org.apache.fop.complexscripts.bidi

Class UnicodeBidiAlgorithm

java.lang.Object

org.apache.fop.complexscripts.bidi.UnicodeBidiAlgorithm

All Implemented Interfaces:

BidiConstants

public final class UnicodeBidiAlgorithm
extends Object
implements BidiConstants

The UnicodeBidiAlgorithm class implements functionality prescribed by the Unicode Bidirectional Algorithm, Unicode Standard Annex #9.

This work was originally authored by Glenn Adams (gadams@apache.org).

Field Summary

Fields inherited from interface org.apache.fop.complexscripts.bidi.BidiConstants

AL, AN, B, BN, CS, EN, ES, ET, FIRST, L, LAST, LRE, LRO, MAX_LEVELS, NSM, ON, OVERRIDE, PDF, R, RLE, RLO, S, SURROGATE, WS

Method Summary

Methods

Modifier and Type	Method and Description
static int[]	resolveLevels(CharSequence cs, Direction defaultLevel) Resolve the directionality levels of each character in a character seqeunce.
static int[]	resolveLevels(int[] chars, int[] classes, int defaultLevel, int[] levels, boolean useRuleL1) Resolve the directionality levels of each character in a character seqeunce.
static int[]	resolveLevels(int[] chars, int defaultLevel, int[] levels) Resolve the directionality levels of each character in a character seqeunce.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

resolveLevels

public static int[] resolveLevels(CharSequence cs,
                  Direction defaultLevel)

Resolve the directionality levels of each character in a character seqeunce. If some character is encoded in the character sequence as a Unicode Surrogate Pair, then the directionality level of each of the two members of the pair will be identical.

Parameters:

cs - input character sequence representing a UTF-16 encoded string

defaultLevel - the default paragraph level, which must be zero (LR) or one (RL)

Returns:

null if bidirectional processing is not required; otherwise, returns an array of integers, where each integer corresponds to exactly one UTF-16 encoding element present in the input character sequence, and where each integer denotes the directionality level of the corresponding encoding element

resolveLevels

public static int[] resolveLevels(int[] chars,
                  int defaultLevel,
                  int[] levels)

Resolve the directionality levels of each character in a character seqeunce.

Parameters:

chars - array of input characters represented as unicode scalar values

defaultLevel - the default paragraph level, which must be zero (LR) or one (RL)

levels - array to receive levels, one for each character in chars array

Returns:

null if bidirectional processing is not required; otherwise, returns an array of integers, where each integer corresponds to exactly one UTF-16 encoding element present in the input character sequence, and where each integer denotes the directionality level of the corresponding encoding element

resolveLevels

public static int[] resolveLevels(int[] chars,
                  int[] classes,
                  int defaultLevel,
                  int[] levels,
                  boolean useRuleL1)

Resolve the directionality levels of each character in a character seqeunce.

Parameters:

chars - array of input characters represented as unicode scalar values

classes - array containing one bidi class per character in chars array

defaultLevel - the default paragraph level, which must be zero (LR) or one (RL)

levels - array to receive levels, one for each character in chars array

useRuleL1 - true if rule L1 should be used

Returns:

null if bidirectional processing is not required; otherwise, returns an array of integers, where each integer corresponds to exactly one UTF-16 encoding element present in the input character sequence, and where each integer denotes the directionality level of the corresponding encoding element