dtmdefaultbasetraversers.java

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    {
			// Compute in ID space
      int subtreeRootIdent = makeNodeIdentity(context );

      for (current = makeNodeIdentity(current) - 1; current >= 0; current--)
      {
        short type = _type(current);

        if (ATTRIBUTE_NODE == type || NAMESPACE_NODE == type)
          continue;

        return makeNodeHandle(current);  // make handle.
      }

      return NULL;
    }

    /**
     * Traverse to the next node after the current node that is matched
     * by the expanded type ID.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current, int expandedTypeID)
    {
			// Compute in ID space
      int subtreeRootIdent = makeNodeIdentity(context);

      for (current = makeNodeIdentity(current) - 1; current >= 0; current--)
      {
        int exptype = m_exptype.elementAt(current);

        if (exptype != expandedTypeID)
          continue;

        return makeNodeHandle(current);  // make handle.
      }

      return NULL;
    }
  }

  /**
   * Implements traversal of the Ancestor access, in reverse document order.
   */
  private class PrecedingSiblingTraverser extends DTMAxisTraverser
  {

    /**
     * Traverse to the next node after the current node.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current)
    {
      return getPreviousSibling(current);
    }

    /**
     * Traverse to the next node after the current node that is matched
     * by the expanded type ID.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current, int expandedTypeID)
    {

      while (DTM.NULL != (current = getPreviousSibling(current)))
      {
        if (getExpandedTypeID(current) == expandedTypeID)
          return current;
      }

      return NULL;
    }
  }

  /**
   * Implements traversal of the Self axis.
   */
  private class SelfTraverser extends DTMAxisTraverser
  {

    /**
     * By the nature of the stateless traversal, the context node can not be
     * returned or the iteration will go into an infinate loop.  To see if
     * the self node should be processed, use this function.
     *
     * @param context The context node of this traversal.
     *
     * @return the first node in the traversal.
     */
    public int first(int context)
    {
      return context;
    }

    /**
     * By the nature of the stateless traversal, the context node can not be
     * returned or the iteration will go into an infinate loop.  To see if
     * the self node should be processed, use this function.  If the context
     * node does not match the expanded type ID, this function will return
     * false.
     *
     * @param context The context node of this traversal.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the first node in the traversal.
     */
    public int first(int context, int expandedTypeID)
    {
      return (getExpandedTypeID(context) == expandedTypeID) ? context : NULL;
    }

    /**
     * Traverse to the next node after the current node.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     *
     * @return Always return NULL for this axis.
     */
    public int next(int context, int current)
    {
      return NULL;
    }

    /**
     * Traverse to the next node after the current node that is matched
     * by the expanded type ID.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current, int expandedTypeID)
    {
      return NULL;
    }
  }

  /**
   * Implements traversal of the Ancestor access, in reverse document order.
   */
  private class AllFromRootTraverser extends AllFromNodeTraverser
  {

    /**
     * Return the root.
     *
     * @param context The context node of this traversal.
     *
     * @return the first node in the traversal.
     */
    public int first(int context)
    {
      return getDocumentRoot(context);
    }

    /**
     * Return the root if it matches the expanded type ID.
     *
     * @param context The context node of this traversal.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the first node in the traversal.
     */
    public int first(int context, int expandedTypeID)
    {
      return (getExpandedTypeID(getDocumentRoot(context)) == expandedTypeID)
             ? context : next(context, context, expandedTypeID);
    }

    /**
     * Traverse to the next node after the current node.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current)
    {
			// Compute in ID space
      int subtreeRootIdent = makeNodeIdentity(context);

      for (current = makeNodeIdentity(current) + 1; ; current++)
      {
				// Kluge test: Just make sure +1 yielded a real node
        int type = _type(current);  // may call nextNode()
        if (type == NULL)
          return NULL;

        return makeNodeHandle(current);  // make handle.
      }
    }

    /**
     * Traverse to the next node after the current node that is matched
     * by the expanded type ID.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current, int expandedTypeID)
    {
			// Compute in ID space
      int subtreeRootIdent = makeNodeIdentity(context);

      for (current = makeNodeIdentity(current) + 1; ; current++)
      {
        int exptype = _exptype(current);  // may call nextNode()

        if (exptype == NULL)
          return NULL;

        if (exptype != expandedTypeID)
          continue;

        return makeNodeHandle(current);  // make handle.
      }
    }
  }

  /**
   * Implements traversal of the Self axis.
   */
  private class RootTraverser extends AllFromRootTraverser
  {
    /**
     * Return the root if it matches the expanded type ID,
     * else return null (nothing found)
     *
     * @param context The context node of this traversal.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the first node in the traversal.
     */
    public int first(int context, int expandedTypeID)
    {
      int root=getDocumentRoot(context);
      return (getExpandedTypeID(root) == expandedTypeID)
	? root : NULL;
    }

    /**
     * Traverse to the next node after the current node.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     *
     * @return Always return NULL for this axis.
     */
    public int next(int context, int current)
    {
      return NULL;
    }

    /**
     * Traverse to the next node after the current node that is matched
     * by the expanded type ID.
     *
     * @param context The context node of this iteration.
     * @param current The current node of the iteration.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the next node in the iteration, or DTM.NULL.
     */
    public int next(int context, int current, int expandedTypeID)
    {
      return NULL;
    }
  }

  /**
   * A non-xpath axis, returns all nodes that aren't namespaces or attributes,
   * from and including the root.
   */
  private class DescendantOrSelfFromRootTraverser extends DescendantTraverser
  {

    /**
     * Get the first potential identity that can be returned, which is the axis 
     * root context in this case.
     *
     * @param identity The node identity of the root context of the traversal.
     *
     * @return The identity argument.
     */
    protected int getFirstPotential(int identity)
    {
      return identity;
    }

    /**
     * Get the first potential identity that can be returned.
     * @param handle handle to the root context.
     * @return identity of the root of the subtree.
     */
    protected int getSubtreeRoot(int handle)
    {
			// %REVIEW% Shouldn't this always be 0?
      return makeNodeIdentity(getDocument());
    }

    /**
     * Return the root.
     *
     * @param context The context node of this traversal.
     *
     * @return the first node in the traversal.
     */
    public int first(int context)
    {
      return getDocumentRoot(context);
    }
    
    /**
     * By the nature of the stateless traversal, the context node can not be
     * returned or the iteration will go into an infinate loop.  So to traverse
     * an axis, the first function must be used to get the first node.
     *
     * <p>This method needs to be overloaded only by those axis that process
     * the self node. <\p>
     *
     * @param context The context node of this traversal. This is the point
     * of origin for the traversal -- its "root node" or starting point.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the first node in the traversal.
     */
    public int first(int context, int expandedTypeID)
    {
      if (isIndexed(expandedTypeID))
      {
        int identity = 0;
        int firstPotential = getFirstPotential(identity);

        return makeNodeHandle(getNextIndexed(identity, firstPotential, expandedTypeID));
      }

      int root = first(context); 
      return next(root, root, expandedTypeID);
    }
  }
  
  /**
   * A non-xpath axis, returns all nodes that aren't namespaces or attributes,
   * from but not including the root.
   */
  private class DescendantFromRootTraverser extends DescendantTraverser
  {

    /**
     * Get the first potential identity that can be returned, which is the axis 
     * root context in this case.
     *
     * @param identity The node identity of the root context of the traversal.
     *
     * @return The identity argument.
     */
    protected int getFirstPotential(int identity)
    {
      return _firstch(0);
    }

    /**
     * Get the first potential identity that can be returned.
     * @param handle handle to the root context.
     * @return identity of the root of the subtree.
     */
    protected int getSubtreeRoot(int handle)
    {
      return 0;
    }

    /**
     * Return the root.
     *
     * @param context The context node of this traversal.
     *
     * @return the first node in the traversal.
     */
    public int first(int context)
    {
      return makeNodeHandle(_firstch(0));
    }
    
    /**
     * By the nature of the stateless traversal, the context node can not be
     * returned or the iteration will go into an infinate loop.  So to traverse
     * an axis, the first function must be used to get the first node.
     *
     * <p>This method needs to be overloaded only by those axis that process
     * the self node. <\p>
     *
     * @param context The context node of this traversal. This is the point
     * of origin for the traversal -- its "root node" or starting point.
     * @param expandedTypeID The expanded type ID that must match.
     *
     * @return the first node in the traversal.
     */
    public int first(int context, int expandedTypeID)
    {
      if (isIndexed(expandedTypeID))
      {
        int identity = 0; 
        int firstPotential = getFirstPotential(identity);

        return makeNodeHandle(getNextIndexed(identity, firstPotential, expandedTypeID));
      }

      int root = getDocumentRoot(context); 
      return next(root, root, expandedTypeID);
    }
    
  }

}