////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2003 Oliver Burn
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.xpath;
import java.util.Iterator;
import java.util.NoSuchElementException;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
/**
* Iterator for DetailAST nodes in a syntax tree.
* @author Rick Giles
*/
public abstract class NodeIterator
implements Iterator
{
/** The DetailAST for this iterator */
private DetailAST mNode;
/**
* Constructs a <code>NodeIterator</code> for a DetailAST.
* @param aAST the DetailAST.
*/
public NodeIterator(DetailAST aAST)
{
this.mNode = getFirstNode(aAST);
}
/** @see java.util.Iterator#hasNext() */
public boolean hasNext()
{
return mNode != null;
}
/** @see java.util.Iterator#next() */
public Object next()
{
if (mNode == null) {
throw new NoSuchElementException();
}
final DetailAST ret = mNode;
mNode = getNextNode(mNode);
return ret;
}
/** @see java.util.Iterator#remove() */
public void remove()
{
throw new UnsupportedOperationException();
}
/**
* Gets the first node of an iterator over a DetailAST.
* @param aAST the DetailAST.
* @return the first node of an iterator over aAST.
*/
protected abstract DetailAST getFirstNode(DetailAST aAST);
/**
* Gets the next node for an iterator over a DetailAST.
* @param aAST the DetailAST.
* @return the next node of aAST.
*/
protected abstract DetailAST getNextNode(DetailAST aAST);
/**
* Gets the previous sibling of a DetailAST.
* @param aAST the DetailAST.
* @return the previous sibling of aAST.
*/
protected DetailAST getPreviousSibling(DetailAST aAST)
{
return aAST.getPreviousSibling();
}
/**
* Get the next sibling of a DetailAST.
* @param aAST the DetailAST.
* @return the next sibling of aAST.
*/
protected DetailAST getNextSibling(DetailAST aAST)
{
return (DetailAST) aAST.getNextSibling();
}
/**
* Get the first child of a DetailAST.
* @param aAST the DetailAST.
* @return the first child of aAST.
*/
protected DetailAST getFirstChild(DetailAST aAST)
{
return (DetailAST) aAST.getFirstChild();
}
/**
* Get the last child of a DetailAST.
* @param aAST the DetailAST.
* @return the last child of aAST.
*/
protected DetailAST getLastChild(DetailAST aAST)
{
return aAST.getLastChild();
}
}