| // Default character BreakIterator. |
| |
| /* Copyright (C) 1999 Free Software Foundation |
| |
| This file is part of libgcj. |
| |
| This software is copyrighted work licensed under the terms of the |
| Libgcj License. Please consult the file "LIBGCJ_LICENSE" for |
| details. */ |
| |
| package gnu.gcj.text; |
| |
| import java.text.BreakIterator; |
| import java.text.CharacterIterator; |
| |
| /** |
| * @author Tom Tromey <tromey@cygnus.com> |
| * @date March 19, 1999 |
| * Written using The Unicode Standard, Version 2.0. |
| */ |
| |
| public class CharacterBreakIterator extends BaseBreakIterator |
| { |
| // Hangul Jamo constants from Unicode book. |
| private static final int LBase = 0x1100; |
| private static final int VBase = 0x1161; |
| private static final int TBase = 0x11a7; |
| private static final int LCount = 19; |
| private static final int VCount = 21; |
| private static final int TCount = 28; |
| |
| // Information about surrogates. |
| private static final int highSurrogateStart = 0xD800; |
| private static final int highSurrogateEnd = 0xDBFF; |
| private static final int lowSurrogateStart = 0xDC00; |
| private static final int lowSurrogateEnd = 0xDFFF; |
| |
| public Object clone () |
| { |
| return new CharacterBreakIterator (this); |
| } |
| |
| public CharacterBreakIterator () |
| { |
| iter = null; // FIXME? |
| } |
| |
| private CharacterBreakIterator (CharacterBreakIterator other) |
| { |
| iter = (CharacterIterator) other.iter.clone(); |
| } |
| |
| // Some methods to tell us different properties of characters. |
| private final boolean isL (char c) |
| { |
| return c >= LBase && c <= LBase + LCount; |
| } |
| private final boolean isV (char c) |
| { |
| return c >= VBase && c <= VBase + VCount; |
| } |
| private final boolean isT (char c) |
| { |
| return c >= TBase && c <= TBase + TCount; |
| } |
| private final boolean isLVT (char c) |
| { |
| return isL (c) || isV (c) || isT (c); |
| } |
| private final boolean isHighSurrogate (char c) |
| { |
| return c >= highSurrogateStart && c <= highSurrogateEnd; |
| } |
| private final boolean isLowSurrogate (char c) |
| { |
| return c >= lowSurrogateStart && c <= lowSurrogateEnd; |
| } |
| |
| public int next () |
| { |
| int end = iter.getEndIndex(); |
| if (iter.getIndex() == end) |
| return DONE; |
| |
| char c; |
| for (char prev = CharacterIterator.DONE; iter.getIndex() < end; prev = c) |
| { |
| c = iter.next(); |
| if (c == CharacterIterator.DONE) |
| break; |
| int type = Character.getType(c); |
| |
| // Break after paragraph separators. |
| if (type == Character.PARAGRAPH_SEPARATOR) |
| break; |
| |
| // Now we need some lookahead. |
| char ahead = iter.next(); |
| iter.previous(); |
| if (ahead == CharacterIterator.DONE) |
| break; |
| int aheadType = Character.getType(ahead); |
| |
| if (aheadType != Character.NON_SPACING_MARK |
| && ! isLowSurrogate (ahead) |
| && ! isLVT (ahead)) |
| break; |
| if (! isLVT (c) && isLVT (ahead)) |
| break; |
| if (isL (c) && ! isLVT (ahead) |
| && aheadType != Character.NON_SPACING_MARK) |
| break; |
| if (isV (c) && ! isV (ahead) && !isT (ahead) |
| && aheadType != Character.NON_SPACING_MARK) |
| break; |
| if (isT (c) && ! isT (ahead) |
| && aheadType != Character.NON_SPACING_MARK) |
| break; |
| |
| if (! isHighSurrogate (c) && isLowSurrogate (ahead)) |
| break; |
| if (isHighSurrogate (c) && ! isLowSurrogate (ahead)) |
| break; |
| if (! isHighSurrogate (prev) && isLowSurrogate (c)) |
| break; |
| } |
| |
| return iter.getIndex(); |
| } |
| |
| public int previous () |
| { |
| if (iter.getIndex() == iter.getBeginIndex()) |
| return DONE; |
| |
| int start = iter.getBeginIndex(); |
| while (iter.getIndex() >= iter.getBeginIndex()) |
| { |
| char c = iter.previous(); |
| if (c == CharacterIterator.DONE) |
| break; |
| int type = Character.getType(c); |
| |
| if (type != Character.NON_SPACING_MARK |
| && ! isLowSurrogate (c) |
| && ! isLVT (c)) |
| break; |
| |
| // Now we need some lookahead. |
| char ahead = iter.previous(); |
| if (ahead == CharacterIterator.DONE) |
| { |
| iter.next(); |
| break; |
| } |
| char ahead2 = iter.previous(); |
| iter.next(); |
| iter.next(); |
| if (ahead2 == CharacterIterator.DONE) |
| break; |
| int aheadType = Character.getType(ahead); |
| |
| if (aheadType == Character.PARAGRAPH_SEPARATOR) |
| break; |
| |
| if (isLVT (c) && ! isLVT (ahead)) |
| break; |
| if (! isLVT (c) && type != Character.NON_SPACING_MARK |
| && isL (ahead)) |
| break; |
| if (! isV (c) && ! isT (c) && type != Character.NON_SPACING_MARK |
| && isV (ahead)) |
| break; |
| if (! isT (c) && type != Character.NON_SPACING_MARK |
| && isT (ahead)) |
| break; |
| |
| if (isLowSurrogate (c) && ! isHighSurrogate (ahead)) |
| break; |
| if (! isLowSurrogate (c) && isHighSurrogate (ahead)) |
| break; |
| if (isLowSurrogate (ahead) && ! isHighSurrogate (ahead2)) |
| break; |
| } |
| |
| return iter.getIndex(); |
| } |
| } |