gcc/libjava/classpath/java/text/Bidi.java

/* Bidi.java -- Bidirectional Algorithm implementation
   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.
 
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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.

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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
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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
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exception statement from your version. */


package java.text;

/**
 * Bidirectional Algorithm implementation.
 *
 * TODO/FIXME Only one method <code>requiresBidi</code> is implemented
 * for now by using <code>Character</code>. The full algorithm is <a
 * href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard
 * Annex #9: The Bidirectional Algorithm</a>. A full implementation is
 * <a href="http://fribidi.org/">GNU FriBidi</a>.
 */
public class Bidi
{
  /**
   * Returns false if all characters in the text between start and end
   * are all left-to-right text. This implementation is just calls
   * <code>Character.getDirectionality(char)</code> on all characters
   * and makes sure all characters are either explicitly left-to-right
   * or neutral in directionality (character types L, EN, ES, ET, AN,
   * CS, S and WS).
   */
  public static boolean requiresBidi(char[] text, int start, int end)
  {
    for (int i = start; i < end; i++)
      {
	byte dir = Character.getDirectionality(text[i]);
	if (dir != Character.DIRECTIONALITY_LEFT_TO_RIGHT
	    && dir != Character.DIRECTIONALITY_EUROPEAN_NUMBER
	    && dir != Character.DIRECTIONALITY_EUROPEAN_NUMBER_SEPARATOR
	    && dir != Character.DIRECTIONALITY_EUROPEAN_NUMBER_TERMINATOR
	    && dir != Character.DIRECTIONALITY_ARABIC_NUMBER
	    && dir != Character.DIRECTIONALITY_COMMON_NUMBER_SEPARATOR
	    && dir != Character.DIRECTIONALITY_SEGMENT_SEPARATOR
	    && dir != Character.DIRECTIONALITY_WHITESPACE)
	  return true;
      }

    return false;
  }
}