com.google.zxing.common
Class BitArray

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

public final class BitArray
extends java.lang.Object

A simple, fast array of bits, represented compactly by an array of ints internally.

Author:

Sean Owen

Field Summary

int[]	bits
int	size

Constructor Summary

BitArray(int size)

Method Summary

void	clear() Clears all bits (sets to false).
void	flip(int i) Flips bit i.
boolean	get(int i)
int[]	getBitArray()
int	getSize()
boolean	isRange(int start, int end, boolean value) Efficient method to check if a range of bits is set, or not set.
void	reverse() Reverses all bits in the array.
void	set(int i) Sets bit i.
void	setBulk(int i, int newBits) Sets a block of 32 bits, starting at bit i.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

bits

public int[] bits

size

public final int size

Constructor Detail

BitArray

public BitArray(int size)

Method Detail

getSize

public int getSize()

get

public boolean get(int i)

Parameters:

i - bit to get

Returns:

true iff bit i is set

set

public void set(int i)

Sets bit i.

Parameters:

i - bit to set

flip

public void flip(int i)

Flips bit i.

Parameters:

i - bit to set

setBulk

public void setBulk(int i,
                    int newBits)

Sets a block of 32 bits, starting at bit i.

Parameters:

i - first bit to set

newBits - the new value of the next 32 bits. Note again that the least-significant bit corresponds to bit i, the next-least-significant to i+1, and so on.

clear

public void clear()

Clears all bits (sets to false).

isRange

public boolean isRange(int start,
                       int end,
                       boolean value)

Efficient method to check if a range of bits is set, or not set.

Parameters:

start - start of range, inclusive.

end - end of range, exclusive

value - if true, checks that bits in range are set, otherwise checks that they are not set

Returns:

true iff all bits are set or not set in range, according to value argument

Throws:

java.lang.IllegalArgumentException - if end is less than or equal to start

getBitArray

public int[] getBitArray()

Returns:

underlying array of ints. The first element holds the first 32 bits, and the least significant bit is bit 0.

reverse

public void reverse()

Reverses all bits in the array.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object