class implements the
Unicode Version 3.0 Bidirectional
Algorithm” for working with Arabic and Hebrew text
in which letters run right-to-left and numbers run left-to-right. It
is named after the first four letters of
“bidirectional.” A full description
of the bidirectional text handling and the bidirectional algorithim
is beyond the scope of this book, but the simplest use case for this
class is outlined here. Create a
Bidi object by
AttributedCharacterIterator or a
String and one of the
constants (to indicate the base direction of the text) to the
Bidi( ) constructor. Or use
createLineBidi( ) to return a substring of an
Bidi object (this is usually done when
formatting a paragraph of text to fit on individual lines).
Once you have a
Bidi object, use
isLeftToRight( ) and
) to determine whether all the text has the same direction.
If both of these methods return
false (which is
the same as
isMixed( ) returning
true) then you cannot treat the text as a single
run of uni-directional text. In this case, you must break it into two
or more runs of unidirectional text.
) returns the number of distinct runs of text. For each
such numbered run,
getRunStart( ) returns the
index of the first character of the run, and
) returns the index of the first character past the end of
getRunLevel( ) returns the
level of the text, which is an integer that represents the direction and nesting level ...
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