qtextstream.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。

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#include "qtextstream.h"

#ifndef QT_NO_TEXTSTREAM
#ifndef QT_NO_TEXTCODEC
#include "qtextcodec.h"
#endif
#include "qregexp.h"
#include "qbuffer.h"
#include "qfile.h"
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <locale.h>

#if defined(Q_OS_WIN32)
#include <windows.h>
#endif

/*!
    \class QTextStream qtextstream.h
    \reentrant
    \brief The QTextStream class provides basic functions for reading
    and writing text using a QIODevice.

    \ingroup io
    \ingroup text
    \mainclass

    The text stream class has a functional interface that is very
    similar to that of the standard C++ iostream class.

    Qt provides several global functions similar to the ones in iostream:
    \table
    \header \i Function \i Meaning
    \row \i bin \i sets the QTextStream to read/write binary numbers
    \row \i oct \i sets the QTextStream to read/write octal numbers
    \row \i dec \i sets the QTextStream to read/write decimal numbers
    \row \i hex \i sets the QTextStream to read/write hexadecimal numbers
    \row \i endl \i forces a line break
    \row \i flush \i forces the QIODevice to flush any buffered data
    \row \i ws \i eats any available whitespace (on input)
    \row \i reset \i resets the QTextStream to its default mode (see reset())
    \row \i qSetW(int) \i sets the \link width() field width \endlink
    to the given argument
    \row \i qSetFill(int) \i sets the \link fill() fill character
    \endlink to the given argument
    \row \i qSetPrecision(int) \i sets the \link precision() precision
    \endlink to the given argument
    \endtable

    \warning By default QTextStream will automatically detect whether
    integers in the stream are in decimal, octal, hexadecimal or
    binary format when reading from the stream. In particular, a
    leading '0' signifies octal, i.e. the sequence "0100" will be
    interpreted as 64.

    The QTextStream class reads and writes text; it is not appropriate
    for dealing with binary data (but QDataStream is).

    By default, output of Unicode text (i.e. QString) is done using
    the local 8-bit encoding. This can be changed using the
    setEncoding() method. For input, the QTextStream will auto-detect
    standard Unicode "byte order marked" text files; otherwise the
    local 8-bit encoding is used.

    The QIODevice is set in the constructor, or later using
    setDevice(). If the end of the input is reached atEnd() returns
    TRUE. Data can be read into variables of the appropriate type
    using the operator>>() overloads, or read in its entirety into a
    single string using read(), or read a line at a time using
    readLine(). Whitespace can be skipped over using skipWhiteSpace().
    You can set flags for the stream using flags() or setf(). The
    stream also supports width(), precision() and fill(); use reset()
    to reset the defaults.

    \sa QDataStream
*/

/*!
    \enum QTextStream::Encoding

    \value Locale
    \value Latin1
    \value Unicode
    \value UnicodeNetworkOrder
    \value UnicodeReverse
    \value RawUnicode
    \value UnicodeUTF8

    See setEncoding() for an explanation of the encodings.
*/

/*
  \class QTSManip

  \brief The QTSManip class is an internal helper class for the
  QTextStream.

  It is generally a very bad idea to use this class directly in
  application programs.

  \internal

  This class makes it possible to give the QTextStream function objects
  with arguments, like this:
  \code
    QTextStream cout( stdout, IO_WriteOnly );
    cout << setprecision( 8 );		// QTSManip used here!
    cout << 3.14159265358979323846;
  \endcode

  The setprecision() function returns a QTSManip object.
  The QTSManip object contains a pointer to a member function in
  QTextStream and an integer argument.
  When serializing a QTSManip into a QTextStream, the function
  is executed with the argument.
*/

/*! \fn QTSManip::QTSManip( QTSMFI m, int a )

  Constructs a QTSManip object which will call \a m (a member function
  in QTextStream which accepts a single int) with argument \a a when
  QTSManip::exec() is called. Used internally in e.g. endl:

  \code
    s << "some text" << endl << "more text";
  \endcode
*/

/*! \fn void QTSManip::exec( QTextStream& s )

  Calls the member function specified in the constructor, for object
  \a s. Used internally in e.g. endl:

  \code
    s << "some text" << endl << "more text";
  \endcode
*/


/*****************************************************************************
  QTextStream member functions
 *****************************************************************************/

#if defined(QT_CHECK_STATE)
#undef  CHECK_STREAM_PRECOND
#define CHECK_STREAM_PRECOND  if ( !dev ) {				\
				qWarning( "QTextStream: No device" );	\
				return *this; }
#else
#define CHECK_STREAM_PRECOND
#endif


#define I_SHORT		0x0010
#define I_INT		0x0020
#define I_LONG		0x0030
#define I_TYPE_MASK	0x00f0

#define I_BASE_2	QTS::bin
#define I_BASE_8	QTS::oct
#define I_BASE_10	QTS::dec
#define I_BASE_16	QTS::hex
#define I_BASE_MASK	(QTS::bin | QTS::oct | QTS::dec | QTS::hex)

#define I_SIGNED	0x0100
#define I_UNSIGNED	0x0200
#define I_SIGN_MASK	0x0f00


static const QChar QEOF = QChar((ushort)0xffff); //guaranteed not to be a character.
static const uint getline_buf_size = 256; // bufsize used by ts_getline()

const int QTextStream::basefield   = I_BASE_MASK;
const int QTextStream::adjustfield = ( QTextStream::left |
				       QTextStream::right |
				       QTextStream::internal );
const int QTextStream::floatfield  = ( QTextStream::scientific |
				       QTextStream::fixed );


class QTextStreamPrivate {
public:
#ifndef QT_NO_TEXTCODEC
    QTextStreamPrivate()
	: decoder( 0 ), encoder( 0 ), sourceType( NotSet ) { }
    ~QTextStreamPrivate() {
	delete decoder;
	delete encoder;
    }
    QTextDecoder *decoder;
    QTextEncoder *encoder;
#else
    QTextStreamPrivate() : sourceType( NotSet ) { }
    ~QTextStreamPrivate() { }
#endif
    QString ungetcBuf;

    enum SourceType { NotSet, IODevice, String, ByteArray, File };
    SourceType sourceType;
};


// skips whitespace and returns the first non-whitespace character
QChar QTextStream::eat_ws()
{
    QChar c;
    do { c = ts_getc(); } while ( c != QEOF && ts_isspace(c) );
    return c;
}

void QTextStream::init()
{
    // ### ungetcBuf = QEOF;
    dev = 0;
    owndev = FALSE;
    mapper = 0;
    d = new QTextStreamPrivate;
    doUnicodeHeader = TRUE; // autodetect
    latin1 = TRUE; // should use locale?
    internalOrder = QChar::networkOrdered();
    networkOrder = TRUE;
}

/*!
    Constructs a data stream that has no IO device.
*/

QTextStream::QTextStream()
{
    init();
    setEncoding( Locale );
    reset();
    d->sourceType = QTextStreamPrivate::NotSet;
}

/*!
    Constructs a text stream that uses the IO device \a iod.
*/

QTextStream::QTextStream( QIODevice *iod )
{
    init();
    setEncoding( Locale );
    dev = iod;
    reset();
    d->sourceType = QTextStreamPrivate::IODevice;
}

// TODO: use special-case handling of this case in QTextStream, and
//	 simplify this class to only deal with QChar or QString data.
class QStringBuffer : public QIODevice {
public:
    QStringBuffer( QString* str );
    ~QStringBuffer();
    bool  open( int m );
    void  close();
    void  flush();
    Offset  size() const;
    Offset  at()   const;
    bool  at( Offset pos );
    Q_LONG readBlock( char *p, Q_ULONG len );
    Q_LONG writeBlock( const char *p, Q_ULONG len );
    int   getch();
    int   putch( int ch );
    int   ungetch( int ch );
protected:
    QString* s;

private:
    QStringBuffer( const QStringBuffer & );
    QStringBuffer &operator=( const QStringBuffer & );
};


QStringBuffer::QStringBuffer( QString* str )
{
    s = str;
}

QStringBuffer::~QStringBuffer()
{
}


bool QStringBuffer::open( int m )
{
    if ( !s ) {
#if defined(QT_CHECK_STATE)
	qWarning( "QStringBuffer::open: No string" );
#endif
	return FALSE;
    }
    if ( isOpen() ) {
#if defined(QT_CHECK_STATE)
	qWarning( "QStringBuffer::open: Buffer already open" );
#endif
	return FALSE;
    }
    setMode( m );
    if ( m & IO_Truncate )
	s->truncate( 0 );

    if ( m & IO_Append ) {
	ioIndex = s->length()*sizeof(QChar);
    } else {
	ioIndex = 0;
    }
    setState( IO_Open );
    resetStatus();
    return TRUE;
}

void QStringBuffer::close()
{
    if ( isOpen() ) {
	setFlags( IO_Direct );
	ioIndex = 0;
    }
}

void QStringBuffer::flush()
{
}

QIODevice::Offset QStringBuffer::size() const
{
    return s ? s->length()*sizeof(QChar) : 0;
}

QIODevice::Offset  QStringBuffer::at()   const
{
    return ioIndex;
}

bool QStringBuffer::at( Offset pos )
{
#if defined(QT_CHECK_STATE)
    if ( !isOpen() ) {
	qWarning( "QStringBuffer::at: Buffer is not open" );
	return FALSE;
    }
#endif
    if ( pos >= s->length()*2 ) {
#if defined(QT_CHECK_RANGE)
#if defined(QT_LARGEFILE_SUPPORT) && defined(QT_ABI_64BITOFFSET)
	qWarning( "QStringBuffer::at: Index %llu out of range", pos );
#else
	qWarning( "QStringBuffer::at: Index %lu out of range", pos );
#endif
#endif
	return FALSE;
    }
    ioIndex = pos;
    return TRUE;
}


Q_LONG QStringBuffer::readBlock( char *p, Q_ULONG len )
{
#if defined(QT_CHECK_STATE)
    Q_CHECK_PTR( p );
    if ( !isOpen() ) {
	qWarning( "QStringBuffer::readBlock: Buffer not open" );
	return -1;
    }
    if ( !isReadable() ) {
	qWarning( "QStringBuffer::readBlock: Read operation not permitted" );
	return -1;
    }
#endif
    if ( ioIndex + len > s->length()*sizeof(QChar) ) {
	// overflow
	if ( (uint)ioIndex >= s->length()*sizeof(QChar) ) {
	    setStatus( IO_ReadError );
	    return -1;
	} else {
	    len = s->length()*2 - (uint)ioIndex;
	}
    }
    memcpy( p, ((const char*)(s->unicode()))+ioIndex, len );
    ioIndex += len;
    return len;
}

Q_LONG QStringBuffer::writeBlock( const char *p, Q_ULONG len )
{
#if defined(QT_CHECK_NULL)
    if ( p == 0 && len != 0 )
	qWarning( "QStringBuffer::writeBlock: Null pointer error" );
#endif
#if defined(QT_CHECK_STATE)
    if ( !isOpen() ) {
	qWarning( "QStringBuffer::writeBlock: Buffer not open" );
	return -1;
    }
    if ( !isWritable() ) {
	qWarning( "QStringBuffer::writeBlock: Write operation not permitted" );
	return -1;
    }
    if ( ioIndex&1 ) {
	qWarning( "QStringBuffer::writeBlock: non-even index - non Unicode" );
	return -1;
    }
    if ( len&1 ) {
	qWarning( "QStringBuffer::writeBlock: non-even length - non Unicode" );
	return -1;
    }
#endif
    s->replace(ioIndex/2, len/2, (QChar*)p, len/2);
    ioIndex += len;
    return len;
}

int QStringBuffer::getch()
{
#if defined(QT_CHECK_STATE)
    if ( !isOpen() ) {
	qWarning( "QStringBuffer::getch: Buffer not open" );
	return -1;
    }
    if ( !isReadable() ) {
	qWarning( "QStringBuffer::getch: Read operation not permitted" );
	return -1;
    }
#endif
    if ( (uint)ioIndex >= s->length()*2 ) {           // overflow
	setStatus( IO_ReadError );
	return -1;
    }
    return (int)((const uchar *)s->unicode())[ioIndex++];
}

int QStringBuffer::putch( int ch )
{
    char c = ch;
    if ( writeBlock(&c,1) < 0 )
	return -1;
    else
	return ch;
}

int QStringBuffer::ungetch( int ch )
{
#if defined(QT_CHECK_STATE)
    if ( !isOpen() ) {
	qWarning( "QStringBuffer::ungetch: Buffer not open" );
	return -1;
    }
    if ( !isReadable() ) {
	qWarning( "QStringBuffer::ungetch: Read operation not permitted" );
	return -1;
    }
#endif
    if ( ch != -1 ) { // something to do with eof
	if ( ioIndex )
	    ioIndex--;
	else
	    ch = -1;
    }
    return ch;
}


/*!
    Constructs a text stream that operates on the Unicode QString, \a
    str, through an internal device. The \a filemode argument is
    passed to the device's open() function; see \l{QIODevice::mode()}.

    If you set an encoding or codec with setEncoding() or setCodec(),
    this setting is ignored for text streams that operate on QString.

    Example:
    \code
    QString str;
    QTextStream ts( &str, IO_WriteOnly );
    ts << "pi = " << 3.14; // str == "pi = 3.14"
    \endcode

    Writing data to the text stream will modify the contents of the
    string. The string will be expanded when data is written beyond
    the end of the string. Note that the string will not be truncated:
    \code
    QString str = "pi = 3.14";
    QTextStream ts( &str, IO_WriteOnly );
    ts <<  "2+2 = " << 2+2; // str == "2+2 = 414"
    \endcode

    Note that because QString is Unicode, you should not use
    readRawBytes() or writeRawBytes() on such a stream.
*/

QTextStream::QTextStream( QString* str, int filemode )
{
    // TODO: optimize for this case as it becomes more common
    //        (see QStringBuffer above)
    init();
    dev = new QStringBuffer( str );
    ((QStringBuffer *)dev)->open( filemode );
    owndev = TRUE;
    setEncoding(RawUnicode);
    reset();
    d->sourceType = QTextStreamPrivate::String;
}

/*! \obsolete

  This constructor is equivalent to the constructor taking a QString*
  parameter.
*/

QTextStream::QTextStream( QString& str, int filemode )
{
    init();
    dev = new QStringBuffer( &str );
    ((QStringBuffer *)dev)->open( filemode );
    owndev = TRUE;
    setEncoding(RawUnicode);
    reset();
    d->sourceType = QTextStreamPrivate::String;
}

/*!
    Constructs a text stream that operates on the byte array, \a a,
    through an internal QBuffer device. The \a mode argument is passed
    to the device's open() function; see \l{QIODevice::mode()}.

    Example:
    \code
    QByteArray array;
    QTextStream ts( array, IO_WriteOnly );
    ts << "pi = " << 3.14 << '\0'; // array == "pi = 3.14"
    \endcode

    Writing data to the text stream will modify the contents of the
    array. The array will be expanded when data is written beyond the
    end of the string.

    Same example, using a QBuffer:
    \code
    QByteArray array;
    QBuffer buf( array );
    buf.open( IO_WriteOnly );
    QTextStream ts( &buf );
    ts << "pi = " << 3.14 << '\0'; // array == "pi = 3.14"
    buf.close();
    \endcode
*/

QTextStream::QTextStream( QByteArray a, int mode )
{
    init();
    dev = new QBuffer( a );
    ((QBuffer *)dev)->open( mode );
    owndev = TRUE;
    setEncoding( Latin1 ); //### Locale???
    reset();
    d->sourceType = QTextStreamPrivate::ByteArray;
}

/*!
    Constructs a text stream that operates on an existing file handle
    \a fh through an internal QFile device. The \a mode argument is
    passed to the device's open() function; see \l{QIODevice::mode()}.

    Note that if you create a QTextStream \c cout or another name that
    is also used for another variable of a different type, some
    linkers may confuse the two variables, which will often cause
    crashes.
*/

QTextStream::QTextStream( FILE *fh, int mode )
{
    init();
    setEncoding( Locale ); //###
    dev = new QFile;
    ((QFile *)dev)->open( mode, fh );
    owndev = TRUE;
    reset();
    d->sourceType = QTextStreamPrivate::File;
}

/*!
    Destroys the text stream.

    The destructor does not affect the current IO device.
*/

QTextStream::~QTextStream()
{
    if ( owndev )
	delete dev;
    delete d;
}

/*!
    Positions the read pointer at the first non-whitespace character.
*/
void QTextStream::skipWhiteSpace()
{
    ts_ungetc( eat_ws() );
}


/*!
    Tries to read \a len characters from the stream and stores them in
    \a buf. Returns the number of characters really read.

    \warning There will no QEOF appended if the read reaches the end
    of the file. EOF is reached when the return value does not equal
    \a len.
*/
uint QTextStream::ts_getbuf( QChar* buf, uint len )
{
    if ( len < 1 )