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CodeBlocksPortable/wxWidgets-3.0.5/samples/except/except.cpp

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/////////////////////////////////////////////////////////////////////////////
// Name: samples/except/except.cpp
// Purpose: shows how C++ exceptions can be used in wxWidgets
// Author: Vadim Zeitlin
// Modified by:
// Created: 2003-09-17
// Copyright: (c) 2003-2005 Vadim Zeitlin
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
// ============================================================================
// declarations
// ============================================================================
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"
#ifdef __BORLANDC__
#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" 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"
#include "wx/msgdlg.h"
#include "wx/icon.h"
#include "wx/thread.h"
#endif
// ----------------------------------------------------------------------------
// resources
// ----------------------------------------------------------------------------
// the application icon (under Windows and OS/2 it is in resources)
#ifndef wxHAS_IMAGES_IN_RESOURCES
#include "../sample.xpm"
#endif
// ----------------------------------------------------------------------------
// private functions
// ----------------------------------------------------------------------------
static void DoCrash()
{
char *p = 0;
strcpy(p, "Let's crash");
}
// ----------------------------------------------------------------------------
// private classes
// ----------------------------------------------------------------------------
// Define a new application type, each program should derive a class from wxApp
class MyApp : public wxApp
{
public:
// override base class virtuals
// ----------------------------
// program startup
virtual bool OnInit();
// 2nd-level exception handling: we get all the exceptions occurring in any
// event handler here
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();
// you can override this function to do something different (e.g. log the
// assert to file) whenever an assertion fails
virtual void OnAssertFailure(const wxChar *file,
int line,
const wxChar *func,
const wxChar *cond,
const wxChar *msg);
};
// Define a new frame type: this is going to be our main frame
class MyFrame : public wxFrame
{
public:
// ctor(s)
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);
void OnTrap(wxCommandEvent& event);
#if wxUSE_ON_FATAL_EXCEPTION
void OnHandleCrash(wxCommandEvent& event);
#endif
protected:
// 1st-level exception handling: we overload ProcessEvent() to be able to
// catch exceptions which occur in MyFrame methods here
virtual bool ProcessEvent(wxEvent& event);
// provoke assert in main or worker thread
//
// this is used to show how an assert failure message box looks like
void OnShowAssert(wxCommandEvent& event);
#if wxUSE_THREADS
void OnShowAssertInThread(wxCommandEvent& event);
#endif // wxUSE_THREADS
private:
// any class wishing to process wxWidgets events must use this macro
wxDECLARE_EVENT_TABLE();
};
// A simple dialog which has only some buttons to throw exceptions
class MyDialog : public wxDialog
{
public:
MyDialog(wxFrame *parent);
// event handlers
void OnThrowInt(wxCommandEvent& event);
void OnThrowObject(wxCommandEvent& event);
void OnCrash(wxCommandEvent& event);
private:
wxDECLARE_EVENT_TABLE();
};
// A trivial exception class
class MyException
{
public:
MyException(const wxString& msg) : m_msg(msg) { }
const wxChar *what() const { return m_msg.c_str(); }
private:
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 and menu items
Except_ThrowInt = wxID_HIGHEST,
Except_ThrowString,
Except_ThrowObject,
Except_ThrowUnhandled,
Except_Crash,
Except_Trap,
#if wxUSE_ON_FATAL_EXCEPTION
Except_HandleCrash,
#endif // wxUSE_ON_FATAL_EXCEPTION
Except_ShowAssert,
#if wxUSE_THREADS
Except_ShowAssertInThread,
#endif // wxUSE_THREADS
Except_Dialog,
Except_Quit = wxID_EXIT,
Except_About = wxID_ABOUT
};
// ----------------------------------------------------------------------------
// event tables and other macros for wxWidgets
// ----------------------------------------------------------------------------
// 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.
wxBEGIN_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)
EVT_MENU(Except_Trap, MyFrame::OnTrap)
#if wxUSE_ON_FATAL_EXCEPTION
EVT_MENU(Except_HandleCrash, MyFrame::OnHandleCrash)
#endif // wxUSE_ON_FATAL_EXCEPTION
EVT_MENU(Except_ShowAssert, MyFrame::OnShowAssert)
#if wxUSE_THREADS
EVT_MENU(Except_ShowAssertInThread, MyFrame::OnShowAssertInThread)
#endif // wxUSE_THREADS
wxEND_EVENT_TABLE()
wxBEGIN_EVENT_TABLE(MyDialog, wxDialog)
EVT_BUTTON(Except_ThrowInt, MyDialog::OnThrowInt)
EVT_BUTTON(Except_ThrowObject, MyDialog::OnThrowObject)
EVT_BUTTON(Except_Crash, MyDialog::OnCrash)
wxEND_EVENT_TABLE()
// 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
// not wxApp)
IMPLEMENT_APP(MyApp)
// ============================================================================
// MyApp implementation
// ============================================================================
// '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();
// and show it (the frames, unlike simple controls, are not shown when
// created initially)
frame->Show(true);
// success: wxApp::OnRun() will be called which will enter the main message
// loop and the application will run. If we returned false here, the
// application would exit immediately.
return true;
}
bool MyApp::OnExceptionInMainLoop()
{
try
{
throw;
}
catch ( int i )
{
wxLogWarning(wxT("Caught an int %d in MyApp."), i);
}
catch ( MyException& e )
{
wxLogWarning(wxT("Caught MyException(%s) in MyApp."), e.what());
}
catch ( ... )
{
throw;
}
return true;
}
void MyApp::OnUnhandledException()
{
// this shows how we may let some exception propagate uncaught
try
{
throw;
}
catch ( UnhandledException& )
{
throw;
}
catch ( ... )
{
wxMessageBox(wxT("Unhandled exception caught, program will terminate."),
wxT("wxExcept Sample"), wxOK | wxICON_ERROR);
}
}
void MyApp::OnFatalException()
{
wxMessageBox(wxT("Program has crashed and will terminate."),
wxT("wxExcept Sample"), wxOK | wxICON_ERROR);
}
void MyApp::OnAssertFailure(const wxChar *file,
int line,
const wxChar *func,
const wxChar *cond,
const wxChar *msg)
{
// take care to not show the message box from a worker thread, this doesn't
// work as it doesn't have any event loop
if ( !wxIsMainThread() ||
wxMessageBox
(
wxString::Format("An assert failed in %s().", func) +
"\n"
"Do you want to call the default assert handler?",
"wxExcept Sample",
wxYES_NO | wxICON_QUESTION
) == wxYES )
{
wxApp::OnAssertFailure(file, line, func, cond, msg);
}
}
// ============================================================================
// MyFrame implementation
// ============================================================================
// frame constructor
MyFrame::MyFrame()
: wxFrame(NULL, wxID_ANY, wxT("Except wxWidgets App"),
wxPoint(50, 50), wxSize(450, 340))
{
// set the frame icon
SetIcon(wxICON(sample));
#if wxUSE_MENUS
// create a menu bar
wxMenu *menuFile = new wxMenu;
menuFile->Append(Except_Dialog, wxT("Show &dialog\tCtrl-D"));
menuFile->AppendSeparator();
menuFile->Append(Except_ThrowInt, wxT("Throw an &int\tCtrl-I"));
menuFile->Append(Except_ThrowString, wxT("Throw a &string\tCtrl-S"));
menuFile->Append(Except_ThrowObject, wxT("Throw an &object\tCtrl-O"));
menuFile->Append(Except_ThrowUnhandled,
wxT("Throw &unhandled exception\tCtrl-U"));
menuFile->Append(Except_Crash, wxT("&Crash\tCtrl-C"));
menuFile->Append(Except_Trap, "&Trap\tCtrl-T",
"Break into the debugger (if one is running)");
menuFile->AppendSeparator();
#if wxUSE_ON_FATAL_EXCEPTION
menuFile->AppendCheckItem(Except_HandleCrash, wxT("&Handle crashes\tCtrl-H"));
menuFile->AppendSeparator();
#endif // wxUSE_ON_FATAL_EXCEPTION
menuFile->Append(Except_ShowAssert, wxT("Provoke &assert failure\tCtrl-A"));
#if wxUSE_THREADS
menuFile->Append(Except_ShowAssertInThread,
wxT("Assert failure in &thread\tShift-Ctrl-A"));
#endif // wxUSE_THREADS
menuFile->AppendSeparator();
menuFile->Append(Except_Quit, wxT("E&xit\tCtrl-Q"), wxT("Quit this program"));
wxMenu *helpMenu = new wxMenu;
helpMenu->Append(Except_About, wxT("&About\tF1"), wxT("Show about dialog"));
// now append the freshly created menu to the menu bar...
wxMenuBar *menuBar = new wxMenuBar();
menuBar->Append(menuFile, wxT("&File"));
menuBar->Append(helpMenu, wxT("&Help"));
// ... and attach this menu bar to the frame
SetMenuBar(menuBar);
#endif // wxUSE_MENUS
#if wxUSE_STATUSBAR && !defined(__WXWINCE__)
// create a status bar just for fun (by default with 1 pane only)
CreateStatusBar(2);
SetStatusText(wxT("Welcome to wxWidgets!"));
#endif // wxUSE_STATUSBAR
}
bool MyFrame::ProcessEvent(wxEvent& event)
{
try
{
return wxFrame::ProcessEvent(event);
}
catch ( const wxChar *msg )
{
wxLogMessage(wxT("Caught a string \"%s\" in MyFrame"), msg);
return true;
}
}
void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
{
// true is to force the frame to close
Close(true);
}
void MyFrame::OnDialog(wxCommandEvent& WXUNUSED(event))
{
try
{
MyDialog dlg(this);
dlg.ShowModal();
}
catch ( ... )
{
wxLogWarning(wxT("An exception in MyDialog"));
Destroy();
throw;
}
}
void MyFrame::OnThrowInt(wxCommandEvent& WXUNUSED(event))
{
throw -17;
}
void MyFrame::OnThrowString(wxCommandEvent& WXUNUSED(event))
{
throw wxT("string thrown from MyFrame");
}
void MyFrame::OnThrowObject(wxCommandEvent& WXUNUSED(event))
{
throw MyException(wxT("Exception thrown from MyFrame"));
}
void MyFrame::OnThrowUnhandled(wxCommandEvent& WXUNUSED(event))
{
throw UnhandledException();
}
void MyFrame::OnCrash(wxCommandEvent& WXUNUSED(event))
{
DoCrash();
}
void MyFrame::OnTrap(wxCommandEvent& WXUNUSED(event))
{
wxTrap();
}
#if wxUSE_ON_FATAL_EXCEPTION
void MyFrame::OnHandleCrash(wxCommandEvent& event)
{
wxHandleFatalExceptions(event.IsChecked());
}
#endif // wxUSE_ON_FATAL_EXCEPTION
void MyFrame::OnShowAssert(wxCommandEvent& WXUNUSED(event))
{
// provoke an assert from wxArrayString
wxArrayString arr;
arr[0];
}
#if wxUSE_THREADS
void MyFrame::OnShowAssertInThread(wxCommandEvent& WXUNUSED(event))
{
class AssertThread : public wxThread
{
public:
AssertThread()
: wxThread(wxTHREAD_JOINABLE)
{
}
protected:
virtual void *Entry()
{
wxFAIL_MSG("Test assert in another thread.");
return 0;
}
};
AssertThread thread;
thread.Create();
thread.Run();
thread.Wait();
}
#endif // wxUSE_THREADS
void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
wxString msg;
msg.Printf( wxT("This is the About dialog of the except sample.\n")
wxT("Welcome to %s"), wxVERSION_STRING);
wxMessageBox(msg, wxT("About Except"), wxOK | wxICON_INFORMATION, this);
}
// ============================================================================
// MyDialog implementation
// ============================================================================
MyDialog::MyDialog(wxFrame *parent)
: wxDialog(parent, wxID_ANY, wxString(wxT("Throw exception dialog")))
{
wxSizer *sizerTop = new wxBoxSizer(wxVERTICAL);
sizerTop->Add(new wxButton(this, Except_ThrowInt, wxT("Throw &int")),
0, wxCENTRE | wxALL, 5);
sizerTop->Add(new wxButton(this, Except_ThrowObject, wxT("Throw &object")),
0, wxCENTRE | wxALL, 5);
sizerTop->Add(new wxButton(this, Except_Crash, wxT("&Crash")),
0, wxCENTRE | wxALL, 5);
sizerTop->Add(new wxButton(this, wxID_CANCEL, wxT("&Cancel")),
0, wxCENTRE | wxALL, 5);
SetSizerAndFit(sizerTop);
}
void MyDialog::OnThrowInt(wxCommandEvent& WXUNUSED(event))
{
throw 17;
}
void MyDialog::OnThrowObject(wxCommandEvent& WXUNUSED(event))
{
throw MyException(wxT("Exception thrown from MyDialog"));
}
void MyDialog::OnCrash(wxCommandEvent& WXUNUSED(event))
{
DoCrash();
}