+/*
+ Creates a hidden window with supplied window proc registering the class for
+ it if necesssary (i.e. the first time only). Caller is responsible for
+ destroying the window and unregistering the class (note that this must be
+ done because wxWidgets may be used as a DLL and so may be loaded/unloaded
+ multiple times into/from the same process so we cna't rely on automatic
+ Windows class unregistration).
+
+ pclassname is a pointer to a caller stored classname, which must initially be
+ NULL. classname is the desired wndclass classname. If function succesfully
+ registers the class, pclassname will be set to classname.
+ */
+extern "C" WXDLLIMPEXP_BASE HWND
+wxCreateHiddenWindow(LPCTSTR *pclassname, LPCTSTR classname, WNDPROC wndproc)
+{
+ wxCHECK_MSG( classname && pclassname && wndproc, NULL,
+ _T("NULL parameter in wxCreateHiddenWindow") );
+
+ // register the class fi we need to first
+ if ( *pclassname == NULL )
+ {
+ WNDCLASS wndclass;
+ wxZeroMemory(wndclass);
+
+ wndclass.lpfnWndProc = wndproc;
+ wndclass.hInstance = wxGetInstance();
+ wndclass.lpszClassName = classname;
+
+ if ( !::RegisterClass(&wndclass) )
+ {
+ wxLogLastError(wxT("RegisterClass() in wxCreateHiddenWindow"));
+
+ return NULL;
+ }
+
+ *pclassname = classname;
+ }
+
+ // next create the window
+ HWND hwnd = ::CreateWindow
+ (
+ *pclassname,
+ NULL,
+ 0, 0, 0, 0,
+ 0,
+ (HWND) NULL,
+ (HMENU)NULL,
+ wxGetInstance(),
+ (LPVOID) NULL
+ );
+
+ if ( !hwnd )
+ {
+ wxLogLastError(wxT("CreateWindow() in wxCreateHiddenWindow"));
+ }
+
+ return hwnd;
+}
+