Add wx headers and ext

wxheaders/wx/tracker.h

@@ -0,0 +1,91 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/tracker.h
+// Purpose:     Support class for object lifetime tracking (wxWeakRef<T>)
+// Author:      Arne Steinarson
+// Created:     28 Dec 07
+// Copyright:   (c) 2007 Arne Steinarson
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_TRACKER_H_
+#define _WX_TRACKER_H_
+
+#include "wx/defs.h"
+
+class wxEventConnectionRef;
+
+// This class represents an object tracker and is stored in a linked list
+// in the tracked object. It is only used in one of its derived forms.
+class WXDLLIMPEXP_BASE wxTrackerNode
+{
+public:
+    wxTrackerNode() : m_nxt(NULL) { }
+    virtual ~wxTrackerNode() { }
+
+    virtual void OnObjectDestroy() = 0;
+
+    virtual wxEventConnectionRef *ToEventConnection() { return NULL; }
+
+private:
+    wxTrackerNode *m_nxt;
+
+    friend class wxTrackable;        // For list access
+    friend class wxEvtHandler;       // For list access
+};
+
+// Add-on base class for a trackable object.
+class WXDLLIMPEXP_BASE wxTrackable
+{
+public:
+    void AddNode(wxTrackerNode *prn)
+    {
+        prn->m_nxt = m_first;
+        m_first = prn;
+    }
+
+    void RemoveNode(wxTrackerNode *prn)
+    {
+        for ( wxTrackerNode **pprn = &m_first; *pprn; pprn = &(*pprn)->m_nxt )
+        {
+            if ( *pprn == prn )
+            {
+                *pprn = prn->m_nxt;
+                return;
+            }
+        }
+
+        wxFAIL_MSG( "removing invalid tracker node" );
+    }
+
+    wxTrackerNode *GetFirst() const { return m_first; }
+
+protected:
+    // this class is only supposed to be used as a base class but never be
+    // created nor destroyed directly so all ctors and dtor are protected
+
+    wxTrackable() : m_first(NULL) { }
+
+    // copy ctor and assignment operator intentionally do not copy m_first: the
+    // objects which track the original trackable shouldn't track the new copy
+    wxTrackable(const wxTrackable& WXUNUSED(other)) : m_first(NULL) { }
+    wxTrackable& operator=(const wxTrackable& WXUNUSED(other)) { return *this; }
+
+    // dtor is not virtual: this class is not supposed to be used
+    // polymorphically and adding a virtual table to it would add unwanted
+    // overhead
+    ~wxTrackable()
+    {
+        // Notify all registered refs
+        while ( m_first )
+        {
+            wxTrackerNode * const first = m_first;
+            m_first = first->m_nxt;
+            first->OnObjectDestroy();
+        }
+    }
+
+    wxTrackerNode *m_first;
+};
+
+#endif // _WX_TRACKER_H_
+