Add wxUILocale with minimal functionality

Use it in the sample to show what (little) it can do right now.

src/msw/uilocale.cpp

@@ -0,0 +1,101 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        src/msw/uilocale.cpp
+// Purpose:     wxUILocale implementation for MSW
+// Author:      Vadim Zeitlin
+// Created:     2021-07-31
+// Copyright:   (c) 2021 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// for compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#if wxUSE_INTL
+
+#include "wx/private/uilocale.h"
+
+#include "wx/dynlib.h"
+
+#include "wx/msw/private.h"
+
+#ifndef LOCALE_SNAME
+#define LOCALE_SNAME 0x5c
+#endif
+
+// This function is defined in src/common/intl.cpp, just declare it here for
+// now before refactoring the code.
+wxString wxGetInfoFromLCID(LCID lcid, wxLocaleInfo index, wxLocaleCategory cat);
+
+// ============================================================================
+// implementation
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// wxUILocale implementation for MSW
+// ----------------------------------------------------------------------------
+
+// TODO-XP: Replace this with an implementation using GetLocaleInfoEx() when we
+// don't support XP any longer.
+class wxUILocaleImplLCID : public wxUILocaleImpl
+{
+public:
+    explicit wxUILocaleImplLCID(LCID lcid)
+        : m_lcid(lcid)
+    {
+    }
+
+    wxString GetName() const wxOVERRIDE
+    {
+        wxChar buf[256];
+        buf[0] = wxT('\0');
+
+        // Try using newer constant available since Vista which produces names
+        // more similar to the other platforms.
+        if ( wxGetWinVersion() >= wxWinVersion_Vista )
+        {
+            ::GetLocaleInfo(m_lcid, LOCALE_SNAME, buf, WXSIZEOF(buf));
+        }
+        else // TODO-XP: Drop this branch.
+        {
+            // This name constant is available under all systems, including
+            // pre-Vista ones.
+            ::GetLocaleInfo(m_lcid, LOCALE_SENGLANGUAGE, buf, WXSIZEOF(buf));
+        }
+
+        return buf;
+    }
+
+    wxString GetInfo(wxLocaleInfo index, wxLocaleCategory cat) const wxOVERRIDE
+    {
+        return wxGetInfoFromLCID(m_lcid, index, cat);
+    }
+
+private:
+    const LCID m_lcid;
+
+    wxDECLARE_NO_COPY_CLASS(wxUILocaleImplLCID);
+};
+
+/* static */
+wxUILocaleImpl* wxUILocaleImpl::CreateStdC()
+{
+    // There is no LCID for "C" locale, but US English is basically the same.
+    LCID lcid = MAKELCID(MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), SORT_DEFAULT);
+    return new wxUILocaleImplLCID(lcid);
+}
+
+/* static */
+wxUILocaleImpl* wxUILocaleImpl::CreateUserDefault()
+{
+    return new wxUILocaleImplLCID(LOCALE_USER_DEFAULT);
+}
+
+#endif // wxUSE_INTL