org.axsl.ps

Interface PsEncoding

All Superinterfaces:

Encoding

public interface PsEncoding
extends Encoding

EncodingVector implementations represent what PostScript and PDF call an Encoding, that is a mapping from character to glyph index that is based on the character's location in an array (vector).

Encoding instances provide some standard encoding resources for PostScript. When a PostScript file is parsed, the characters in a string are really indices into an array of glyph names, which are in turn the keys to entries in a glyph dictionary. Input to a PostScript interpreter is not really characters, but rather character indexes. (The two might be the same, especially for ASCII characters).

So the PostScript interpreter uses a two-step process, as follows: 1. It conceptually maps character codes (integer values) to name objects like /A or /Uacute. This map is known as an "encoding". There are several standard encoding schemes defined in the PostScript standard that each interpreter must know how to handle. Those are provided as Encoding subclasses. 2. The name objects created in step 1 are then used as the key into a dictionary (contained in the Font dictionary) whose values contain the PostScript instructions needed to actually paint the glyph.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	PsEncoding.Predefined An enumeration of the standard encodings supported by PostScript and/or PDF.

Field Summary

Fields inherited from interface org.axsl.ps.Encoding

INVALID_UNICODE_CHAR

Method Summary

Modifier and Type	Method and Description
PsEncoding	bestBaseEncodingPdf() Method useful for determining what, if any, EncodingVector should be used as the base encoding when writing this EncodingVector in PDF.
java.lang.String[]	getGlyphNames() Returns the array of glyph names that represents this encoding.
PsEncoding.Predefined	getPredefinedType() Returns the predefined type, if any, of this encoding vector.
boolean	isSubsetOf(PsEncoding otherVector) Determines whether all items encoded in this EncodingVector are also encoded the same way in another EncodingVector.
java.lang.String	mapCodePointToGlyphName(int codePoint) Finds the glyph name that corresponds to a given Unicode code point.

Methods inherited from interface org.axsl.ps.Encoding

asPostScript, canEncode, decodeCharacter, encodeCharacter, getFirstIndex, getLastIndex, getName, isPredefinedPdf, isPredefinedPs

Method Detail

bestBaseEncodingPdf

PsEncoding bestBaseEncodingPdf()

Method useful for determining what, if any, EncodingVector should be used as the base encoding when writing this EncodingVector in PDF. In PDF, an EncodingVector can be written as a set of differences from one of the standard PDF EncodingVectors. (There does not seem to be a similar capability in PostScript).

Returns:

The best base-encoding that should be used when writing this encoding to PostScript, or null if this encoding vector should be written in its entirety.

mapCodePointToGlyphName

java.lang.String mapCodePointToGlyphName(int codePoint)

Finds the glyph name that corresponds to a given Unicode code point.

Parameters:

codePoint - The Unicode code point for which the glyph name is desired.

Returns:

The glyph name, or null if none is found in this encoding's glyph lists.

isSubsetOf

boolean isSubsetOf(PsEncoding otherVector)

Determines whether all items encoded in this EncodingVector are also encoded the same way in another EncodingVector. If so, then this instance is really superfluous.

Parameters:

otherVector - The EncodingVector instance to which this should be compared.

Returns:

True iff otherVector encodes all items that this does, and encodes them the same way.

getPredefinedType

PsEncoding.Predefined getPredefinedType()

Returns the predefined type, if any, of this encoding vector.

Returns:

The predefined type of this encoding vector, or null if this is not a predefined encoding vector.

getGlyphNames

java.lang.String[] getGlyphNames()

Returns the array of glyph names that represents this encoding. The index is the encoding index for the glyph name at that index.

Returns:

The glyph name array for this encoding.