X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/556b8c1aab20985774000e1695e638539153edd7..e4de825ee6f3f991e2aa86159d6e3457afb6a8e0:/samples/except/except.cpp diff --git a/samples/except/except.cpp b/samples/except/except.cpp index 11972994af..5e487845d5 100644 --- a/samples/except/except.cpp +++ b/samples/except/except.cpp @@ -1,11 +1,11 @@ ///////////////////////////////////////////////////////////////////////////// -// 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 ///////////////////////////////////////////////////////////////////////////// @@ -24,17 +24,26 @@ #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 // ---------------------------------------------------------------------------- @@ -46,6 +55,16 @@ #include "../sample.xpm" #endif +// ---------------------------------------------------------------------------- +// private functions +// ---------------------------------------------------------------------------- + +static void DoCrash() +{ + char *p = 0; + strcpy(p, "Let's crash"); +} + // ---------------------------------------------------------------------------- // private classes // ---------------------------------------------------------------------------- @@ -60,15 +79,26 @@ public: // 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 @@ -76,21 +106,34 @@ class MyFrame : public wxFrame { 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() }; @@ -103,6 +146,7 @@ public: // event handlers void OnThrowInt(wxCommandEvent& event); void OnThrowObject(wxCommandEvent& event); + void OnCrash(wxCommandEvent& event); private: DECLARE_EVENT_TABLE() @@ -120,6 +164,11 @@ private: wxString m_msg; }; +// Another exception class which just has to be different from anything else +class UnhandledException +{ +}; + // ---------------------------------------------------------------------------- // constants // ---------------------------------------------------------------------------- @@ -127,12 +176,18 @@ private: // 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, @@ -140,25 +195,36 @@ enum }; // ---------------------------------------------------------------------------- -// 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 @@ -172,9 +238,11 @@ IMPLEMENT_APP(MyApp) // '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) @@ -186,44 +254,97 @@ bool MyApp::OnInit() 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; @@ -241,7 +362,7 @@ MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size, #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 } @@ -267,16 +388,66 @@ void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event)) 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; @@ -291,7 +462,7 @@ void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event)) // ============================================================================ 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); @@ -299,11 +470,12 @@ MyDialog::MyDialog(wxFrame *parent) 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); - SetSizer(sizerTop); - sizerTop->Fit(this); + SetSizerAndFit(sizerTop); } void MyDialog::OnThrowInt(wxCommandEvent& WXUNUSED(event)) @@ -313,6 +485,11 @@ void MyDialog::OnThrowInt(wxCommandEvent& WXUNUSED(event)) 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(); }