1 /*
   2  * Copyright (c) 1999, 2001, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.imageio.stream;
  27 
  28 /**
  29  * A class representing a mutable reference to an array of bytes and
  30  * an offset and length within that array.  <code>IIOByteBuffer</code>
  31  * is used by <code>ImageInputStream</code> to supply a sequence of bytes
  32  * to the caller, possibly with fewer copies than using the conventional
  33  * <code>read</code> methods that take a user-supplied byte array.
  34  *
  35  * <p> The byte array referenced by an <code>IIOByteBuffer</code> will
  36  * generally be part of an internal data structure belonging to an
  37  * <code>ImageReader</code> implementation; its contents should be
  38  * considered read-only and must not be modified.
  39  *
  40  */
  41 public class IIOByteBuffer {
  42 
  43     private byte[] data;
  44 
  45     private int offset;
  46 
  47     private int length;
  48 
  49     /**
  50      * Constructs an <code>IIOByteBuffer</code> that references a
  51      * given byte array, offset, and length.
  52      *
  53      * @param data a byte array.
  54      * @param offset an int offset within the array.
  55      * @param length an int specifying the length of the data of
  56      * interest within byte array, in bytes.
  57      */
  58     public IIOByteBuffer(byte[] data, int offset, int length) {
  59         this.data = data;
  60         this.offset = offset;
  61         this.length = length;
  62     }
  63 
  64     /**
  65      * Returns a reference to the byte array.  The returned value should
  66      * be treated as read-only, and only the portion specified by the
  67      * values of <code>getOffset</code> and <code>getLength</code> should
  68      * be used.
  69      *
  70      * @return a byte array reference.
  71      *
  72      * @see #getOffset
  73      * @see #getLength
  74      * @see #setData
  75      */
  76     public byte[] getData() {
  77         return data;
  78     }
  79 
  80     /**
  81      * Updates the array reference that will be returned by subsequent calls
  82      * to the <code>getData</code> method.
  83      *
  84      * @param data a byte array reference containing the new data value.
  85      *
  86      * @see #getData
  87      */
  88     public void setData(byte[] data) {
  89         this.data = data;
  90     }
  91 
  92     /**
  93      * Returns the offset within the byte array returned by
  94      * <code>getData</code> at which the data of interest start.
  95      *
  96      * @return an int offset.
  97      *
  98      * @see #getData
  99      * @see #getLength
 100      * @see #setOffset
 101      */
 102     public int getOffset() {
 103         return offset;
 104     }
 105 
 106     /**
 107      * Updates the value that will be returned by subsequent calls
 108      * to the <code>getOffset</code> method.
 109      *
 110      * @param offset an int containing the new offset value.
 111      *
 112      * @see #getOffset
 113      */
 114     public void setOffset(int offset) {
 115         this.offset = offset;
 116     }
 117 
 118     /**
 119      * Returns the length of the data of interest within the byte
 120      * array returned by <code>getData</code>.
 121      *
 122      * @return an int length.
 123      *
 124      * @see #getData
 125      * @see #getOffset
 126      * @see #setLength
 127      */
 128     public int getLength() {
 129         return length;
 130     }
 131 
 132     /**
 133      * Updates the value that will be returned by subsequent calls
 134      * to the <code>getLength</code> method.
 135      *
 136      * @param length an int containing the new length value.
 137      *
 138      * @see #getLength
 139      */
 140     public void setLength(int length) {
 141         this.length = length;
 142     }
 143 }