svx/source/inc/treevisitor.hxx

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   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #ifndef INCLUDED_SVX_SOURCE_INC_TREEVISITOR_HXX
  21 #define INCLUDED_SVX_SOURCE_INC_TREEVISITOR_HXX
  22
  23 #include <stack>
  24
  25 template< class ELEMENT, class NODEINFO, class PROCESSOR >
  26 class TreeVisitor
  27 {
  28 public:
  29     TreeVisitor( NODEINFO _nodeInfo )
  30         :m_visitedRoot( false )
  31         ,m_root()
  32         ,m_current()
  33         ,m_nodeInfo( _nodeInfo )
  34     {
  35     }
  36
  37     void    process( const ELEMENT& _root, PROCESSOR& _processor )
  38     {
  39         m_root = _root;
  40         m_visitedRoot = false;
  41
  42         while ( do_step() )
  43             _processor.process( m_current );
  44     }
  45
  46 private:
  47     bool    do_step();
  48
  49 private:
  50     bool            m_visitedRoot;
  51     ELEMENT         m_root;
  52     ELEMENT         m_current;
  53     const NODEINFO  m_nodeInfo;
  54
  55     ::std::stack< size_t >  m_pathToCurrent;
  56     ::std::stack< ELEMENT > m_currentAncestors;
  57 };
  58
  59 template< class ELEMENT, class NODEINFO, class PROCESSOR >
  60 bool TreeVisitor< ELEMENT, NODEINFO, PROCESSOR >::do_step()
  61 {
  62     if ( !m_visitedRoot )
  63     {
  64         m_current = m_root;
  65         m_visitedRoot = true;
  66         return true;
  67     }
  68
  69     // can we step down from the current node?
  70     size_t childCount = m_nodeInfo.childCount( m_current );
  71     if ( childCount )
  72     {
  73         m_currentAncestors.push( m_current );
  74         m_current = m_nodeInfo.getChild( m_current, 0 );
  75         m_pathToCurrent.push( 0 );
  76         return true;
  77     }
  78
  79     // is there a right sibling of the current node?
  80     while ( !m_pathToCurrent.empty() )
  81     {
  82         const ELEMENT& currentParent = m_currentAncestors.top();
  83         childCount = m_nodeInfo.childCount( currentParent );
  84
  85         size_t currentChildPos = m_pathToCurrent.top();
  86         if ( ++currentChildPos < childCount )
  87         {
  88             // yes there is
  89             m_pathToCurrent.top() = currentChildPos;
  90             m_current = m_nodeInfo.getChild( currentParent, currentChildPos );
  91             return true;
  92         }
  93
  94         // no there isn't => step up
  95         m_currentAncestors.pop();
  96         m_pathToCurrent.pop();
  97     }
  98
  99     return false;
 100 }
 101
 102 #endif // INCLUDED_SVX_SOURCE_INC_TREEVISITOR_HXX
 103
 104 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */