-    wxTreebookEvent event(wxEVT_COMMAND_TREEBOOK_PAGE_CHANGING, m_windowId);
-    event.SetEventObject(this);
-    event.SetSelection(pagePos);
-    event.SetOldSelection(m_selection);
+    if (flags & SetSelection_SendEvent)
+    {
+        event.SetEventObject(this);
+        event.SetSelection(pagePos);
+        event.SetOldSelection(m_selection);
+
+        // don't send the event if the old and new pages are the same; do send it
+        // otherwise and be prepared for it to be vetoed
+        allowed = (int)pagePos == m_selection ||
+                  !GetEventHandler()->ProcessEvent(event) ||
+                  event.IsAllowed();
+    }