Class NumericShaper

public final class NumericShaper extends Object implements Serializable

The NumericShaper class is used to convert Latin-1 (European) digits to other Unicode decimal digits. Users of this class will primarily be people who wish to present data using national digit shapes, but find it more convenient to represent the data internally using Latin-1 (European) digits. This does not interpret the deprecated numeric shape selector character (U+206E).

Instances of NumericShaper are typically applied as attributes to text with the NUMERIC_SHAPING attribute of the TextAttribute class. For example, this code snippet causes a TextLayout to shape European digits to Arabic in an Arabic context:

 Map map = new HashMap();
 map.put(TextAttribute.NUMERIC_SHAPING,
     NumericShaper.getContextualShaper(NumericShaper.ARABIC));
 FontRenderContext frc = ...;
 TextLayout layout = new TextLayout(text, map, frc);
 layout.draw(g2d, x, y);
 

It is also possible to perform numeric shaping explicitly using instances of NumericShaper, as this code snippet demonstrates:

 char[] text = ...;
 // shape all EUROPEAN digits (except zero) to ARABIC digits
 NumericShaper shaper = NumericShaper.getShaper(NumericShaper.ARABIC);
 shaper.shape(text, start, count);

 // shape European digits to ARABIC digits if preceding text is Arabic, or
 // shape European digits to TAMIL digits if preceding text is Tamil, or
 // leave European digits alone if there is no preceding text, or
 // preceding text is neither Arabic nor Tamil
 NumericShaper shaper =
     NumericShaper.getContextualShaper(NumericShaper.ARABIC |
                                         NumericShaper.TAMIL,
                                       NumericShaper.EUROPEAN);
 shaper.shape(text, start, count);
 

Bit mask- and enum-based Unicode ranges

This class supports two different programming interfaces to represent Unicode ranges for script-specific digits: bit mask-based ones, such as NumericShaper.ARABIC, and enum-based ones, such as NumericShaper.Range.ARABIC. Multiple ranges can be specified by ORing bit mask-based constants, such as:

 NumericShaper.ARABIC | NumericShaper.TAMIL
 

or creating a Set with the NumericShaper.Range constants, such as:

 EnumSet.of(NumericShaper.Range.ARABIC, NumericShaper.Range.TAMIL)
 

The enum-based ranges are a super set of the bit mask-based ones.

If the two interfaces are mixed (including serialization), Unicode range values are mapped to their counterparts where such mapping is possible, such as NumericShaper.Range.ARABIC from/to NumericShaper.ARABIC. If any unmappable range values are specified, such as NumericShaper.Range.BALINESE, those ranges are ignored.

Decimal Digits Precedence

A Unicode range may have more than one set of decimal digits. If multiple decimal digits sets are specified for the same Unicode range, one of the sets will take precedence as follows.

NumericShaper constants precedence

Unicode Range	NumericShaper Constants	Precedence
Arabic	NumericShaper.ARABIC NumericShaper.EASTERN_ARABIC	NumericShaper.EASTERN_ARABIC
	NumericShaper.Range.ARABIC NumericShaper.Range.EASTERN_ARABIC	NumericShaper.Range.EASTERN_ARABIC
Tai Tham	NumericShaper.Range.TAI_THAM_HORA NumericShaper.Range.TAI_THAM_THAM	NumericShaper.Range.TAI_THAM_THAM