+// ----------------------------------------------------------------------------
+// wxEventConnectionRef represents all connections between two event handlers
+// and enables automatic disconnect when an event handler sink goes out of
+// scope. Each connection/disconnect increases/decreases ref count, and
+// when it reaches zero the node goes out of scope.
+// ----------------------------------------------------------------------------
+
+class wxEventConnectionRef : public wxTrackerNode
+{
+public:
+ wxEventConnectionRef() : m_src(NULL), m_sink(NULL), m_refCount(0) { }
+ wxEventConnectionRef(wxEvtHandler *src, wxEvtHandler *sink)
+ : m_src(src), m_sink(sink), m_refCount(1)
+ {
+ m_sink->AddNode(this);
+ }
+
+ // The sink is being destroyed
+ virtual void OnObjectDestroy( )
+ {
+ if ( m_src )
+ m_src->OnSinkDestroyed( m_sink );
+ delete this;
+ }
+
+ virtual wxEventConnectionRef *ToEventConnection() { return this; }
+
+ void IncRef() { m_refCount++; }
+ void DecRef()
+ {
+ if ( !--m_refCount )
+ {
+ // The sink holds the only external pointer to this object
+ if ( m_sink )
+ m_sink->RemoveNode(this);
+ delete this;
+ }
+ }
+
+private:
+ wxEvtHandler *m_src,
+ *m_sink;
+ int m_refCount;
+
+ friend class wxEvtHandler;
+
+ DECLARE_NO_ASSIGN_CLASS(wxEventConnectionRef)
+};
+