org.apache.batik.gvt.text
Class ArabicTextHandler

java.lang.Object
  |
  +--org.apache.batik.gvt.text.ArabicTextHandler

public class ArabicTextHandler

extends java.lang.Object

Handles the processing of arabic text. In particular it determines the form each arabic char should take. It also contains methods for substituting plain arabic glyphs with their shaped forms. This is needed when the arabic text is rendered using an AWT font.

Constructor Summary

ArabicTextHandler()

Method Summary

static boolean	arabicChar(char c) Returns true if the char is a standard arabic char.
static boolean	arabicCharTransparent(char c) Returns true if the char is transparent.
static java.text.AttributedString	assignArabicForms(java.text.AttributedString as) If the AttributedString contains any arabic chars, assigns an arabic form attribute, ie.
static boolean	charStartsLigature(char c) Returns true if a ligature exists that starts with the specified character.
static boolean	containsArabic(java.text.AttributedCharacterIterator aci) Returns true if the ACI contains any arabic characters.
static boolean	containsArabic(java.text.AttributedString as) Returns true if the string contains any arabic characters.
static java.lang.String	createSubstituteString(java.text.AttributedCharacterIterator aci) Where possible substitues plain arabic glyphs with their shaped forms.
static int	getNumChars(char c) Returns the number of characters the glyph for the specified character represents.
static int	getSubstituteChar(java.lang.String unicode, int form) Will try and find a substitute character of the specified form.
static boolean	isLigature(char c) Returns true if the glyph for the specified character respresents a ligature.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArabicTextHandler

public ArabicTextHandler()

Method Detail

assignArabicForms

public static java.text.AttributedString assignArabicForms(java.text.AttributedString as)

If the AttributedString contains any arabic chars, assigns an arabic form attribute, ie. initial|medial|terminal|isolated, to each arabic char.

Parameters:

as - The string to attach the arabic form attributes to.

Returns:

An attributed string with arabic form attributes.

arabicChar

public static boolean arabicChar(char c)

Returns true if the char is a standard arabic char. (ie. within the range U+0600 - U+6FF)

Parameters:

c - The character to test.

Returns:

True if the char is arabic, false otherwise.

containsArabic

public static boolean containsArabic(java.text.AttributedString as)

Returns true if the string contains any arabic characters.

Parameters:

as - The string to test.

Returns:

True if at least one char is arabic, false otherwise.

containsArabic

public static boolean containsArabic(java.text.AttributedCharacterIterator aci)

Returns true if the ACI contains any arabic characters.

Parameters:

aci - The AttributedCharacterIterator to test.

Returns:

True if at least one char is arabic, false otherwise.

arabicCharTransparent

public static boolean arabicCharTransparent(char c)

Returns true if the char is transparent.

Parameters:

c - The character to test.

Returns:

True if the character is transparent, false otherwise.

getSubstituteChar

public static int getSubstituteChar(java.lang.String unicode,
                                    int form)

Will try and find a substitute character of the specified form.

Parameters:

unicode - The unicode value of the glyph to try and replace. It may be ligature and so may contain more than one character.

form - Indicates the required arabic form. (isolated = 1, final = 2, initial = 3, medial = 4)

Returns:

The unicode value of the substutute char, or -1 if no susbtitue exists.

createSubstituteString

public static java.lang.String createSubstituteString(java.text.AttributedCharacterIterator aci)

Where possible substitues plain arabic glyphs with their shaped forms. This is needed when the arabic text is rendered using an AWT font. Simple arabic ligatures will also be recognised and replaced by a single character so the length of the resulting string may be shorter than the number of characters in the aci.

Parameters:

aci - Contains the text to process. Arabic form attributes should already be assigned to each arabic character.

Returns:

A String containing the shaped versions of the arabic characters.

charStartsLigature

public static boolean charStartsLigature(char c)

Returns true if a ligature exists that starts with the specified character.

Parameters:

c - The character to test.

Returns:

True if there is a ligature that starts with c, false otherwise.

getNumChars

public static int getNumChars(char c)

Returns the number of characters the glyph for the specified character represents. If the glyph represents a ligature this will be 2, otherwise 1.

Parameters:

c - The character to test.

Returns:

The number of characters the glyph for c represents.

isLigature

public static boolean isLigature(char c)

Returns true if the glyph for the specified character respresents a ligature.

Parameters:

c - The character to test.

Returns:

True if c is a ligature, false otherwise.