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/common/appcmn.cpp

@@ -79,6 +79,7 @@ wxAppBase::wxAppBase()
     m_isActive = true;
 
     m_isInsideYield = false;
+    m_eventsToProcessInsideYield = wxEVT_CATEGORY_ALL;
 
     // We don't want to exit the app if the user code shows a dialog from its
     // OnInit() -- but this is what would happen if we set m_exitOnFrameDelete
@@ -325,6 +326,26 @@ void wxAppBase::SetActive(bool active, wxWindow * WXUNUSED(lastFocus))
     (void)ProcessEvent(event);
 }
 
+bool wxAppBase::IsEventAllowedInsideYield(wxEventCategory cat) const
+{
+    return m_eventsToProcessInsideYield & cat;
+}
+
+bool wxAppBase::SafeYield(wxWindow *win, bool onlyIfNeeded)
+{
+    wxWindowDisabler wd(win);
+
+    return Yield(onlyIfNeeded);
+}
+
+bool wxAppBase::SafeYieldFor(wxWindow *win, long eventsToProcess)
+{
+    wxWindowDisabler wd(win);
+
+    return YieldFor(eventsToProcess);
+}
+
+
 // ----------------------------------------------------------------------------
 // idle handling
 // ----------------------------------------------------------------------------