Class Bidi

public static final int DIRECTION_DEFAULT_LEFT_TO_RIGHT

This indicates that a strongly directional character in the text should set the initial direction, but if no such character is found, then the initial direction will be left-to-right.

Field Value:

-2

public static final int DIRECTION_DEFAULT_RIGHT_TO_LEFT

This indicates that a strongly directional character in the text should set the initial direction, but if no such character is found, then the initial direction will be right-to-left.

Field Value:

-1

public static final int DIRECTION_LEFT_TO_RIGHT

This indicates that the initial direction should be left-to-right.

Field Value:

0

public static final int DIRECTION_RIGHT_TO_LEFT

This indicates that the initial direction should be right-to-left.

Field Value:

1

public Bidi(char[] text,
            int offset,
            byte[] embeddings,
            int embedOffset,
            int length,
            int flags)

Create a new Bidi object with the indicated text and, possibly, explicit embedding settings. If the embeddings array is null, it is ignored. Otherwise it is taken to be explicit embedding settings corresponding to the text. Positive values from 1 to 61 are embedding levels, and negative values from -1 to -61 are embedding overrides. (FIXME: not at all clear what this really means.)

Parameters:

text - the text to use

offset - the offset of the first character of the text

embeddings - the explicit embeddings, or null if there are none

embedOffset - the offset of the first embedding value to use

length - the length of both the text and the embeddings

flags - a flag indicating the base embedding direction

public Bidi(String text,
            int flags)

Create a new Bidi object using the contents of the given String as the text.

Parameters:

text - the text to use

flags - a flag indicating the base embedding direction

public Bidi(AttributedCharacterIterator iter)

Create a new Bidi object given an attributed character iterator. This constructor will examine various attributes of the text:

• TextAttribute.RUN_DIRECTION is used to determine the paragraph's base embedding level. This constructor will recognize either TextAttribute.RUN_DIRECTION_LTR or TextAttribute.RUN_DIRECTION_RTL. If neither is given, DIRECTION_DEFAULT_LEFT_TO_RIGHT is assumed.
• If TextAttribute.NUMERIC_SHAPING is seen, then numeric shaping will be done before the Bidi algorithm is run.
• If TextAttribute.BIDI_EMBEDDING is seen on a given character, then the value of this attribute will be used as an embedding level override.

Parameters:

iter - the attributed character iterator to use

public boolean baseIsLeftToRight()

Return true if the paragraph base embedding is left-to-right, false otherwise.

public Bidi createLineBidi(int start,
                           int end)

Create a new Bidi object for a single line of text, taken from the text used when creating the current Bidi object.

Parameters:

start - the index of the first character of the line

end - the index of the final character of the line

Returns:

a new Bidi object for the indicated line of text

public int getBaseLevel()

Return the base embedding level of the paragraph.

public int getLength()

Return the length of the paragraph, in characters.

public int getLevelAt(int offset)

Return the level at the indicated character. If the supplied index is less than zero or greater than the length of the text, then the paragraph's base embedding level will be returned.

Parameters:

offset - the character to examine

Returns:

the level of that character

public int getRunCount()

Return the number of runs in the result. A run is a sequence of characters at the same embedding level.

public int getRunLevel(int which)

Return the level of the indicated run.

Parameters:

which - the run to examine

Returns:

the level of that run

public int getRunLimit(int which)

Return the index of the character just following the end of the indicated run.

Parameters:

which - the run to examine

Returns:

the index of the character after the final character of the run

public int getRunStart(int which)

Return the index of the first character in the indicated run.

Parameters:

which - the run to examine

Returns:

the index of the first character of the run

public boolean isLeftToRight()

Return true if the text is entirely left-to-right, and the base embedding is also left-to-right.

public boolean isMixed()

Return true if the text consists of mixed left-to-right and right-to-left runs, or if the text consists of one kind of run which differs from the base embedding direction.

public boolean isRightToLeft()

Return true if the text is entirely right-to-left, and the base embedding is also right-to-left.

public static void reorderVisually(byte[] levels,
                                   int levelOffset,
                                   Object[] objs,
                                   int objOffset,
                                   int count)

Reorder objects according to the levels passed in. This implements reordering as defined by the Unicode bidirectional layout specification. The levels are integers from 0 to 62; even numbers represent left-to-right runs, and odd numbers represent right-to-left runs.

Parameters:

levels - the levels associated with each object

levelOffset - the index of the first level to use

objs - the objects to reorder according to the levels

objOffset - the index of the first object to use

count - the number of objects (and levels) to manipulate

public static boolean requiresBidi(char[] text,
                                   int start,
                                   int end)

Returns false if all characters in the text between start and end are all left-to-right text. This implementation is just calls Character.getDirectionality(char) 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 String toString()

Return a String describing the internal state of this object. This is only useful for debugging.

Overrides:

toString in interface Object