added wxEventLoop::DispatchTimeout()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57571 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/evtloop.cpp

@@ -99,6 +99,41 @@ bool wxMSWEventLoopBase::GetNextMessage(WXMSG* msg)
     return true;
 }
 
+int wxMSWEventLoopBase::GetNextMessageTimeout(WXMSG *msg, unsigned long timeout)
+{
+    // MsgWaitForMultipleObjects() won't notice any input which was already
+    // examined (e.g. using PeekMessage()) but not yet removed from the queue
+    // so we need to remove any immediately messages manually
+    //
+    // NB: using MsgWaitForMultipleObjectsEx() could simplify the code here but
+    //     it is not available in very old Windows versions
+    if ( !::PeekMessage(msg, 0, 0, 0, PM_REMOVE) )
+    {
+        // we use this function just in order to not block longer than the
+        // given timeout, so we don't pass any handles to it at all
+        if ( ::MsgWaitForMultipleObjects
+               (
+                0, NULL,
+                FALSE,
+                timeout,
+                QS_ALLINPUT
+               ) == WAIT_TIMEOUT )
+        {
+            return -1;
+        }
+
+        if ( !::PeekMessage(msg, 0, 0, 0, PM_REMOVE) )
+        {
+            wxFAIL_MSG( _T("PeekMessage() should have succeeded") );
+
+            return -1;
+        }
+    }
+
+    return msg->message != WM_QUIT;
+}
+
+
 #endif // wxUSE_BASE
 
 #if wxUSE_GUI
@@ -289,6 +324,18 @@ bool wxGUIEventLoop::Dispatch()
     return true;
 }
 
+int wxGUIEventLoop::DispatchTimeout(unsigned long timeout)
+{
+    MSG msg;
+    int rc = GetNextMessageTimeout(&msg, timeout);
+    if ( rc != 1 )
+        return rc;
+
+    ProcessMessage(&msg);
+
+    return 1;
+}
+
 void wxGUIEventLoop::OnNextIteration()
 {
 #if wxUSE_THREADS
@@ -318,22 +365,39 @@ void wxConsoleEventLoop::WakeUp()
 #endif
 }
 
+void wxConsoleEventLoop::ProcessMessage(WXMSG *msg)
+{
+    if ( msg->message == WM_TIMER )
+    {
+        TIMERPROC proc = (TIMERPROC)msg->lParam;
+        if ( proc )
+            (*proc)(NULL, 0, msg->wParam, 0);
+    }
+    else
+    {
+        ::DispatchMessage(msg);
+    }
+}
+
 bool wxConsoleEventLoop::Dispatch()
 {
     MSG msg;
     if ( !GetNextMessage(&msg) )
         return false;
 
-    if ( msg.message == WM_TIMER )
-    {
-        TIMERPROC proc = (TIMERPROC)msg.lParam;
-        if ( proc )
-            (*proc)(NULL, 0, msg.wParam, 0);
-    }
-    else
-    {
-        ::DispatchMessage(&msg);
-    }
+    ProcessMessage(&msg);
+
+    return !m_shouldExit;
+}
+
+int wxConsoleEventLoop::DispatchTimeout(unsigned long timeout)
+{
+    MSG msg;
+    int rc = GetNextMessageTimeout(&msg, timeout);
+    if ( rc != 1 )
+        return rc;
+
+    ProcessMessage(&msg);
 
     return !m_shouldExit;
 }