extracted common initialization/cleanup functions in common/init.cpp; standardized wxEntry()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@21518 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/init.h

@@ -0,0 +1,83 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/init.h
+// Purpose:     wxWindows initialization and finalization functions
+// Author:      Vadim Zeitlin
+// Modified by:
+// Created:     29.06.2003
+// RCS-ID:      $Id$
+// Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_INIT_H_
+#define _WX_INIT_H_
+
+#include "wx/wxchar.h"
+
+// ----------------------------------------------------------------------------
+// wxEntry helper functions which allow to have more fine grained control
+// ----------------------------------------------------------------------------
+
+// do common initialization, return true if ok (in this case wxEntryCleanup
+// must be called later), otherwise the program can't use wxWindows at all
+//
+// this function also creates wxTheApp as a side effect, if IMPLEMENT_APP
+// hadn't been used a dummy default application object is created
+//
+// note that the parameters may be modified
+extern bool WXDLLEXPORT wxEntryStart(int argc, wxChar **argv);
+
+// free the resources allocated by the library in wxEntryStart() and shut it
+// down (wxEntryStart() may be called again afterwards if necessary)
+extern void WXDLLEXPORT wxEntryCleanup();
+
+
+// ----------------------------------------------------------------------------
+// wxEntry: this function initializes the library, runs the main event loop
+//          and cleans it up
+// ----------------------------------------------------------------------------
+
+// note that other, platform-specific, overloads of wxEntry may exist as well
+// but this one always exists under all platforms
+//
+// returns the program exit code
+extern int WXDLLEXPORT wxEntry(int argc, wxChar **argv);
+
+
+// ----------------------------------------------------------------------------
+// Using the library without (explicit) application object: you may avoid using
+// DECLARE_APP and IMPLEMENT_APP macros and call the functions below instead at
+// the program startup and termination
+// ----------------------------------------------------------------------------
+
+// initialize the library (may be called as many times as needed, but each
+// call to wxInitialize() must be matched by wxUninitialize())
+extern bool WXDLLEXPORT wxInitialize(int argc = 0, wxChar **argv = NULL);
+
+// clean up -- the library can't be used any more after the last call to
+// wxUninitialize()
+extern void WXDLLEXPORT wxUninitialize();
+
+// create an object of this class on stack to initialize/cleanup the library
+// automatically
+class WXDLLEXPORT wxInitializer
+{
+public:
+    // initialize the library
+    wxInitializer() { m_ok = wxInitialize(); }
+
+    // has the initialization been successful? (explicit test)
+    bool IsOk() const { return m_ok; }
+
+    // has the initialization been successful? (implicit test)
+    operator bool() const { return m_ok; }
+
+    // dtor only does clean up if we initialized the library properly
+    ~wxInitializer() { if ( m_ok ) wxUninitialize(); }
+
+private:
+    bool m_ok;
+};
+
+#endif // _WX_INIT_H_
+