/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 2002, International
 * Business Machines Corporation., http://www.ibm.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xpath.impl;

import org.apache.xpath.expression.ConditionalExpr;
import org.apache.xpath.expression.Expr;
import org.apache.xpath.expression.Visitor;
import org.apache.xpath.impl.parser.Node;
import org.apache.xpath.impl.parser.SimpleNode;
import org.apache.xpath.impl.parser.XPath;


/**
 * Implementation of if-then-else expression.
 */
public class ConditionalExprImpl extends ExprImpl implements ConditionalExpr
{
    /**
     * Constructor for ConditionalExprImpl.
     *
     * @param i
     */
    public ConditionalExprImpl(int i)
    {
        super(i);
        m_children = new Node[3];
    }

    /**
     * Constructor for ConditionalExprImpl.
     *
     * @param p
     * @param i
     */
    public ConditionalExprImpl(XPath p, int i)
    {
        super(p, i);
        m_children = new Node[3];
    }

    /**
     * Constructor for ConditionalExprImpl.
     *
     * @param expr DOCUMENT ME!
     */
    protected ConditionalExprImpl(ConditionalExprImpl expr)
    {
        super(expr.id);
        m_children = new Node[3];
        System.arraycopy(expr.m_children, 0, m_children, 0, 3);
    }

    /**
     * Constructor for ConditionalExprImpl.
     *
     * @param test
     * @param thenClause
     * @param elseClause DOCUMENT ME!
     */
    protected ConditionalExprImpl(Expr test, Expr thenClause, Expr elseClause)
    {
        super();
        m_children = new Node[3];
        m_children[0] = (Node) test;
        m_children[1] = (Node) thenClause;
        m_children[2] = (Node) elseClause;
    }

    /**
     * @see org.apache.xpath.expression.ConditionalExpr#getElseExpr()
     */
    public Expr getElseExpr()
    {
        return (Expr) m_children[2];
    }

    /**
     * @see org.apache.xpath.expression.ConditionalExpr#getTestExpr()
     */
    public Expr getTestExpr()
    {
        return (Expr) m_children[0];
    }

    /**
     * @see org.apache.xpath.expression.ConditionalExpr#getThenExpr()
     */
    public Expr getThenExpr()
    {
        return (Expr) m_children[1];
    }

    /* (non-Javadoc)
     * @see org.apache.xpath.expression.ConditionalExpr#setElseExpr(org.apache.xpath.expression.Expr)
     */
    public void setElseExpr(Expr expr)
    {
        m_children[2] = (Node) expr;
    }

    /* (non-Javadoc)
     * @see org.apache.xpath.expression.ConditionalExpr#setTestExpr(org.apache.xpath.expression.Expr)
     */
    public void setTestExpr(Expr expr)
    {
        m_children[0] = (Node) expr;
    }

    /* (non-Javadoc)
     * @see org.apache.xpath.expression.ConditionalExpr#setThenExpr(org.apache.xpath.expression.Expr)
     */
    public void setThenExpr(Expr expr)
    {
        m_children[1] = (Node) expr;
    }

    /**
     * @see org.apache.xpath.expression.Expr#cloneExpression()
     */
    public Expr cloneExpression()
    {
        return new ConditionalExprImpl(this);
    }

    /**
     * @see org.apache.xpath.expression.Expr#getExprType()
     */
    public short getExprType()
    {
        return CONDITIONAL_EXPR;
    }

    /**
     * @see org.apache.xpath.expression.Visitable#visit(Visitor)
     */
    public boolean visit(Visitor visitor)
    {
        if ( visitor.visitConditional(this) ) {
        	if ( getTestExpr().visit(visitor)) {
        		if ( getThenExpr().visit(visitor) ) {
        			return getElseExpr().visit(visitor);
        		}
        	}
        }
        return false;
    }

    /**
     * @see org.apache.xpath.impl.parser.Node#jjtAddChild(Node, int)
     */
    public void jjtAddChild(Node n, int i)
    {
        if (((SimpleNode) n).canBeReduced())
        {
            super.jjtAddChild(n.jjtGetChild(0), i);
        }
        else
        {
            super.jjtAddChild(n, i);
        }
    }

    /* (non-Javadoc)
     * @see org.apache.xpath.impl.parser.SimpleNode#getString(java.lang.StringBuffer, boolean)
     */
    public void getString(StringBuffer expr, boolean abbreviate)
    {
        expr.append("if (");
        ((ExprImpl) getTestExpr()).getString(expr, abbreviate);
        expr.append(") then ");
        ((ExprImpl) getThenExpr()).getString(expr, abbreviate);
        expr.append(" else ");
        ((ExprImpl) getElseExpr()).getString(expr, abbreviate);
    }
}