qtextstream.cpp

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/****************************************************************************
** $Id: qt/src/tools/qtextstream.cpp   2.2.3   edited 2000-10-25 $
**
** Implementation of QTextStream class
**
** Created : 940922
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the tools module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/pricing.html or email [e-mail] for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
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** not clear to you.
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**********************************************************************/

#include "qtextstream.h"

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

#if defined(_OS_WIN32_)
#include <windows.h>
#endif

// NOT REVISED
/*!
  \class QTextStream qtextstream.h

  \brief The QTextStream class provides basic functions for reading and
  writing text using a QIODevice.

  \ingroup io

  \define endl
  \define bin
  \define oct
  \define dec
  \define hex
  \define flush
  \define ws

  The text stream class has a functional interface that is very
  similar to that of the standard C++ iostream class.  The difference
  between iostream and QTextStream is that our stream operates on a
  QIODevice, which is easily subclassed, while iostream operates on
  FILE * pointers, which can not be subclassed.

  Qt provides several global functions similar to the ones in iostream:
  <ul>
  <li> \c bin sets the QTextStream to read/write binary numbers
  <li> \c oct sets the QTextStream to read/write octal numbers
  <li> \c dec sets the QTextStream to read/write decimal numbers
  <li> \c hex sets the QTextStream to read/write hexadecimal numbers
  <li> \c endl forces a line break
  <li> \c flush forces the QIODevice to flush any buffered data
  <li> \c ws eats any available white space (on input)
  <li> \c reset resets the QTextStream to its default mode (see reset()).
  </ul>

  \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, ie. the sequence "0100" will be interpreted as
  64.

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

  By default output of Unicode text (ie. 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, but otherwise the local
  8-bit encoding is used.

  \sa QDataStream
*/

/*
  \class QTSManip qtextstream.h

  \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(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.

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 ), sourceType( NotSet ) {}
    ~QTextStreamPrivate() { delete decoder; }
    QTextDecoder *decoder;		//???
#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;					// no device set
    fstrm = owndev = FALSE;
    mapper = 0;
    d = new QTextStreamPrivate;
    doUnicodeHeader = TRUE;	 //default to autodetect
    latin1 = TRUE;		 // ### should use local?
    internalOrder = QChar::networkOrdered(); //default to network order
}

/*!
  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;					// set device
    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();
    uint  size() const;
    int   at()   const;
    bool  at( int pos );
    int   readBlock( char *p, uint len );
    int writeBlock( const char *p, uint len );
    int   getch();
    int   putch( int ch );
    int   ungetch( int ch );
protected:
    QString* s;

private:        // Disabled copy constructor and operator=
    QStringBuffer( const QStringBuffer & );
    QStringBuffer &operator=( const QStringBuffer & );
};


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

QStringBuffer::~QStringBuffer()
{
}


bool QStringBuffer::open( int m )
{
    if ( !s ) {
#if defined(CHECK_STATE)
	qWarning( "QStringBuffer::open: No string" );
#endif
	return FALSE;
    }
    if ( isOpen() ) {                           // buffer already open
#if defined(CHECK_STATE)
	qWarning( "QStringBuffer::open: Buffer already open" );
#endif
	return FALSE;
    }
    setMode( m );
    if ( m & IO_Truncate ) {                    // truncate buffer
	s->truncate( 0 );
    }
    if ( m & IO_Append ) {                      // append to end of buffer
	ioIndex = s->length()*sizeof(QChar);
    } else {
	ioIndex = 0;
    }
    setState( IO_Open );
    setStatus( 0 );
    return TRUE;
}

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

void QStringBuffer::flush()
{
}

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

int  QStringBuffer::at()   const
{
    return ioIndex;
}

bool QStringBuffer::at( int pos )
{
#if defined(CHECK_STATE)
    if ( !isOpen() ) {
	qWarning( "QStringBuffer::at: Buffer is not open" );
	return FALSE;
    }
#endif
    if ( (uint)pos >= s->length()*2 ) {
#if defined(CHECK_RANGE)
	qWarning( "QStringBuffer::at: Index %d out of range", pos );
#endif
	return FALSE;
    }
    ioIndex = pos;
    return TRUE;
}


int  QStringBuffer::readBlock( char *p, uint len )
{
#if defined(CHECK_STATE)
    CHECK_PTR( p );
    if ( !isOpen() ) {                          // buffer not open
	qWarning( "QStringBuffer::readBlock: Buffer not open" );
	return -1;
    }
    if ( !isReadable() ) {                      // reading not permitted
	qWarning( "QStringBuffer::readBlock: Read operation not permitted" );
	return -1;
    }
#endif
    if ( (uint)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;
}

int QStringBuffer::writeBlock( const char *p, uint len )
{
#if defined(CHECK_NULL)
    if ( p == 0 && len != 0 )
	qWarning( "QStringBuffer::writeBlock: Null pointer error" );
#endif
#if defined(CHECK_STATE)
    if ( !isOpen() ) {                          // buffer not open
	qWarning( "QStringBuffer::writeBlock: Buffer not open" );
	return -1;
    }
    if ( !isWritable() ) {                      // writing not permitted
	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(CHECK_STATE)
    if ( !isOpen() ) {                          // buffer not open
	qWarning( "QStringBuffer::getch: Buffer not open" );
	return -1;
    }
    if ( !isReadable() ) {                      // reading not permitted
	qWarning( "QStringBuffer::getch: Read operation not permitted" );
	return -1;
    }
#endif
    if ( (uint)ioIndex >= s->length()*2 ) {           // overflow
	setStatus( IO_ReadError );
	return -1;
    }
    return *((char*)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(CHECK_STATE)
    if ( !isOpen() ) {                          // buffer not open
	qWarning( "QStringBuffer::ungetch: Buffer not open" );
	return -1;
    }
    if ( !isReadable() ) {                      // reading not permitted
	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 a Unicode QString through an
  internal device.

  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 since 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 a byte array through an
  internal QBuffer device.

  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;
}