert from wxArrayString
+ wxArrayString arr;
+ arr[0];
+}
+
+#endif // __WXDEBUG__
+
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
wxString msg;
// ============================================================================
MyDialog::MyDialog(wxFrame *parent)
- : wxDialog(parent, -1, wxString(_T("Throw exception dialog")))
+ : wxDialog(parent, wxID_ANY, wxString(_T("Throw exception dialog")))
{
wxSizer *sizerTop = new wxBoxSizer(wxVERTICAL);
0, wxCENTRE | wxALL, 5);
sizerTop->Add(new wxButton(this, Except_ThrowObject, _T("Throw &object")),
0, wxCENTRE | wxALL, 5);
+ sizerTop->Add(new wxButton(this, Except_Crash, _T("&Crash")),
+ 0, wxCENTRE | wxALL, 5);
sizerTop->Add(new wxButton(this, wxID_CANCEL, _T("&Cancel")),
0, wxCENTRE | wxALL, 5);
void MyDialog::OnThrowObject(wxCommandEvent& WXUNUSED(event))
{
- throw MyException(_T("Exception thrown from the dialog"));
+ throw MyException(_T("Exception thrown from MyDialog"));
+}
+
+void MyDialog::OnCrash(wxCommandEvent& WXUNUSED(event))
+{
+ DoCrash();
}
projects / wxWidgets.git / blobdiff