qiodevice.h

/****************************************************************************
** $Id: qiodevice.h,v 2.6.2.2 1998/08/21 19:13:24 hanord Exp $
**
** Definition of QIODevice class
**
** Created : 940913
**
** Copyright (C) 1992-1998 Troll Tech AS.  All rights reserved.
**
** This file is part of Qt Free Edition, version 1.42.
**
** See the file LICENSE included in the distribution for the usage
** and distribution terms, or http://www.troll.no/free-license.html.
**
** IMPORTANT NOTE: You may NOT copy this file or any part of it into
** your own programs or libraries.
**
** Please see http://www.troll.no/pricing.html for information about 
** Qt Professional Edition, which is this same library but with a
** license which allows creation of commercial/proprietary software.
**
*****************************************************************************/

#ifndef QIODEVICE_H
#define QIODEVICE_H

#ifndef QT_H
#include "qglobal.h"
#endif // QT_H


// IO device access types

#define IO_Direct               0x0100          // direct access device
#define IO_Sequential           0x0200          // sequential access device
#define IO_Combined             0x0300          // combined direct/sequential
#define IO_TypeMask             0x0f00

// IO handling modes

#define IO_Raw                  0x0040          // raw access (not buffered)
#define IO_Async                0x0080          // asynchronous mode

// IO device open modes

#define IO_ReadOnly             0x0001          // readable device
#define IO_WriteOnly            0x0002          // writeable device
#define IO_ReadWrite            0x0003          // read+write device
#define IO_Append               0x0004          // append
#define IO_Truncate             0x0008          // truncate device
#define IO_Translate            0x0010          // translate CR+LF
#define IO_ModeMask             0x00ff

// IO device state

#define IO_Open                 0x1000          // device is open
#define IO_StateMask            0xf000


// IO device status

#define IO_Ok                   0
#define IO_ReadError            1               // read error
#define IO_WriteError           2               // write error
#define IO_FatalError           3               // fatal unrecoverable error
#define IO_ResourceError        4               // resource limitation
#define IO_OpenError            5               // cannot open device
#define IO_ConnectError         5               // cannot connect to device
#define IO_AbortError           6               // abort error
#define IO_TimeOutError         7               // time out

#undef  TB
#define TB(x) ((ioMode & (x)) == (x))


class Q_EXPORT QIODevice                                        // IO device class
{
public:
    QIODevice();
    virtual ~QIODevice();

    int          flags()  const { return ioMode; }
    int          mode()   const { return ioMode & IO_ModeMask; }
    int          state()  const { return ioMode & IO_StateMask; }

    bool         isDirectAccess()     const { return TB(IO_Direct); }
    bool         isSequentialAccess() const { return TB(IO_Sequential); }
    bool         isCombinedAccess()   const { return TB(IO_Combined); }
    bool         isBuffered()         const { return !TB(IO_Raw); }
    bool         isRaw()              const { return TB(IO_Raw); }
    bool         isSynchronous()      const { return !TB(IO_Async); }
    bool         isAsynchronous()     const { return TB(IO_Async); }
    bool         isTranslated()       const { return TB(IO_Translate); }
    bool         isReadable()         const { return TB(IO_ReadOnly); }
    bool         isWritable()         const { return TB(IO_WriteOnly); }
    bool         isReadWrite()        const { return TB(IO_ReadWrite); }
    bool         isInactive()         const { return state() == 0; }
    bool         isOpen()             const { return state() == IO_Open; }

    int          status() const { return ioSt; }
    void         resetStatus()  { ioSt = IO_Ok; }

    virtual bool open( int mode ) = 0;
    virtual void close() = 0;
    virtual void flush() = 0;

    virtual uint size()   const = 0;
    virtual int  at()     const;
    virtual bool at( int );
    virtual bool atEnd()  const;
    bool         reset() { return at(0); }

    virtual int  readBlock( char *data, uint len ) = 0;
    virtual int  writeBlock( const char *data, uint len ) = 0;
    virtual int  readLine( char *data, uint maxlen );

    virtual int  getch() = 0;
    virtual int  putch( int ) = 0;
    virtual int  ungetch( int ) = 0;

protected:
    void         setFlags( int f ) { ioMode = f; }
    void         setType( int );
    void         setMode( int );
    void         setState( int );
    void         setStatus( int );
    int          index;

private:
    int          ioMode;
    int          ioSt;

private:        // Disabled copy constructor and operator=
#if defined(Q_DISABLE_COPY)
    QIODevice( const QIODevice & );
    QIODevice &operator=( const QIODevice & );
#endif
};


#undef  TB


#endif // QIODEVICE_H