more compilation fixes for VC6 (#9492)

[wxWidgets.git] / include / wx / event.h

diff --git a/include/wx/event.h b/include/wx/event.h
index bbd046aada454528d46fa5c491f43fb434e2622e..68089351630b48e44a5a9a1078f83666ffba96bd 100644 (file)
--- a/include/wx/event.h
+++ b/include/wx/event.h
@@ -2260,9 +2260,7 @@ protected:
 // ----------------------------------------------------------------------------
 
 class WXDLLIMPEXP_BASE wxEvtHandler : public wxObject
-#if wxUSE_WEAKREF
                                     , public wxTrackable
-#endif
 {
 public:
     wxEvtHandler();
@@ -2276,7 +2274,9 @@ public:
     void SetEvtHandlerEnabled(bool enabled) { m_enabled = enabled; }
     bool GetEvtHandlerEnabled() const { return m_enabled; }
 
-    // process an event right now
+    // Process an event right now: this can only be called from the main
+    // thread, use QueueEvent() for scheduling the events for
+    // processing from other threads.
     virtual bool ProcessEvent(wxEvent& event);
 
     // Process an event by calling ProcessEvent and handling any exceptions
@@ -2285,8 +2285,25 @@ public:
     // wouldn't correctly propagate to wxEventLoop.
     bool SafelyProcessEvent(wxEvent& event);
 
-    // add an event to be processed later
-    virtual void AddPendingEvent(const wxEvent& event);
+    // Schedule the given event to be processed later. It takes ownership of
+    // the event pointer, i.e. it will be deleted later. This is safe to call
+    // from multiple threads although you still need to ensure that wxString
+    // fields of the event object are deep copies and not use the same string
+    // buffer as other wxString objects in this thread.
+    virtual void QueueEvent(wxEvent *event);
+
+    // Add an event to be processed later: notice that this function is not
+    // safe to call from threads other than main, use QueueEvent()
+    virtual void AddPendingEvent(const wxEvent& event)
+    {
+        // notice that the thread-safety problem comes from the fact that
+        // Clone() doesn't make deep copies of wxString fields of wxEvent
+        // object and so the same wxString could be used from both threads when
+        // the event object is destroyed in this one -- QueueEvent() avoids
+        // this problem as the event pointer is not used any more in this
+        // thread at all after it is called.
+        QueueEvent(event.Clone());
+    }
 
     void ProcessPendingEvents();
 
@@ -2362,9 +2379,7 @@ public:
 
     // Avoid problems at exit by cleaning up static hash table gracefully
     void ClearEventHashTable() { GetEventHashTable().Clear(); }
-#if wxUSE_WEAKREF
     void OnSinkDestroyed( wxEvtHandler *sink );
-#endif
 
 private:
     static const wxEventTableEntry sm_eventTableEntries[];
@@ -2431,16 +2446,13 @@ protected:
     virtual void DoSetClientData( void *data );
     virtual void *DoGetClientData() const;
 
-#if wxUSE_WEAKREF
     // Search tracker objects for event connection with this sink
     wxEventConnectionRef *FindRefInTrackerList(wxEvtHandler *eventSink);
-#endif
 
 private:
     DECLARE_DYNAMIC_CLASS_NO_COPY(wxEvtHandler)
 };
 
-#if wxUSE_WEAKREF
 // ----------------------------------------------------------------------------
 // wxEventConnectionRef represents all connections between two event handlers
 // and enables automatic disconnect when an event handler sink goes out of
@@ -2489,17 +2501,28 @@ private:
 
     DECLARE_NO_ASSIGN_CLASS(wxEventConnectionRef)
 };
-#endif // wxUSE_WEAKREF
 
-// Post a message to the given eventhandler which will be processed during the
-// next event loop iteration
+// Post a message to the given event handler which will be processed during the
+// next event loop iteration.
+//
+// Notice that this one is not thread-safe, use wxQueueEvent()
 inline void wxPostEvent(wxEvtHandler *dest, const wxEvent& event)
 {
-    wxCHECK_RET( dest, wxT("need an object to post event to in wxPostEvent") );
+    wxCHECK_RET( dest, "need an object to post event to" );
 
     dest->AddPendingEvent(event);
 }
 
+// Wrapper around wxEvtHandler::QueueEvent(): adds an event for later
+// processing, unlike wxPostEvent it is safe to use from different thread even
+// for events with wxString members
+inline void wxQueueEvent(wxEvtHandler *dest, wxEvent *event)
+{
+    wxCHECK_RET( dest, "need an object to queue event for" );
+
+    dest->QueueEvent(event);
+}
+
 typedef void (wxEvtHandler::*wxEventFunction)(wxEvent&);
 typedef void (wxEvtHandler::*wxIdleEventFunction)(wxIdleEvent&);