/*
 * $Header: /l/extreme/cvs/codes/XPP3/java/src/java/xpath/org/xmlpull/v1/builder/xpath/jaxen/ContextSupport.java,v 1.1 2004/06/16 15:55:34 aslom Exp $
 * $Revision: 1.1 $
 * $Date: 2004/06/16 15:55:34 $
 *
 * ====================================================================
 *
 * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
 * 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 disclaimer that follows 
 *    these conditions in the documentation and/or other materials 
 *    provided with the distribution.
 *
 * 3. The name "Jaxen" must not be used to endorse or promote products
 *    derived from this software without prior written permission.  For
 *    written permission, please contact license@jaxen.org.
 * 
 * 4. Products derived from this software may not be called "Jaxen", nor
 *    may "Jaxen" appear in their name, without prior written permission
 *    from the Jaxen Project Management (pm@jaxen.org).
 * 
 * In addition, we request (but do not require) that you include in the 
 * end-user documentation provided with the redistribution and/or in the 
 * software itself an acknowledgement equivalent to the following:
 *     "This product includes software developed by the
 *      Jaxen Project (http://www.jaxen.org/)."
 * Alternatively, the acknowledgment may be graphical using the logos 
 * available at http://www.jaxen.org/
 *
 * 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 Jaxen AUTHORS OR THE PROJECT
 * 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
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * 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 Jaxen Project and was originally 
 * created by bob mcwhirter <bob@werken.com> and 
 * James Strachan <jstrachan@apache.org>.  For more information on the 
 * Jaxen Project, please see <http://www.jaxen.org/>.
 * 
 * $Id: ContextSupport.java,v 1.1 2004/06/16 15:55:34 aslom Exp $
 */


package org.xmlpull.v1.builder.xpath.jaxen;

import java.io.Serializable;

/** Supporting context information for resolving
 *  namespace prefixess, functions, and variables.
 * 
 *  <p>
 *  <b>NOTE:</b> This class is not typically used directly,
 *  but is exposed for writers of implementation-specific
 *  XPath packages.
 *  </p>
 *
 *  @see org.jaxen.dom4j.Dom4jXPath XPath for dom4j
 *  @see org.jaxen.jdom.JDOMXPath  XPath for JDOM
 *  @see org.jaxen.dom.DOMXPath   XPath for W3C DOM
 *  @see org.jaxen.exml.ElectricXPath  XPath for Electric XML
 *
 *  @author bob mcwhirter (bob@werken.com)
 */
public class ContextSupport implements Serializable
{
    private transient FunctionContext  functionContext;
    
    private NamespaceContext namespaceContext;
    private VariableContext  variableContext;
    
    private Navigator        navigator;
    
    /** Construct an empty <code>ContextSupport</code>.
     */
    public ContextSupport()
    {
        // intentionally left blank
    }

    /** Construct.
     *
     *  @param namespaceContext The NamespaceContext.
     *  @param functionContext The FunctionContext.
     *  @param variableContext The VariableContext.
     */
    public ContextSupport(NamespaceContext namespaceContext,
                          FunctionContext  functionContext,
                          VariableContext  variableContext,
                          Navigator        navigator)
    {
        setNamespaceContext( namespaceContext );
        setFunctionContext( functionContext );
        setVariableContext( variableContext );
        this.navigator = navigator;
    }

    public void setNamespaceContext(NamespaceContext namespaceContext)
    {
        this.namespaceContext = namespaceContext;
    }

    public void setFunctionContext(FunctionContext functionContext)
    {
        this.functionContext  = functionContext;
    }

    public void setVariableContext(VariableContext variableContext)
    {
        this.variableContext  = variableContext;
    }

    public NamespaceContext getNamespaceContext()
    {
        return this.namespaceContext;
    }

    public FunctionContext getFunctionContext()
    {
        return this.functionContext;
    }

    public VariableContext getVariableContext()
    {
        return this.variableContext;
    }

    public Navigator getNavigator()
    {
        return this.navigator;
    }

    public String translateNamespacePrefixToUri(String prefix)
    {
        NamespaceContext context = getNamespaceContext();

        if ( context != null )
        {
            return context.translateNamespacePrefixToUri( prefix );
        }

        return null;
    }

    public Object getVariableValue( String namespaceURI,
                                    String prefix,
                                    String localName )
        throws UnresolvableException
    {
        VariableContext context = getVariableContext();

        if ( context != null )
        {
            return context.getVariableValue( namespaceURI, prefix, localName );
        }
        else
        {
            throw new UnresolvableException( "No variable context installed" );
        }
    }

    public Function getFunction( String namespaceURI,
                                 String prefix,
                                 String localName )
        throws UnresolvableException
    {
        FunctionContext context = getFunctionContext();

        if ( context != null )
        {
            return context.getFunction( namespaceURI, prefix, localName );
        }
        else
        {
            throw new UnresolvableException( "No function context installed" );
        }
    }
}
