/*
 * Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source 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, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *   Free SoftwareFoundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.relaxng.program;

import com.caucho.util.L10N;
import com.caucho.xml.QName;

import java.util.HashSet;

/**
 * Generates programs from patterns.
 */
public class TextItem extends Item {
  protected final static L10N L = new L10N(TextItem.class);

  private final static QName TEXT_NAME = new QName("#text", "");
  
  public final static TextItem TEXT = new TextItem();

  private TextItem()
  {
  }

  /**
   * Returns the first set, the set of element names possible.
   */
  public void firstSet(HashSet<QName> set)
  {
    set.add(TEXT_NAME);
  }
  
  /**
   * Text allows the empty match.
   */
  public boolean allowEmpty()
  {
    return true;
  }
  
  /**
   * Text repeats
   */
  @Override
  public Item text(CharSequence text)
  {
    return this;
  }


  /**
   * Returns the pretty printed syntax.
   */
  public String toSyntaxDescription(int depth)
  {
    return "text";
  }

  /**
   * True for simple syntax.
   */
  public boolean isSimpleSyntax()
  {
    return true;
  }

  /**
   * Returns the hash code for the empty item.
   */
  public int hashCode()
  {
    return 191;
  }

  /**
   * Returns true if the object is an empty item.
   */
  public boolean equals(Object o)
  {
    if (this == o)
      return true;
    
    if (! (o instanceof TextItem))
      return false;

    return true;
  }

  public String toString()
  {
    return "TextItem[]";
  }
}