com.google.zxing.common
Class BitSource

java.lang.Object
  com.google.zxing.common.BitSource

public final class BitSource
extends java.lang.Object

This provides an easy abstraction to read bits at a time from a sequence of bytes, where the number of bits read is not often a multiple of 8.

This class is thread-safe but not reentrant. Unless the caller modifies the bytes array it passed in, in which case all bets are off.

Author:

Sean Owen

Constructor Summary

BitSource(byte[] bytes)

Method Summary

int	available()
int	readBits(int numBits)

Methods inherited from class java.lang.Object

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

Constructor Detail

BitSource

public BitSource(byte[] bytes)

Parameters:

bytes - bytes from which this will read bits. Bits will be read from the first byte first. Bits are read within a byte from most-significant to least-significant bit.

Method Detail

readBits

public int readBits(int numBits)

Parameters:

numBits - number of bits to read

Returns:

int representing the bits read. The bits will appear as the least-significant bits of the int

Throws:

java.lang.IllegalArgumentException - if numBits isn't in [1,32]

available

public int available()

Returns:

number of bits that can be read successfully