| /* |
| * QR Code generator library (Java) |
| * |
| * Copyright (c) Project Nayuki. (MIT License) |
| * https://www.nayuki.io/page/qr-code-generator-library |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy of |
| * this software and associated documentation files (the "Software"), to deal in |
| * the Software without restriction, including without limitation the rights to |
| * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of |
| * the Software, and to permit persons to whom the Software is furnished to do so, |
| * subject to the following conditions: |
| * - The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * - The Software is provided "as is", without warranty of any kind, express or |
| * implied, including but not limited to the warranties of merchantability, |
| * fitness for a particular purpose and noninfringement. In no event shall the |
| * authors or copyright holders be liable for any claim, damages or other |
| * liability, whether in an action of contract, tort or otherwise, arising from, |
| * out of or in connection with the Software or the use or other dealings in the |
| * Software. |
| */ |
| |
| package io.nayuki.qrcodegen; |
| |
| import java.util.BitSet; |
| import java.util.Objects; |
| |
| |
| /** |
| * An appendable sequence of bits (0's and 1's). |
| */ |
| public final class BitBuffer implements Cloneable { |
| |
| /*---- Fields ----*/ |
| |
| private BitSet data; |
| |
| private int bitLength; |
| |
| |
| |
| /*---- Constructor ----*/ |
| |
| /** |
| * Constructs an empty bit buffer (length 0). |
| */ |
| public BitBuffer() { |
| data = new BitSet(); |
| bitLength = 0; |
| } |
| |
| |
| |
| /*---- Methods ----*/ |
| |
| /** |
| * Returns the length of this sequence, which is a non-negative value. |
| * @return the length of this sequence |
| */ |
| public int bitLength() { |
| return bitLength; |
| } |
| |
| |
| /** |
| * Returns the bit at the specified index, yielding 0 or 1. |
| * @param index the index to get the bit at |
| * @return the bit at the specified index |
| * @throws IndexOutOfBoundsException if index < 0 or index ≥ bitLength |
| */ |
| public int getBit(int index) { |
| if (index < 0 || index >= bitLength) |
| throw new IndexOutOfBoundsException(); |
| return data.get(index) ? 1 : 0; |
| } |
| |
| |
| /** |
| * Packs this buffer's bits into bytes in big endian, |
| * padding with '0' bit values, and returns the new array. |
| * @return this sequence as a new array of bytes (not {@code null}) |
| */ |
| public byte[] getBytes() { |
| byte[] result = new byte[(bitLength + 7) / 8]; |
| for (int i = 0; i < bitLength; i++) |
| result[i >>> 3] |= data.get(i) ? 1 << (7 - (i & 7)) : 0; |
| return result; |
| } |
| |
| |
| /** |
| * Appends the specified number of low bits of the specified value |
| * to this sequence. Requires 0 ≤ val < 2<sup>len</sup>. |
| * @param val the value to append |
| * @param len the number of low bits in the value to take |
| */ |
| public void appendBits(int val, int len) { |
| if (len < 0 || len > 31 || val >>> len != 0) |
| throw new IllegalArgumentException("Value out of range"); |
| for (int i = len - 1; i >= 0; i--, bitLength++) // Append bit by bit |
| data.set(bitLength, ((val >>> i) & 1) != 0); |
| } |
| |
| |
| /** |
| * Appends the bit data of the specified segment to this bit buffer. |
| * @param seg the segment whose data to append (not {@code null}) |
| * @throws NullPointerException if the segment is {@code null} |
| */ |
| public void appendData(QrSegment seg) { |
| Objects.requireNonNull(seg); |
| BitBuffer bb = seg.data; |
| for (int i = 0; i < bb.bitLength; i++, bitLength++) // Append bit by bit |
| data.set(bitLength, bb.data.get(i)); |
| } |
| |
| |
| /** |
| * Returns a copy of this bit buffer object. |
| * @return a copy of this bit buffer object |
| */ |
| public BitBuffer clone() { |
| try { |
| BitBuffer result = (BitBuffer)super.clone(); |
| result.data = (BitSet)result.data.clone(); |
| return result; |
| } catch (CloneNotSupportedException e) { |
| throw new AssertionError(e); |
| } |
| } |
| |
| } |