Blind implementation of YieldFor() for OSX/Cocoa, copied from OSX/Carbon

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58964 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/cocoa/evtloop.mm

@@ -30,6 +30,8 @@
     #include "wx/app.h"
 #endif // WX_PRECOMP
 
+#include "wx/log.h"
+
 #include "wx/osx/private.h"
 
 // ============================================================================
@@ -93,6 +95,43 @@ bool wxGUIEventLoop::Dispatch()
     return true;
 }
 
+bool wxGUIEventLoop::YieldFor(long eventsToProcess)
+{
+#if wxUSE_THREADS
+    // Yielding from a non-gui thread needs to bail out, otherwise we end up
+    // possibly sending events in the thread too.
+    if ( !wxThread::IsMain() )
+    {
+        return true;
+    }
+#endif // wxUSE_THREADS
+
+    m_isInsideYield = true;
+    m_eventsToProcessInsideYield = eventsToProcess;
+
+#if wxUSE_LOG
+    // disable log flushing from here because a call to wxYield() shouldn't
+    // normally result in message boxes popping up &c
+    wxLog::Suspend();
+#endif // wxUSE_LOG
+
+    // process all pending events:
+    while ( Pending() )
+        Dispatch();
+
+    // it's necessary to call ProcessIdle() to update the frames sizes which
+    // might have been changed (it also will update other things set from
+    // OnUpdateUI() which is a nice (and desired) side effect)
+    while ( ProcessIdle() ) {}
+
+#if wxUSE_LOG
+    wxLog::Resume();
+#endif // wxUSE_LOG
+    m_isInsideYield = false;
+
+    return true;
+}
+
 int wxGUIEventLoop::DispatchTimeout(unsigned long timeout)
 {
     wxMacAutoreleasePool autoreleasepool;