This interface extends CharacterIterator for working with text that is marked up with attributes in some way. It defines an inner class, AttributedCharaterIterator.Attribute, that represents attribute keys. AttributedCharacterIterator defines methods for querying the attribute keys, values, and runs for the text being iterated over. getAllAttributeKeys( ) returns the Set of all attribute keys that appear anywhere in the text. getAttributes( ) returns a Map that contains the attribute keys and values that apply to the current character. getAttribute( ) returns the value associated with the specified attribute key for the current character.

geTRunStart( ) and getrunLimit( ) return the index of the first and last characters in a run. A run is a string of adjacent characters for which an attribute has the same value or is undefined (i.e., has a value of null). A run can also be defined for a set of attributes, in which case it is a set of adjacent characters for which all attributes in the set hold a constant value (which may include null). Programs that process or display attributed text must usually work with it one run at a time. The no-argument versions of getrunStart( ) and geTRunLimit( ) return the start and end of the run that includes the current character and all attributes that are applied to the current character. The other versions of these methods return the start and end of the run of the specified attribute or set of attributes that includes the current character.

The AttributedString class provides a simple way to define short strings of attributed text and obtain an AttributedCharacterIterator over them. Most applications that process attributed text are working with attributed text from specialized data sources, stored in some specialized data format, so they need to define a custom implementation of AttributedCharacterIterator.

Figure 15-1. java.text.AttributedCharacterIterator

public interface AttributedCharacterIterator extends CharacterIterator {
// Nested Types
     public static class Attribute implements Serializable; 
// Public Instance Methods
     java.util.Set<AttributedCharacterIterator.Attribute> 
        getAllAttributeKeys( );  
     Object getAttribute(AttributedCharacterIterator.Attribute attribute);  
     java.util.Map<AttributedCharacterIterator.Attribute,Object> 
        getAttributes( );  
     int getRunLimit( );  
     int getRunLimit(java.util.Set<? extends AttributedCharacterIterator.
        Attribute> attributes);  
     int getRunLimit(AttributedCharacterIterator.Attribute attribute);  
     int getRunStart( );  
     int getRunStart(AttributedCharacterIterator.Attribute attribute);  
     int getRunStart(java.util.Set<? extends AttributedCharacterIterator.
        Attribute> attributes);  
}

Passed To

AttributedString.AttributedString( ), Bidi.Bidi( )

Returned By

AttributedString.getIterator( ), DecimalFormat.formatToCharacterIterator( ), Format.formatToCharacterIterator( ), MessageFormat.formatToCharacterIterator( ), SimpleDateFormat.formatToCharacterIterator( )