made wxApp::argv an object convertible to either char** or wchar_t** for better compatibility with the existing ANSI code

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@49877 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/cmdargs.h

@@ -0,0 +1,128 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/cmdargs.h
+// Purpose:     declaration of wxCmdLineArgsArray helper class
+// Author:      Vadim Zeitlin
+// Created:     2007-11-12
+// RCS-ID:      $Id$
+// Copyright:   (c) 2007 Vadim Zeitlin <vadim@wxwindows.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_CMDARGS_H_
+#define _WX_CMDARGS_H_
+
+#include "wx/arrstr.h"
+
+// ----------------------------------------------------------------------------
+// wxCmdLineArgsArray: helper class used by wxApp::argv
+// ----------------------------------------------------------------------------
+
+#if wxUSE_UNICODE
+
+// this class is used instead of either "char **" or "wchar_t **" (neither of
+// which would be backwards compatible with all the existing code) for argv
+// field of wxApp
+//
+// as it's used for compatibility, it tries to look as much as traditional
+// (char **) argv as possible, in particular it provides implicit conversions
+// to "char **" and also array-like operator[]
+class wxCmdLineArgsArray
+{
+public:
+    wxCmdLineArgsArray() { m_argsA = NULL; m_argsW = NULL; }
+
+    template <typename T>
+    wxCmdLineArgsArray& operator=(T **argv)
+    {
+        FreeArgs();
+
+        m_args.clear();
+
+        if ( argv )
+        {
+            while ( *argv )
+                m_args.push_back(*argv++);
+        }
+
+        return *this;
+    }
+
+    operator char**() const
+    {
+        if ( !m_argsA )
+        {
+            const size_t count = m_args.size();
+            m_argsA = new char *[count];
+            for ( size_t n = 0; n < count; n++ )
+                m_argsA[n] = wxStrdup(m_args[n].ToAscii());
+        }
+
+        return m_argsA;
+    }
+
+    operator wchar_t**() const
+    {
+        if ( !m_argsW )
+        {
+            const size_t count = m_args.size();
+            m_argsW = new wchar_t *[count];
+            for ( size_t n = 0; n < count; n++ )
+                m_argsW[n] = wxStrdup(m_args[n].wc_str());
+        }
+
+        return m_argsW;
+    }
+
+    // existing code does checks like "if ( argv )" and we want it to continue
+    // to compile, so provide this conversion even if it is pretty dangerous
+    operator bool() const
+    {
+        return !m_args.empty();
+    }
+
+    wxString operator[](size_t n) const
+    {
+        return m_args[n];
+    }
+
+    // this is the only method of this class which doesn't exist solely for
+    // compatibility purposes: it allows to access the arguments as a
+    // convenient array of wxStrings
+    const wxArrayString& GetArguments() const { return m_args; }
+
+    ~wxCmdLineArgsArray()
+    {
+        FreeArgs();
+    }
+
+private:
+    template <typename T>
+    void Free(T **args)
+    {
+        if ( !args )
+            return;
+
+        const size_t count = m_args.size();
+        for ( size_t n = 0; n < count; n++ )
+            free(args[n]);
+
+        delete [] args;
+    }
+
+    void FreeArgs()
+    {
+        Free(m_argsA);
+        Free(m_argsW);
+    }
+
+    wxArrayString m_args;
+    mutable char **m_argsA;
+    mutable wchar_t **m_argsW;
+
+    DECLARE_NO_COPY_CLASS(wxCmdLineArgsArray)
+};
+
+#endif // wxUSE_UNICODE
+
+#endif // _WX_CMDARGS_H_
+