org.apache.batik.gvt.text
Class ArabicTextHandler

java.lang.Object
  extended by org.apache.batik.gvt.text.ArabicTextHandler

public class ArabicTextHandler
extends 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.


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 AttributedString assignArabicForms(AttributedString as)
          If the AttributedString contains any arabic chars, assigns an arabic form attribute, i.e. initial|medial|terminal|isolated, to each arabic char.
static boolean charStartsLigature(char c)
          Returns true if a ligature exists that starts with the specified character.
static boolean containsArabic(AttributedCharacterIterator aci)
          Returns true if the ACI contains any arabic characters.
static boolean containsArabic(AttributedString as)
          Returns true if the string contains any arabic characters.
static String createSubstituteString(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(char ch1, char ch2, int form)
          Will try and find a substitute character of the specified form.
static int getSubstituteChar(char ch, int form)
           
static boolean hasSubstitute(char ch1, char ch2)
           
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
 

Method Detail

assignArabicForms

public static AttributedString assignArabicForms(AttributedString as)
If the AttributedString contains any arabic chars, assigns an arabic form attribute, i.e. 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(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(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.

hasSubstitute

public static boolean hasSubstitute(char ch1,
                                    char ch2)

getSubstituteChar

public static int getSubstituteChar(char ch1,
                                    char ch2,
                                    int form)
Will try and find a substitute character of the specified form.

Parameters:
ch1 - The first character of two to replace.
ch2 - The second character of two to replace.
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 substitute exists.

getSubstituteChar

public static int getSubstituteChar(char ch,
                                    int form)

createSubstituteString

public static String createSubstituteString(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.


Copyright © 2008 Apache Software Foundation. All Rights Reserved.