added (and documented) wxSafeShowMessage, use it in wxLogFatalError instead of wxMessageBox

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15466 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/function.tex

@@ -180,6 +180,7 @@ the corresponding topic.
 \helpref{wxResourceRegisterBitmapData}{registerbitmapdata}\\
 \helpref{wxResourceRegisterIconData}{wxresourceregistericondata}\\
 \helpref{wxRmdir}{wxrmdir}\\
+\helpref{wxSafeShowMessage}{wxsafeshowmessage}\\
 \helpref{wxSafeYield}{wxsafeyield}\\
 \helpref{wxSetClipboardData}{wxsetclipboarddata}\\
 \helpref{wxSetCursor}{wxsetcursor}\\
@@ -3168,6 +3169,32 @@ trace masks.
 \item wxTraceOleCalls: trace OLE method calls (Win32 only)
 \end{itemize}
 
+\membersection{::wxSafeShowMessage}\label{wxsafeshowmessage}
+
+\func{void}{wxSafeShowMessage}{\param{const wxString\& }{title}, \param{const wxString\& }{text}}
+
+This function shows a message to the user in a safe way and should be safe to
+call even before the application has been initialized or if it is currently in
+some other strange state (for example, about to crash). Under Windows this
+function shows a message box using a native dialog instead of 
+\helpref{wxMessageBox}{wxmessagebox} (which might be unsafe to call), elsewhere
+it simply prints the message to the standard output using the title as prefix.
+
+\wxheading{Parameters}
+
+\docparam{title}{The title of the message box shown to the user or the prefix
+of the message string}
+
+\docparam{text}{The text to show to the user}
+
+\wxheading{See also}
+
+\helpref{wxLogFatalError}{wxlogfatalerror}
+
+\wxheading{Include files}
+
+<wx/log.h>
+
 \membersection{::wxSysErrorCode}\label{wxsyserrorcode}
 
 \func{unsigned long}{wxSysErrorCode}{\void}

include/wx/log.h

@@ -476,11 +476,13 @@ private:
 
 // return the last system error code
 WXDLLEXPORT unsigned long wxSysErrorCode();
+
 // return the error message for given (or last if 0) error code
 WXDLLEXPORT const wxChar* wxSysErrorMsg(unsigned long nErrCode = 0);
 
+// ----------------------------------------------------------------------------
 // define wxLog<level>
-// -------------------
+// ----------------------------------------------------------------------------
 
 #define DECLARE_LOG_FUNCTION(level)                                 \
 extern void WXDLLEXPORT wxVLog##level(const wxChar *szFormat,       \
@@ -559,6 +561,10 @@ DECLARE_LOG_FUNCTION2(SysError, long lErrCode);
     inline void wxLogTrace(const wxChar *, const wxChar *, ...) { }
 #endif // debug/!debug
 
+// wxLogFatalError helper: show the (fatal) error to the user in a safe way,
+// i.e. without using wxMessageBox() for example because it could crash
+extern void wxSafeShowMessage(const wxString& title, const wxString& text);
+
 // ----------------------------------------------------------------------------
 // debug only logging functions: use them with API name and error code
 // ----------------------------------------------------------------------------
@@ -588,4 +594,3 @@ DECLARE_LOG_FUNCTION2(SysError, long lErrCode);
 
 #endif  // _WX_LOG_H_
 
-// vi:sts=4:sw=4:et

src/common/log.cpp

@@ -159,17 +159,22 @@ IMPLEMENT_LOG_FUNCTION(Message)
 IMPLEMENT_LOG_FUNCTION(Info)
 IMPLEMENT_LOG_FUNCTION(Status)
 
+void wxSafeShowMessage(const wxString& title, const wxString& text)
+{
+#ifdef __WINDOWS__
+    ::MessageBox(NULL, text, title, MB_OK | MB_ICONSTOP);
+#else
+    wxFprintf(stderr, _T("%s: %s\n"), title.c_str(), text.c_str());
+#endif
+}
+
 // fatal errors can't be suppressed nor handled by the custom log target and
 // always terminate the program
 void wxVLogFatalError(const wxChar *szFormat, va_list argptr)
 {
     wxVsnprintf(s_szBuf, s_szBufSize, szFormat, argptr);
 
-#if wxUSE_GUI
+    wxSafeShowMessage(_T("Fatal Error"), s_szBuf);
-    wxMessageBox(s_szBuf, _("Fatal Error"), wxID_OK | wxICON_STOP);
-#else
-    wxFprintf(stderr, _("Fatal error: %s\n"), s_szBuf);
-#endif
 
     abort();
 }