/*
* Copyright (c) 1996, 2002, 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
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*/
/*
* (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
* (C) Copyright IBM Corp. 1996 - 1998 - 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>StringCharacterIterator</code> implements the
* <code>CharacterIterator</code> protocol for a <code>String</code>.
* The <code>StringCharacterIterator</code> class iterates over the
* entire <code>String</code>.
*
* @see CharacterIterator
*/
public final class StringCharacterIterator implements CharacterIterator
{
private String text;
private int begin;
private int end;
// invariant: begin <= pos <= end
private int pos;
/**
* Constructs an iterator with an initial index of 0.
*/
public StringCharacterIterator(String text)
{
this(text, 0);
}
/**
* Constructs an iterator with the specified initial index.
*
* @param text The String to be iterated over
* @param pos Initial iterator position
*/
public StringCharacterIterator(String text, int pos)
{
this(text, 0, text.length(), pos);
}
/**
* Constructs an iterator over the given range of the given string, with the
* index set at the specified position.
*
* @param text The String to be iterated over
* @param begin Index of the first character
* @param end Index of the character following the last character
* @param pos Initial iterator position
*/
public StringCharacterIterator(String text, int begin, int end, int pos) {
if (text == null)
throw new NullPointerException();
this.text = text;
if (begin < 0 || begin > end || end > text.length())
throw new IllegalArgumentException("Invalid substring range");
if (pos < begin || pos > end)
throw new IllegalArgumentException("Invalid position");
this.begin = begin;
this.end = end;
this.pos = pos;
}
/**
* Reset this iterator to point to a new string. This package-visible
* method is used by other java.text classes that want to avoid allocating
* new StringCharacterIterator objects every time their setText method
* is called.
*
* @param text The String to be iterated over
* @since 1.2
*/
public void setText(String text) {
if (text == null)
throw new NullPointerException();
this.text = text;
this.begin = 0;
this.end = text.length();
this.pos = 0;
}
/**
* Implements CharacterIterator.first() for String.
* @see CharacterIterator#first
*/
public char first()
{
pos = begin;
return current();
}
/**
* Implements CharacterIterator.last() for String.
* @see CharacterIterator#last
*/
public char last()
{
if (end != begin) {
pos = end - 1;
} else {
pos = end;
}
return current();
}
/**
* Implements CharacterIterator.setIndex() for String.
* @see CharacterIterator#setIndex
*/
public char setIndex(int p)
{
if (p < begin || p > end)
throw new IllegalArgumentException("Invalid index");
pos = p;
return current();
}
/**
* Implements CharacterIterator.current() for String.
* @see CharacterIterator#current
*/
public char current()
{
if (pos >= begin && pos < end) {
return text.charAt(pos);
}
else {
return DONE;
}
}
/**
* Implements CharacterIterator.next() for String.
* @see CharacterIterator#next
*/
public char next()
{
if (pos < end - 1) {
pos++;
return text.charAt(pos);
}
else {
pos = end;
return DONE;
}
}
/**
* Implements CharacterIterator.previous() for String.
* @see CharacterIterator#previous
*/
public char previous()
{
if (pos > begin) {
pos--;
return text.charAt(pos);
}
else {
return DONE;
}
}
/**
* Implements CharacterIterator.getBeginIndex() for String.
* @see CharacterIterator#getBeginIndex
*/
public int getBeginIndex()
{
return begin;
}
/**
* Implements CharacterIterator.getEndIndex() for String.
* @see CharacterIterator#getEndIndex
*/
public int getEndIndex()
{
return end;
}
/**
* Implements CharacterIterator.getIndex() for String.
* @see CharacterIterator#getIndex
*/
public int getIndex()
{
return pos;
}
/**
* Compares the equality of two StringCharacterIterator objects.
* @param obj the StringCharacterIterator object to be compared with.
* @return true if the given obj is the same as this
* StringCharacterIterator object; false otherwise.
*/
public boolean equals(Object obj)
{
if (this == obj)
return true;
if (!(obj instanceof StringCharacterIterator))
return false;
StringCharacterIterator that = (StringCharacterIterator) obj;
if (hashCode() != that.hashCode())
return false;
if (!text.equals(that.text))
return false;
if (pos != that.pos || begin != that.begin || end != that.end)
return false;
return true;
}
/**
* Computes a hashcode for this iterator.
* @return A hash code
*/
public int hashCode()
{
return text.hashCode() ^ pos ^ begin ^ end;
}
/**
* Creates a copy of this iterator.
* @return A copy of this
*/
public Object clone()
{
try {
StringCharacterIterator other
= (StringCharacterIterator) super.clone();
return other;
}
catch (CloneNotSupportedException e) {
throw new InternalError();
}
}
}