content: /*
   *  This file is part of AndroidIDE.
   *
   *  AndroidIDE 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 3 of the License, or
   *  (at your option) any later version.
   *
   *  AndroidIDE 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 for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * reserved comment block
   * DO NOT REMOVE OR ALTER!
   */
  /*
   * Copyright 1999-2004 The Apache Software Foundation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package jaxp.sun.org.apache.regexp.internal;
  
  import java.io.InputStream;
  import java.io.IOException;
  
  /**
   * Encapsulates java.io.InputStream as CharacterIterator.
   *
   * @author <a href="mailto:ales.novak@netbeans.com">Ales Novak</a>
   */
  public final class StreamCharacterIterator implements CharacterIterator
  {
      /** Underlying is */
      private final InputStream is;
  
      /** Buffer of read chars */
      private final StringBuffer buff;
  
      /** read end? */
      private boolean closed;
  
      /** @param is an InputStream, which is parsed */
      public StreamCharacterIterator(InputStream is)
      {
          this.is = is;
          this.buff = new StringBuffer(512);
          this.closed = false;
      }
  
      /** @return a substring */
      public String substring(int beginIndex, int endIndex)
      {
          try
          {
              ensure(endIndex);
              return buff.toString().substring(beginIndex, endIndex);
          }
          catch (IOException e)
          {
              throw new StringIndexOutOfBoundsException(e.getMessage());
          }
      }
  
      /** @return a substring */
      public String substring(int beginIndex)
      {
          try
          {
              readAll();
              return buff.toString().substring(beginIndex);
          }
          catch (IOException e)
          {
              throw new StringIndexOutOfBoundsException(e.getMessage());
          }
      }
  
  
      /** @return a character at the specified position. */
      public char charAt(int pos)
      {
          try
          {
              ensure(pos);
              return buff.charAt(pos);
          }
          catch (IOException e)
          {
              throw new StringIndexOutOfBoundsException(e.getMessage());
          }
      }
  
      /** @return <tt>true</tt> iff if the specified index is after the end of the character stream */
      public boolean isEnd(int pos)
      {
          if (buff.length() > pos)
          {
              return false;
          }
          else
          {
              try
              {
                  ensure(pos);
                  return (buff.length() <= pos);
              }
              catch (IOException e)
              {
                  throw new StringIndexOutOfBoundsException(e.getMessage());
              }
          }
      }
  
      /** Reads n characters from the stream and appends them to the buffer */
      private int read(int n) throws IOException
      {
          if (closed)
          {
              return 0;
          }
  
          int c;
          int i = n;
          while (--i >= 0)
          {
              c = is.read();
              if (c < 0) // EOF
              {
                  closed = true;
                  break;
              }
              buff.append((char) c);
          }
          return n - i;
      }
  
      /** Reads rest of the stream. */
      private void readAll() throws IOException
      {
          while(! closed)
          {
              read(1000);
          }
      }
  
      /** Reads chars up to the idx */
      private void ensure(int idx) throws IOException
      {
          if (closed)
          {
              return;
          }
  
          if (idx < buff.length())
          {
              return;
          }
  
          read(idx + 1 - buff.length());
      }
  }
  