/*
 * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */


package com.sun.xml.internal.xsom.util;

import com.sun.xml.internal.xsom.XSType;

/**
 * Perform a transitive closure operation on a type to determine if it
 * belongs to this set.
 *
 * The contains method returns true iff the TypeSet contains an instance
 * of the specified XSType or any of the base types of the XSType.
 *
 * @author <a href="mailto:Ryan.Shoemaker@Sun.COM">Ryan Shoemaker</a>, Sun Microsystems, Inc.
 */
public class TypeClosure extends TypeSet {

    private final TypeSet typeSet;

    public TypeClosure(TypeSet typeSet) {
        this.typeSet = typeSet;
    }

    /* (non-Javadoc)
     * @see com.sun.xml.internal.xsom.util.TypeSet#contains(com.sun.xml.internal.xsom.XSDeclaration)
     *
     * transitive closure variation on the contains method.
     */
    public boolean contains(XSType type) {
        if( typeSet.contains(type) ) {
            return true;
        } else {
            XSType baseType = type.getBaseType();
            if( baseType == null ) {
                return false;
            } else {
                // climb the super type hierarchy
                return contains(baseType);
            }
        }
    }

}