khtml/dom/dom_misc.h

   1 /*
   2  * This file is part of the DOM implementation for KDE.
   3  *
   4  * Copyright 1999 Lars Knoll (knoll@kde.org)
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public License
  17  * along with this library; see the file COPYING.LIB.  If not, write to
  18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  *
  21  */
  22 #ifndef _DOM_RefCountImpl_h_
  23 #define _DOM_RefCountImpl_h_
  24
  25 #include <khtml_export.h>
  26
  27 namespace DOM {
  28
  29 /*
  30  * This implements the reference counting scheme used for all internal
  31  * DOM objects.
  32  *
  33  * Other objects should overload deleteMe() to fit their needs. The default
  34  * implementation deletes the object if the ref count drops to 0.
  35  */
  36 class KHTML_EXPORT DomShared
  37 {
  38 public:
  39   DomShared() : _ref( 0 ) {}
  40   virtual ~DomShared();
  41
  42   /* Overload this function if you want a different deletion behavior
  43    */
  44   virtual bool deleteMe();
  45
  46   void ref() { _ref++; }
  47   void deref() { if(_ref) _ref--; if(!_ref && deleteMe()) delete this; }
  48   bool hasOneRef() const { return _ref == 1; }
  49   unsigned int refCount() const { return _ref; }
  50
  51 protected:
  52     // the number of DOMObjects referencing this Node
  53     // An implementation object will delete itself, if it has
  54     // no DOMObject referencing it, and deleteMe() returns true.
  55     unsigned int _ref;
  56 };
  57
  58 } // namespace
  59
  60 #endif