/*
 
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code is distributed in the hope that it will be useful, but WITHOUT
 
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 
* FITNESS FOR A PARTICULAR PURPOSE.
  
See the GNU General Public License
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
* or visit www.oracle.com if you need additional information or have any
 
* questions.
 
*/

/*
 
* (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
     
*
 

     
*
 

     
*
 

     
*
 

     
*/

    
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);
            
}
        
}
    
}
}