Subversion Repositories scarts

/* textPreProcessor.java --

   Copyright (C) 2005 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath 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, or (at your option)

any later version.

GNU Classpath 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 GNU Classpath; see the file COPYING.  If not, write to the

Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301 USA.

Linking this library statically or dynamically with other modules is

making a combined work based on this library.  Thus, the terms and

conditions of the GNU General Public License cover the whole

combination.

As a special exception, the copyright holders of this library give you

permission to link this library with independent modules to produce an

executable, regardless of the license terms of these independent

modules, and to copy and distribute the resulting executable under

terms of your choice, provided that you also meet, for each linked

independent module, the terms and conditions of the license of that

module.  An independent module is a module which is not derived from

or based on this library.  If you modify this library, you may extend

this exception to your version of the library, but you are not

obligated to do so.  If you do not wish to do so, delete this

exception statement from your version. */

package gnu.javax.swing.text.html.parser.support;

import gnu.javax.swing.text.html.parser.support.low.Constants;

/**

 * Pre - processes text in text parts of the html document.

 * Not thread - safe.

 * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)

 */

public class textPreProcessor

{

  /**

   * Pre - process non-preformatted text.

   * \t, \r and \n mutate into spaces, then multiple spaces mutate

   * into single one, all whitespace around tags is consumed.

   * The content of the passed buffer is destroyed.

   * @param text A text to pre-process.

   */

  public char[] preprocess(StringBuffer a_text)

  {

    if (a_text.length() == 0)

      return null;

    char[] text = toCharArray(a_text);

    int a = 0;

    int b = text.length - 1;

    try

      {

        while (Constants.bWHITESPACE.get(text [ a ]))

          a++;

        while (Constants.bWHITESPACE.get(text [ b ]))

          b--;

      }

    catch (ArrayIndexOutOfBoundsException sx)

      {

        // A text fragment, consisting from line breaks only.

        return null;

      }

    a_text.setLength(0);

    boolean spacesWere = false;

    boolean spaceNow;

    char c;

    chars:

    for (int i = a; i <= b; i++)

      {

        c = text [ i ];

        spaceNow = Constants.bWHITESPACE.get(c);

        if (spacesWere && spaceNow)

          continue chars;

        if (spaceNow)

          a_text.append(' ');

        else

          a_text.append(c);

        spacesWere = spaceNow;

      }

    if (a_text.length() == text.length)

      {

        a_text.getChars(0, a_text.length(), text, 0);

        return text;

      }

    else

      return toCharArray(a_text);

  }

  /**

   * Pre - process pre-formatted text.

   * Heading/closing spaces and tabs preserved.

   * ONE  bounding \r, \n or \r\n is removed.

   * \r or \r\n mutate into \n. Tabs are

   * preserved.

   * The content of the passed buffer is destroyed.

   * @param text

   * @return

   */

  public char[] preprocessPreformatted(StringBuffer a_text)

  {

    if (a_text.length() == 0)

      return null;

    char[] text = toCharArray(a_text);

    int a = 0;

    int n = text.length - 1;

    int b = n;

    if (text [ 0 ] == '\n')

      a++;

    else

      {

        if (text [ 0 ] == '\r')

          {

            a++;

            if (text.length > 1 && text [ 1 ] == '\n')

              a++;

          }

      }

    if (text [ n ] == '\r')

      b--;

    else

      {

        if (text [ n ] == '\n')

          {

            b--;

            if (n > 0 && text [ n - 1 ] == '\r')

              b--;

          }

      }

    a_text.setLength(0);

    if (a > b)

      return null;

    char c;

    for (int i = a; i <= b; i++)

      {

        c = text [ i ];

        if (c == '\r')

          {

            if (i == b || text [ i + 1 ] != '\n')

              a_text.append('\n');

          }

        else

          a_text.append(c);

      }

    if (a_text.length() == text.length)

      {

        a_text.getChars(0, a_text.length(), text, 0);

        return text;

      }

    else

      return toCharArray(a_text);

  }

  /**

   * Return array of chars, present in the given buffer.

   * @param a_text The buffer

   * @return

   */

  private static char[] toCharArray(StringBuffer a_text)

  {

    char[] text = new char[ a_text.length() ];

    a_text.getChars(0, text.length, text, 0);

    return text;

  }

}