Add wxPreferencesEditor class.

Implements native UI for preferences editing.  In particular, the API
handles the differences between modal (Windows) and non-modal (OS X) preferences windows and provides platform's native look.

Currently implemented natively for wxOSX/Cocoa, wxGTK and Windows (the latter is used as a fallback generic implementation as well).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73576 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/private/preferences.h

@@ -0,0 +1,45 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/private/preferences.h
+// Purpose:     wxPreferencesEditorImpl declaration.
+// Author:      Vaclav Slavik
+// Created:     2013-02-19
+// RCS-ID:      $Id$
+// Copyright:   (c) 2013 Vaclav Slavik <vslavik@fastmail.fm>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_PRIVATE_PREFERENCES_H_
+#define _WX_PRIVATE_PREFERENCES_H_
+
+#include "wx/preferences.h"
+
+#if wxUSE_TOOLBAR && defined(__WXOSX_COCOA__) && wxOSX_USE_NATIVE_TOOLBAR
+    #define wxHAS_PREF_EDITOR_NATIVE
+#endif
+
+#if defined(__WXOSX__) || defined(__WXGTK__)
+    #define wxHAS_PREF_EDITOR_MODELESS
+#endif
+
+// ----------------------------------------------------------------------------
+// wxPreferencesEditorImpl: defines wxPreferencesEditor implementation.
+// ----------------------------------------------------------------------------
+
+class wxPreferencesEditorImpl
+{
+public:
+    // This is implemented in a platform-specific way.
+    static wxPreferencesEditorImpl* Create();
+
+    // These methods simply mirror the public wxPreferencesEditor ones.
+    virtual void AddPage(wxPreferencesPage* page) = 0;
+    virtual void Show(wxWindow* parent) = 0;
+    virtual void Dismiss() = 0;
+
+    virtual ~wxPreferencesEditorImpl() {}
+
+protected:
+    wxPreferencesEditorImpl() {}
+};
+
+#endif // _WX_PRIVATE_PREFERENCES_H_