check in the 'selective yield' patch (see ticket #10320):

- implements YieldFor() with event filtering for wxMSW and wxGTK,
  adds TODO markers in other ports;
- replaces wxYield() in GTK's clipboard code with a wxTheApp->YieldFor() call, thus fixing possible reentrancies 
(and modifies clipboard sample to test synchronous IsSupported calls)
- replaces wxYieldIfNeeded() calls in wxProgressDialog with wxTheApp->YieldFor() calls, so that it processes only 
UI/user-input events, thus fixing the race condition visible in the "thread" sample
- documents the new functions


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58654 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/dfb/evtloop.cpp

@@ -204,6 +204,8 @@ wxIDirectFBEventBufferPtr wxGUIEventLoop::GetDirectFBEventBuffer()
 
 void wxGUIEventLoop::Yield()
 {
+    // TODO: implement event filtering using the eventsToProcess mask
+
     // process all pending events:
     while ( Pending() )
         Dispatch();