Package io.nayuki.qrcodegen

Class BitBuffer

  • All Implemented Interfaces:
    java.lang.Cloneable
    public final class BitBuffer
extends java.lang.Object
implements java.lang.Cloneable
    An appendable sequence of bits (0s and 1s). Mainly used by QrSegment.

    • Constructor Summary

      Constructors 
      Constructor Description
      BitBuffer()
      Constructs an empty bit buffer (length 0).

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void appendBits​(int val, int len)
      Appends the specified number of low-order bits of the specified value to this buffer.
      void appendData​(BitBuffer bb)
      Appends the content of the specified bit buffer to this buffer.
      int bitLength()
      Returns the length of this sequence, which is a non-negative value.
      BitBuffer clone()
      Returns a new copy of this buffer.
      int getBit​(int index)
      Returns the bit at the specified index, yielding 0 or 1.

      • Methods inherited from class java.lang.Object

        equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • BitBuffer

        public BitBuffer()
        Constructs an empty bit buffer (length 0).

    • Method Detail

      • bitLength

        public int bitLength()
        Returns the length of this sequence, which is a non-negative value.
        Returns:
        the length of this sequence

      • getBit

        public int getBit​(int index)
        Returns the bit at the specified index, yielding 0 or 1.
        Parameters:
        index - the index to get the bit at
        Returns:
        the bit at the specified index
        Throws:
        java.lang.IndexOutOfBoundsException - if index < 0 or index ≥ bitLength

      • appendBits

        public void appendBits​(int val,
                       int len)
        Appends the specified number of low-order bits of the specified value to this buffer. Requires 0 ≤ len ≤ 31 and 0 ≤ val < 2len.
        Parameters:
        val - the value to append
        len - the number of low-order bits in the value to take
        Throws:
        java.lang.IllegalArgumentException - if the value or number of bits is out of range
        java.lang.IllegalStateException - if appending the data would make bitLength exceed Integer.MAX_VALUE

      • appendData

        public void appendData​(BitBuffer bb)
        Appends the content of the specified bit buffer to this buffer.
        Parameters:
        bb - the bit buffer whose data to append (not null)
        Throws:
        java.lang.NullPointerException - if the bit buffer is null
        java.lang.IllegalStateException - if appending the data would make bitLength exceed Integer.MAX_VALUE

      • clone

        public BitBuffer clone()
        Returns a new copy of this buffer.
        Overrides:
        clone in class java.lang.Object
        Returns:
        a new copy of this buffer (not null)