/*
 * Copyright (c) 2005, 2020, 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
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/*
 *******************************************************************************
 * Copyright (C) 1996-2009, International Business Machines Corporation and    *
 * others. All Rights Reserved.                                                *
 *******************************************************************************
 */

package jdk_internal.icu.text;

/**
 * <code>ReplaceableString</code> is an adapter class that implements the
 * <code>Replaceable</code> API around an ordinary <code>StringBuffer</code>.
 *
 * <p>
 * <em>Note:</em> This class does not support attributes and is not intended for
 * general use. Most clients will need to implement {@link Replaceable} in their
 * text representation class.
 *
 * <p>
 * Copyright &copy; IBM Corporation 1999. All rights reserved.
 *
 * @see Replaceable
 * @author Alan Liu
 * @stable ICU 2.0
 */
public class ReplaceableString implements Replaceable {

	private StringBuffer buf;

	/**
	 * Construct a new object with the given initial contents.
	 *
	 * @param str initial contents
	 * @stable ICU 2.0
	 */
	public ReplaceableString(String str) {
		buf = new StringBuffer(str);
	}

	/**
	 * Construct a new object using <code>buf</code> for internal storage. The
	 * contents of <code>buf</code> at the time of construction are used as the
	 * initial contents. <em>Note! Modifications to <code>buf</code> will modify
	 * this object, and vice versa.</em>
	 *
	 * @param buf object to be used as internal storage
	 * @stable ICU 2.0
	 */
	public ReplaceableString(StringBuffer buf) {
		this.buf = buf;
	}

	/**
	 * Return the character at the given position in this object.
	 * <code>Replaceable</code> API.
	 *
	 * @param offset offset into the contents, from 0 to <code>length()</code> - 1
	 * @stable ICU 2.0
	 */
	@Override
	public char charAt(int offset) {
		return buf.charAt(offset);
	}

	/**
	 * Copies characters from this object into the destination character array. The
	 * first character to be copied is at index <code>srcStart</code>; the last
	 * character to be copied is at index <code>srcLimit-1</code> (thus the total
	 * number of characters to be copied is <code>srcLimit-srcStart</code>). The
	 * characters are copied into the subarray of <code>dst</code> starting at index
	 * <code>dstStart</code> and ending at index
	 * <code>dstStart + (srcLimit-srcStart) - 1</code>.
	 *
	 * @param srcStart the beginning index to copy, inclusive;
	 *                 {@code 0 <= start <= limit}.
	 * @param srcLimit the ending index to copy, exclusive;
	 *                 {@code start <= limit <= length()}.
	 * @param dst      the destination array.
	 * @param dstStart the start offset in the destination array.
	 * @stable ICU 2.0
	 */
	@Override
	public void getChars(int srcStart, int srcLimit, char dst[], int dstStart) {
		if (srcStart != srcLimit) {
			buf.getChars(srcStart, srcLimit, dst, dstStart);
		}
	}

	/**
	 * Return the number of characters contained in this object.
	 * <code>Replaceable</code> API.
	 *
	 * @stable ICU 2.0
	 */
	@Override
	public int length() {
		return buf.length();
	}
}
