/*
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*/
/*
* (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
* (C) Copyright IBM Corp. 1996 - All Rights Reserved
*
* The original version of this source code and documentation is copyrighted
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
* materials are provided under terms of a License Agreement between Taligent
* and Sun. This technology is protected by multiple US and International
* patents. This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.text;
/**
* <code>FieldPosition</code> is a simple class used by <code>Format</code>
* and its subclasses to identify fields in formatted output. Fields can
* be identified in two ways:
* <ul>
* <li>By an integer constant, whose names typically end with
* <code>_FIELD</code>. The constants are defined in the various
* subclasses of <code>Format</code>.
* <li>By a <code>Format.Field</code> constant, see <code>ERA_FIELD</code>
* and its friends in <code>DateFormat</code> for an example.
* </ul>
* <p>
* <code>FieldPosition</code> keeps track of the position of the
* field within the formatted output with two indices: the index
* of the first character of the field and the index of the last
* character of the field.
*
* <p>
* One version of the <code>format</code> method in the various
* <code>Format</code> classes requires a <code>FieldPosition</code>
* object as an argument. You use this <code>format</code> method
* to perform partial formatting or to get information about the
* formatted output (such as the position of a field).
*
* <p>
* If you are interested in the positions of all attributes in the
* formatted string use the <code>Format</code> method
* <code>formatToCharacterIterator</code>.
*
* @author Mark Davis
* @see java.text.Format
*/
public class
FieldPosition {
/**
* Input: Desired field to determine start and end offsets for.
* The meaning depends on the subclass of Format.
*/
int
field = 0;
/**
* Output: End offset of field in text.
* If the field does not occur in the text, 0 is returned.
*/
int
endIndex = 0;
/**
* Output: Start offset of field in text.
* If the field does not occur in the text, 0 is returned.
*/
int
beginIndex = 0;
/**
* Desired field this FieldPosition is for.
*/
private
Format.
Field attribute;
/**
* Creates a FieldPosition object for the given field. Fields are
* identified by constants, whose names typically end with _FIELD,
* in the various subclasses of Format.
*
* @param field the field identifier
* @see java.text.NumberFormat#INTEGER_FIELD
* @see java.text.NumberFormat#FRACTION_FIELD
* @see java.text.DateFormat#YEAR_FIELD
* @see java.text.DateFormat#MONTH_FIELD
*/
public
FieldPosition(int
field) {
this.
field =
field;
}
/**
* Creates a FieldPosition object for the given field constant. Fields are
* identified by constants defined in the various <code>Format</code>
* subclasses. This is equivalent to calling
* <code>new FieldPosition(attribute, -1)</code>.
*
* @param attribute Format.Field constant identifying a field
* @since 1.4
*/
public
FieldPosition(
Format.
Field attribute) {
this(
attribute, -1);
}
/**
* Creates a <code>FieldPosition</code> object for the given field.
* The field is identified by an attribute constant from one of the
* <code>Field</code> subclasses as well as an integer field ID
* defined by the <code>Format</code> subclasses. <code>Format</code>
* subclasses that are aware of <code>Field</code> should give precedence
* to <code>attribute</code> and ignore <code>fieldID</code> if
* <code>attribute</code> is not null. However, older <code>Format</code>
* subclasses may not be aware of <code>Field</code> and rely on
* <code>fieldID</code>. If the field has no corresponding integer
* constant, <code>fieldID</code> should be -1.
*
* @param attribute Format.Field constant identifying a field
* @param fieldID integer constant identifying a field
* @since 1.4
*/
public
FieldPosition(
Format.
Field attribute, int
fieldID) {
this.
attribute =
attribute;
this.
field =
fieldID;
}
/**
* Returns the field identifier as an attribute constant
* from one of the <code>Field</code> subclasses. May return null if
* the field is specified only by an integer field ID.
*
* @return Identifier for the field
* @since 1.4
*/
public
Format.
Field getFieldAttribute() {
return
attribute;
}
/**
* Retrieves the field identifier.
*
* @return the field identifier
*/
public int
getField() {
return
field;
}
/**
* Retrieves the index of the first character in the requested field.
*
* @return the begin index
*/
public int
getBeginIndex() {
return
beginIndex;
}
/**
* Retrieves the index of the character following the last character in the
* requested field.
*
* @return the end index
*/
public int
getEndIndex() {
return
endIndex;
}
/**
* Sets the begin index. For use by subclasses of Format.
*
* @param bi the begin index
* @since 1.2
*/
public void
setBeginIndex(int
bi) {
beginIndex =
bi;
}
/**
* Sets the end index. For use by subclasses of Format.
*
* @param ei the end index
* @since 1.2
*/
public void
setEndIndex(int
ei) {
endIndex =
ei;
}
/**
* Returns a <code>Format.FieldDelegate</code> instance that is associated
* with the FieldPosition. When the delegate is notified of the same
* field the FieldPosition is associated with, the begin/end will be
* adjusted.
*/
Format.
FieldDelegate getFieldDelegate() {
return new
Delegate();
}
/**
* Overrides equals
*/
public boolean
equals(
Object obj)
{
if (
obj == null) return false;
if (!(
obj instanceof
FieldPosition))
return false;
FieldPosition other = (
FieldPosition)
obj;
if (
attribute == null) {
if (
other.
attribute != null) {
return false;
}
}
else if (!
attribute.
equals(
other.
attribute)) {
return false;
}
return (
beginIndex ==
other.
beginIndex
&&
endIndex ==
other.
endIndex
&&
field ==
other.
field);
}
/**
* Returns a hash code for this FieldPosition.
* @return a hash code value for this object
*/
public int
hashCode() {
return (
field << 24) | (
beginIndex << 16) |
endIndex;
}
/**
* Return a string representation of this FieldPosition.
* @return a string representation of this object
*/
public
String toString() {
return
getClass().
getName() +
"[field=" +
field + ",attribute=" +
attribute +
",beginIndex=" +
beginIndex +
",endIndex=" +
endIndex + ']';
}
/**
* Return true if the receiver wants a <code>Format.Field</code> value and
* <code>attribute</code> is equal to it.
*/
private boolean
matchesField(
Format.
Field attribute) {
if (this.
attribute != null) {
return this.
attribute.
equals(
attribute);
}
return false;
}
/**
* Return true if the receiver wants a <code>Format.Field</code> value and
* <code>attribute</code> is equal to it, or true if the receiver
* represents an inteter constant and <code>field</code> equals it.
*/
private boolean
matchesField(
Format.
Field attribute, int
field) {
if (this.
attribute != null) {
return this.
attribute.
equals(
attribute);
}
return (
field == this.
field);
}
/**
* An implementation of FieldDelegate that will adjust the begin/end
* of the FieldPosition if the arguments match the field of
* the FieldPosition.
*/
private class
Delegate implements
Format.
FieldDelegate {
/**
* Indicates whether the field has been encountered before. If this
* is true, and <code>formatted</code> is invoked, the begin/end
* are not updated.
*/
private boolean
encounteredField;
public void
formatted(
Format.
Field attr,
Object value, int
start,
int
end,
StringBuffer buffer) {
if (!
encounteredField &&
matchesField(
attr)) {
setBeginIndex(
start);
setEndIndex(
end);
encounteredField = (
start !=
end);
}
}
public void
formatted(int
fieldID,
Format.
Field attr,
Object value,
int
start, int
end,
StringBuffer buffer) {
if (!
encounteredField &&
matchesField(
attr,
fieldID)) {
setBeginIndex(
start);
setEndIndex(
end);
encounteredField = (
start !=
end);
}
}
}
}