File	Doc	Category	Size	Date	Package
BitField.java	API Doc	Apache Poi 3.0.1	8974	Mon Jan 01 12:39:42 GMT 2007	org.apache.poi.util

BitField

• java.lang.Object

Fields Summary
private final int	_mask
private final int	_shift_count

Constructors Summary
public BitField(int mask) Create a BitField instance param mask the mask specifying which bits apply to this BitField. Bits that are set in this mask are the bits that this BitField operates on _mask = mask; int count = 0; int bit_pattern = mask; if (bit_pattern != 0) { while ((bit_pattern & 1) == 0) { count++; bit_pattern >>= 1; } } _shift_count = count;

Methods Summary
public int	clear(int holder) Clear the bits. param holder the int data containing the bits we're interested in return the value of holder with the specified bits cleared (set to 0) return holder & ~_mask;
public byte	clearByte(byte holder) Clear the bits. param holder the byte data containing the bits we're interested in return the value of holder with the specified bits cleared (set to 0) return ( byte ) clear(holder);
public short	clearShort(short holder) Clear the bits. param holder the short data containing the bits we're interested in return the value of holder with the specified bits cleared (set to 0) return ( short ) clear(holder);
public int	getRawValue(int holder) Obtain the value for the specified BitField, unshifted param holder the int data containing the bits we're interested in return the selected bits return (holder & _mask);
public short	getShortRawValue(short holder) Obtain the value for the specified BitField, unshifted param holder the short data containing the bits we're interested in return the selected bits return ( short ) getRawValue(holder);
public short	getShortValue(short holder) Obtain the value for the specified BitField, appropriately shifted right, as a short. Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits) param holder the short data containing the bits we're interested in return the selected bits, shifted right appropriately return ( short ) getValue(holder);
public int	getValue(int holder) Obtain the value for the specified BitField, appropriately shifted right. Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits) param holder the int data containing the bits we're interested in return the selected bits, shifted right appropriately return getRawValue(holder) >> _shift_count;
public boolean	isAllSet(int holder) Are all of the bits set or not? This is a stricter test than isSet, in that all of the bits in a multi-bit set must be set for this method to return true param holder the int data containing the bits we're interested in return true if all of the bits are set, else false return (holder & _mask) == _mask;
public boolean	isSet(int holder) Is the field set or not? This is most commonly used for a single-bit field, which is often used to represent a boolean value; the results of using it for a multi-bit field is to determine whether *any* of its bits are set param holder the int data containing the bits we're interested in return true if any of the bits are set, else false return (holder & _mask) != 0;
public int	set(int holder) Set the bits. param holder the int data containing the bits we're interested in return the value of holder with the specified bits set to 1 return holder | _mask;
public int	setBoolean(int holder, boolean flag) Set a boolean BitField param holder the int data containing the bits we're interested in param flag indicating whether to set or clear the bits return the value of holder with the specified bits set or cleared return flag ? set(holder) : clear(holder);
public byte	setByte(byte holder) Set the bits. param holder the byte data containing the bits we're interested in return the value of holder with the specified bits set to 1 return ( byte ) set(holder);
public byte	setByteBoolean(byte holder, boolean flag) Set a boolean BitField param holder the byte data containing the bits we're interested in param flag indicating whether to set or clear the bits return the value of holder with the specified bits set or cleared return flag ? setByte(holder) : clearByte(holder);
public short	setShort(short holder) Set the bits. param holder the short data containing the bits we're interested in return the value of holder with the specified bits set to 1 return ( short ) set(holder);
public short	setShortBoolean(short holder, boolean flag) Set a boolean BitField param holder the short data containing the bits we're interested in param flag indicating whether to set or clear the bits return the value of holder with the specified bits set or cleared return flag ? setShort(holder) : clearShort(holder);
public short	setShortValue(short holder, short value) Replace the bits with new values. param holder the short data containing the bits we're interested in param value the new value for the specified bits return the value of holder with the bits from the value parameter replacing the old bits return ( short ) setValue(holder, value);
public int	setValue(int holder, int value) Replace the bits with new values. param holder the int data containint the bits we're interested in param value the new value for the specified bits return the value of holder with the bits from the value parameter replacing the old bits return (holder & ~_mask) | ((value << _shift_count) & _mask);