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 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.sun.org.apache.xerces.internal.xni;

/**

 * This class is used as a structure to pass text contained in the underlying

 * character buffer of the scanner. The offset and length fields allow the

 * buffer to be re-used without creating new character arrays.

 * <p>

 * <strong>Note:</strong> Methods that are passed an XMLString structure

 * should consider the contents read-only and not make any modifications

 * to the contents of the buffer. The method receiving this structure

 * should also not modify the offset and length if this structure (or

 * the values of this structure) are passed to another method.

 * <p>

 * <strong>Note:</strong> Methods that are passed an XMLString structure

 * are required to copy the information out of the buffer if it is to be

 * saved for use beyond the scope of the method. The contents of the

 * structure are volatile and the contents of the character buffer cannot

 * be assured once the method that is passed this structure returns.

 * Therefore, methods passed this structure should not save any reference

 * to the structure or the character array contained in the structure.

 *

 * @author Eric Ye, IBM

 * @author Andy Clark, IBM

 *

 */

public class XMLString {

    //

    // Data

    //

    /** The character array. */

    public char[] ch;

    /** The offset into the character array. */

    public int offset;

    /** The length of characters from the offset. */

    public int length;

    //

    // Constructors

    //

    /** Default constructor. */

    public XMLString() {

    } // <init>()

    /**

     * Constructs an XMLString structure preset with the specified

     * values.

     *

     * @param ch     The character array.

     * @param offset The offset into the character array.

     * @param length The length of characters from the offset.

     */

    public XMLString(char[] ch, int offset, int length) {

        setValues(ch, offset, length);

    } // <init>(char[],int,int)

    /**

     * Constructs an XMLString structure with copies of the values in

     * the given structure.

     * <p>

     * <strong>Note:</strong> This does not copy the character array;

     * only the reference to the array is copied.

     *

     * @param string The XMLString to copy.

     */

    public XMLString(XMLString string) {

        setValues(string);

    } // <init>(XMLString)

    //

    // Public methods

    //

    /**

     * Initializes the contents of the XMLString structure with the

     * specified values.

     *

     * @param ch     The character array.

     * @param offset The offset into the character array.

     * @param length The length of characters from the offset.

     */

    public void setValues(char[] ch, int offset, int length) {

        this.ch = ch;

        this.offset = offset;

        this.length = length;

    } // setValues(char[],int,int)

    /**

     * Initializes the contents of the XMLString structure with copies

     * of the given string structure.

     * <p>

     * <strong>Note:</strong> This does not copy the character array;

     * only the reference to the array is copied.

     *

     * @param s

     */

    public void setValues(XMLString s) {

        setValues(s.ch, s.offset, s.length);

    } // setValues(XMLString)

    /** Resets all of the values to their defaults. */

    public void clear() {

        this.ch = null;

        this.offset = 0;

        this.length = -1;

    } // clear()

    /**

     * Returns true if the contents of this XMLString structure and

     * the specified array are equal.

     *

     * @param ch     The character array.

     * @param offset The offset into the character array.

     * @param length The length of characters from the offset.

     */

    public boolean equals(char[] ch, int offset, int length) {

        if (ch == null) {

            return false;

        }

        if (this.length != length) {

            return false;

        }

        for (int i=0; i<length; i++) {

            if (this.ch[this.offset+i] != ch[offset+i] ) {

                return false;

            }

        }

        return true;

    } // equals(char[],int,int):boolean

    /**

     * Returns true if the contents of this XMLString structure and

     * the specified string are equal.

     *

     * @param s The string to compare.

     */

    public boolean equals(String s) {

        if (s == null) {

            return false;

        }

        if ( length != s.length() ) {

            return false;

        }

        // is this faster than call s.toCharArray first and compare the

        // two arrays directly, which will possibly involve creating a

        // new char array object.

        for (int i=0; i<length; i++) {

            if (ch[offset+i] != s.charAt(i)) {

                return false;

            }

        }

        return true;

    } // equals(String):boolean

    //

    // Object methods

    //

    /** Returns a string representation of this object. */

    public String toString() {

        return length > 0 ? new String(ch, offset, length) : "";

    } // toString():String

} // class XMLString