qbitarray.cpp

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

    \sa clearBit() toggleBit()
*/

/*!
    Clears the bit at position \a index, i.e. sets it to 0.

    \sa setBit(), toggleBit()
*/

void QBitArray::clearBit( uint index )
{
#if defined(QT_CHECK_RANGE)
    if ( index >= size() ) {
	qWarning( "QBitArray::clearBit: Index %d out of range", index );
	return;
    }
#endif
    *(data()+(index>>3)) &= ~(1 << (index & 7));
}

/*!
    Toggles the bit at position \a index.

    If the previous value was 0, the new value will be 1. If the
    previous value was 1, the new value will be 0.

    \sa setBit(), clearBit()
*/

bool QBitArray::toggleBit( uint index )
{
#if defined(QT_CHECK_RANGE)
    if ( index >= size() ) {
	qWarning( "QBitArray::toggleBit: Index %d out of range", index );
	return FALSE;
    }
#endif
    register uchar *p = (uchar *)data() + (index>>3);
    uchar b = (1 << (index & 7));		// bit position
    uchar c = *p & b;				// read bit
    *p ^= b;					// toggle bit
    return c;
}


/*!
    \fn bool QBitArray::at( uint index ) const

    Returns the value (0 or 1) of the bit at position \a index.

    \sa operator[]()
*/

/*!
    \fn QBitVal QBitArray::operator[]( int index )

    Implements the [] operator for bit arrays.

    The returned QBitVal is a context object. It makes it possible to
    get and set a single bit value by its \a index position.

    Example:
    \code
    QBitArray a( 3 );
    a[0] = 0;
    a[1] = 1;
    a[2] = a[0] ^ a[1];
    \endcode

    The functions testBit(), setBit() and clearBit() are faster.

    \sa at()
*/

/*!
    \overload bool QBitArray::operator[]( int index ) const

    Implements the [] operator for constant bit arrays.
*/


/*!
    Performs the AND operation between all bits in this bit array and
    \a a. Returns a reference to this bit array.

    The result has the length of the longest of the two bit arrays,
    with any missing bits (i.e. if one array is shorter than the
    other), taken to be 0.
    \code
    QBitArray a( 3 ), b( 2 );
    a[0] = 1;  a[1] = 0;  a[2] = 1;     // a = [1 0 1]
    b[0] = 1;  b[1] = 0;                // b = [1 0]
    a &= b;                             // a = [1 0 0]
    \endcode

    \sa operator|=(), operator^=(), operator~()
*/

QBitArray &QBitArray::operator&=( const QBitArray &a )
{
    resize( QMAX(size(), a.size()) );
    register uchar *a1 = (uchar *)data();
    register uchar *a2 = (uchar *)a.data();
    int n = QMIN( QByteArray::size(), a.QByteArray::size() );
    int p = QMAX( QByteArray::size(), a.QByteArray::size() ) - n;
    while ( n-- > 0 )
	*a1++ &= *a2++;
    while ( p-- > 0 )
	*a1++ = 0;
    return *this;
}

/*!
    Performs the OR operation between all bits in this bit array and
    \a a. Returns a reference to this bit array.

    The result has the length of the longest of the two bit arrays,
    with any missing bits (i.e. if one array is shorter than the
    other), taken to be 0.
    \code
    QBitArray a( 3 ), b( 2 );
    a[0] = 1;  a[1] = 0;  a[2] = 1;     // a = [1 0 1]
    b[0] = 1;  b[1] = 0;                // b = [1 0]
    a |= b;                             // a = [1 0 1]
    \endcode

    \sa operator&=(), operator^=(), operator~()
*/

QBitArray &QBitArray::operator|=( const QBitArray &a )
{
    resize( QMAX(size(), a.size()) );
    register uchar *a1 = (uchar *)data();
    register uchar *a2 = (uchar *)a.data();
    int n = QMIN( QByteArray::size(), a.QByteArray::size() );
    while ( n-- > 0 )
	*a1++ |= *a2++;
    return *this;
}

/*!
    Performs the XOR operation between all bits in this bit array and
    \a a. Returns a reference to this bit array.

    The result has the length of the longest of the two bit arrays,
    with any missing bits (i.e. if one array is shorter than the
    other), taken to be 0.
    \code
    QBitArray a( 3 ), b( 2 );
    a[0] = 1;  a[1] = 0;  a[2] = 1;     // a = [1 0 1]
    b[0] = 1;  b[1] = 0;                // b = [1 0]
    a ^= b;                             // a = [0 0 1]
    \endcode

    \sa operator&=(), operator|=(), operator~()
*/

QBitArray &QBitArray::operator^=( const QBitArray &a )
{
    resize( QMAX(size(), a.size()) );
    register uchar *a1 = (uchar *)data();
    register uchar *a2 = (uchar *)a.data();
    int n = QMIN( QByteArray::size(), a.QByteArray::size() );
    while ( n-- > 0 )
	*a1++ ^= *a2++;
    return *this;
}

/*!
    Returns a bit array that contains the inverted bits of this bit array.

    Example:
    \code
    QBitArray a( 3 ), b;
    a[0] = 1;  a[1] = 0; a[2] = 1;	// a = [1 0 1]
    b = ~a;				// b = [0 1 0]
    \endcode
*/

QBitArray QBitArray::operator~() const
{
    QBitArray a( size() );
    register uchar *a1 = (uchar *)data();
    register uchar *a2 = (uchar *)a.data();
    int n = QByteArray::size();
    while ( n-- )
	*a2++ = ~*a1++;
    a.pad0();
    return a;
}


/*!
    \relates QBitArray

    Returns the AND result between the bit arrays \a a1 and \a a2.

    The result has the length of the longest of the two bit arrays,
    with any missing bits (i.e. if one array is shorter than the
    other), taken to be 0.

    \sa QBitArray::operator&=()
*/

QBitArray operator&( const QBitArray &a1, const QBitArray &a2 )
{
    QBitArray tmp = a1.copy();
    tmp &= a2;
    return tmp;
}

/*!
    \relates QBitArray

    Returns the OR result between the bit arrays \a a1 and \a a2.

    The result has the length of the longest of the two bit arrays,
    with any missing bits (i.e. if one array is shorter than the
    other), taken to be 0.

    \sa QBitArray::operator|=()
*/

QBitArray operator|( const QBitArray &a1, const QBitArray &a2 )
{
    QBitArray tmp = a1.copy();
    tmp |= a2;
    return tmp;
}

/*!
    \relates QBitArray

    Returns the XOR result between the bit arrays \a a1 and \a a2.

    The result has the length of the longest of the two bit arrays,
    with any missing bits (i.e. if one array is shorter than the
    other), taken to be 0.

    \sa QBitArray::operator^()
*/

QBitArray operator^( const QBitArray &a1, const QBitArray &a2 )
{
    QBitArray tmp = a1.copy();
    tmp ^= a2;
    return tmp;
}


/* \enum QGArray::array_data

  \warning This will be renamed in the next major release of Qt.  Until
  then it is undocumented and we recommend against its use.

  \internal

  ### 3.0 rename ###
  ### 3.0 move it to QGArray? ###
*/


/*!
    \fn QBitArray::array_data * QBitArray::newData()

    \internal

    Returns data specific to QBitArray that extends what QGArray provides.
    QPtrCollection mechanism for allowing extra/different data.
*/


/*!
    \fn void  QBitArray::deleteData ( array_data * d )

    \internal

    Deletes data specific to QBitArray that extended what QGArray provided.

    QPtrCollection mechanism for allowing extra/different data.
*/


/*****************************************************************************
  QBitArray stream functions
 *****************************************************************************/

/*!
    \relates QBitArray

    Writes bit array \a a to stream \a s.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/
#ifndef QT_NO_DATASTREAM
QDataStream &operator<<( QDataStream &s, const QBitArray &a )
{
    Q_UINT32 len = a.size();
    s << len;					// write size of array
    if ( len > 0 )				// write data
	s.writeRawBytes( a.data(), a.QByteArray::size() );
    return s;
}

/*!
    \relates QBitArray

    Reads a bit array into \a a from stream \a s.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator>>( QDataStream &s, QBitArray &a )
{
    Q_UINT32 len;
    s >> len;					// read size of array
    if ( !a.resize( (uint)len ) ) {		// resize array
#if defined(QT_CHECK_NULL)
	qWarning( "QDataStream: Not enough memory to read QBitArray" );
#endif
	len = 0;
    }
    if ( len > 0 )				// read data
	s.readRawBytes( a.data(), a.QByteArray::size() );
    return s;
}

#endif // QT_NO_DATASTREAM