/*
* @(#)AttributedCharacterIterator.java 1.32 04/05/05
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.text;
import java.io.InvalidObjectException;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* An AttributedCharacterIterator allows iteration through both text and
* related attribute information.
*
* <p>
* An attribute is a key/value pair, identified by the key. No two
* attributes on a given character can have the same key.
*
* <p>The values for an attribute are immutable, or must not be mutated
* by clients or storage. They are always passed by reference, and not
* cloned.
*
* <p>A <em>run with respect to an attribute</em> is a maximum text range for
* which:
* <ul>
* <li>the attribute is undefined or null for the entire range, or
* <li>the attribute value is defined and has the same non-null value for the
* entire range.
* </ul>
*
* <p>A <em>run with respect to a set of attributes</em> is a maximum text range for
* which this condition is met for each member attribute.
*
* <p>The returned indexes are limited to the range of the iterator.
*
* <p>The returned attribute information is limited to runs that contain
* the current character.
*
* <p>
* Attribute keys are instances of AttributedCharacterIterator.Attribute and its
* subclasses, such as java.awt.font.TextAttribute.
*
* @see AttributedCharacterIterator.Attribute
* @see java.awt.font.TextAttribute
* @see AttributedString
* @see Annotation
* @since 1.2
*/
public interface AttributedCharacterIterator extends CharacterIterator {
/**
* Defines attribute keys that are used to identify text attributes. These
* keys are used in AttributedCharacterIterator and AttributedString.
* @see AttributedCharacterIterator
* @see AttributedString
* @since 1.2
*/
public static class Attribute implements Serializable {
/**
* The name of this Attribute. The name is used primarily by readResolve
* to look up the corresponding predefined instance when deserializing
* an instance.
* @serial
*/
private String name;
// table of all instances in this class, used by readResolve
private static final Map instanceMap = new HashMap(7);
/**
* Constructs an Attribute with the given name.
*/
protected Attribute(String name) {
this.name = name;
if (this.getClass() == Attribute.class) {
instanceMap.put(name, this);
}
}
/**
* Compares two objects for equality. This version only returns true
* for <code>x.equals(y)</code> if <code>x</code> and <code>y</code> refer
* to the same object, and guarantees this for all subclasses.
*/
public final boolean equals(Object obj) {
return super.equals(obj);
}
/**
* Returns a hash code value for the object. This version is identical to
* the one in Object, but is also final.
*/
public final int hashCode() {
return super.hashCode();
}
/**
* Returns a string representation of the object. This version returns the
* concatenation of class name, "(", a name identifying the attribute and ")".
*/
public String toString() {
return getClass().getName() + "(" + name + ")";
}
/**
* Returns the name of the attribute.
*/
protected String getName() {
return name;
}
/**
* Resolves instances being deserialized to the predefined constants.
*/
protected Object readResolve() throws InvalidObjectException {
if (this.getClass() != Attribute.class) {
throw new InvalidObjectException("subclass didn't correctly implement readResolve");
}
Attribute instance = (Attribute) instanceMap.get(getName());
if (instance != null) {
return instance;
} else {
throw new InvalidObjectException("unknown attribute name");
}
}
/**
* Attribute key for the language of some text.
* <p> Values are instances of Locale.
* @see java.util.Locale
*/
public static final Attribute LANGUAGE = new Attribute("language");
/**
* Attribute key for the reading of some text. In languages where the written form
* and the pronunciation of a word are only loosely related (such as Japanese),
* it is often necessary to store the reading (pronunciation) along with the
* written form.
* <p>Values are instances of Annotation holding instances of String.
* @see Annotation
* @see java.lang.String
*/
public static final Attribute READING = new Attribute("reading");
/**
* Attribute key for input method segments. Input methods often break
* up text into segments, which usually correspond to words.
* <p>Values are instances of Annotation holding a null reference.
* @see Annotation
*/
public static final Attribute INPUT_METHOD_SEGMENT = new Attribute("input_method_segment");
// make sure the serial version doesn't change between compiler versions
private static final long serialVersionUID = -9142742483513960612L;
};
/**
* Returns the index of the first character of the run
* with respect to all attributes containing the current character.
*/
public int getRunStart();
/**
* Returns the index of the first character of the run
* with respect to the given attribute containing the current character.
*/
public int getRunStart(Attribute attribute);
/**
* Returns the index of the first character of the run
* with respect to the given attributes containing the current character.
*/
public int getRunStart(Set<? extends Attribute> attributes);
/**
* Returns the index of the first character following the run
* with respect to all attributes containing the current character.
*/
public int getRunLimit();
/**
* Returns the index of the first character following the run
* with respect to the given attribute containing the current character.
*/
public int getRunLimit(Attribute attribute);
/**
* Returns the index of the first character following the run
* with respect to the given attributes containing the current character.
*/
public int getRunLimit(Set<? extends Attribute> attributes);
/**
* Returns a map with the attributes defined on the current
* character.
*/
public Map<Attribute,Object> getAttributes();
/**
* Returns the value of the named attribute for the current character.
* Returns null if the attribute is not defined.
* @param attribute the key of the attribute whose value is requested.
*/
public Object getAttribute(Attribute attribute);
/**
* Returns the keys of all attributes defined on the
* iterator's text range. The set is empty if no
* attributes are defined.
*/
public Set<Attribute> getAllAttributeKeys();
};
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