Refactor YieldFor() to avoid code duplication among the ports.

Don't repeat the same code in all the ports, move it to the common base class
and add a new virtual DoYieldFor() for the really port-specific code.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76061 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/cocoa/evtloop.h

@@ -24,10 +24,10 @@ public:
     virtual bool Dispatch();
     virtual int DispatchTimeout(unsigned long timeout);
     virtual void WakeUp() { }
-    virtual bool YieldFor(long eventsToProcess);
 
 protected:
     virtual int DoRun();
+    virtual void DoYieldFor(long eventsToProcess);
 
     int m_exitcode;
 

include/wx/evtloop.h

@@ -153,7 +153,12 @@ public:
     //          may result in calling the same event handler again), use
     //          with _extreme_ care or, better, don't use at all!
     bool Yield(bool onlyIfNeeded = false);
-    virtual bool YieldFor(long eventsToProcess) = 0;
+
+    // more selective version of Yield()
+    //
+    // notice that it is virtual for backwards-compatibility but new code
+    // should override DoYieldFor() and not YieldFor() itself
+    virtual bool YieldFor(long eventsToProcess);
 
     // returns true if the main thread is inside a Yield() call
     virtual bool IsYielding() const
@@ -182,6 +187,16 @@ protected:
     // real implementation of Run()
     virtual int DoRun() = 0;
 
+    // And the real, port-specific, implementation of YieldFor().
+    //
+    // The base class version is pure virtual to ensure that it is overridden
+    // in the derived classes but does have an implementation which processes
+    // pending events in wxApp if eventsToProcess allows it, and so should be
+    // called from the overridden version at an appropriate place (i.e. after
+    // processing the native events but before doing anything else that could
+    // be affected by pending events dispatching).
+    virtual void DoYieldFor(long eventsToProcess) = 0;
+
     // this function should be called before the event loop terminates, whether
     // this happens normally (because of Exit() call) or abnormally (because of
     // an exception thrown from inside the loop)
@@ -313,10 +328,10 @@ public:
         }
     }
     virtual void WakeUp() { }
-    virtual bool YieldFor(long eventsToProcess);
 
 protected:
     virtual int DoRun();
+    virtual void DoYieldFor(long eventsToProcess);
 
     // the pointer to the port specific implementation class
     wxEventLoopImpl *m_impl;

include/wx/gtk/evtloop.h

@@ -26,13 +26,13 @@ public:
     virtual bool Dispatch();
     virtual int DispatchTimeout(unsigned long timeout);
     virtual void WakeUp();
-    virtual bool YieldFor(long eventsToProcess);
 
     void StoreGdkEventForLaterProcessing(GdkEvent* ev)
         { m_arrGdkEvents.Add(ev); }
 
 protected:
     virtual int DoRun();
+    virtual void DoYieldFor(long eventsToProcess);
 
 private:
     // the exit code of this event loop

include/wx/msw/evtloop.h

@@ -54,10 +54,10 @@ public:
     virtual bool Dispatch();
     virtual int DispatchTimeout(unsigned long timeout);
     virtual void WakeUp();
-    virtual bool YieldFor(long eventsToProcess);
 
 protected:
     virtual void OnNextIteration();
+    virtual void DoYieldFor(long eventsToProcess);
 
 private:
     // check if the given window is a child of ms_winCritical (which must be

include/wx/msw/evtloopconsole.h

@@ -40,10 +40,12 @@ public:
     virtual bool Dispatch();
     virtual int DispatchTimeout(unsigned long timeout);
     virtual void WakeUp();
-    virtual bool YieldFor(long WXUNUSED(eventsToProcess)) { return true; }
 
     // Windows-specific function to process a single message
     virtual void ProcessMessage(WXMSG *msg);
+
+protected:
+    virtual void DoYieldFor(long eventsToProcess);
 };
 
 #endif // wxUSE_CONSOLE_EVENTLOOP

include/wx/osx/core/evtloop.h

@@ -42,8 +42,6 @@ public:
     // to it (can be called from non main thread)
     virtual void WakeUp();
 
-    virtual bool YieldFor(long eventsToProcess);
-
     bool ShouldProcessIdleEvents() const { return m_processIdleEvents ; }
     
 #if wxUSE_UIACTIONSIMULATOR
@@ -57,6 +55,8 @@ protected:
     // terminating when Exit() is called
     virtual int DoRun();
 
+    virtual void DoYieldFor(long eventsToProcess);
+
     void CommonModeObserverCallBack(CFRunLoopObserverRef observer, int activity);
     void DefaultModeObserverCallBack(CFRunLoopObserverRef observer, int activity);
 

include/wx/unix/evtloop.h

@@ -38,10 +38,10 @@ public:
     virtual int DispatchTimeout(unsigned long timeout);
     virtual void WakeUp();
     virtual bool IsOk() const { return m_dispatcher != NULL; }
-    virtual bool YieldFor(long WXUNUSED(eventsToProcess)) { return true; }
 
 protected:
     virtual void OnNextIteration();
+    virtual void DoYieldFor(long eventsToProcess);
 
 private:
     // pipe used for wake up messages: when a child thread wants to wake up