00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
00012
00013
00014
00015
00016
00017
00018
00019 #ifndef klimitediodevice_h
00020 #define klimitediodevice_h
00021
00022 #include <kdebug.h>
00023 #include <tqiodevice.h>
00031 class TDEIO_EXPORT KLimitedIODevice : public TQIODevice
00032 {
00033 public:
00041 KLimitedIODevice( TQIODevice *dev, int start, int length )
00042 : m_dev( dev ), m_start( start ), m_length( length )
00043 {
00044
00045 setType( IO_Direct );
00046 open( IO_ReadOnly );
00047 }
00048 virtual ~KLimitedIODevice() {}
00049
00050 virtual bool open( TQ_OpenMode m ) {
00051
00052 if ( m & IO_ReadOnly ) {
00053
00054
00055
00056
00057
00058
00059 m_dev->at( m_start );
00060 }
00061 else
00062 kdWarning(7005) << "KLimitedIODevice::open only supports IO_ReadOnly!" << endl;
00063 setState( IO_Open );
00064 setMode( m );
00065 return true;
00066 }
00067 virtual void close() {}
00068 virtual void flush() {}
00069
00070 #ifdef USE_QT4
00071 virtual qint64 size() const { return m_length; }
00072 #else // USE_QT4
00073 virtual Offset size() const { return m_length; }
00074 #endif // USE_QT4
00075
00076 virtual TQT_TQIO_LONG tqreadBlock ( char * data, TQT_TQIO_ULONG maxlen )
00077 {
00078 maxlen = TQMIN( maxlen, m_length - at() );
00079 return m_dev->readBlock( data, maxlen );
00080 }
00081 virtual TQT_TQIO_LONG tqwriteBlock ( const char *, TQT_TQIO_ULONG ) { return -1; }
00082 virtual int putch( int ) { return -1; }
00083
00084 virtual int getch() {
00085 char c[2];
00086 if ( tqreadBlock(c, 1) == -1)
00087 return -1;
00088 else
00089 return c[0];
00090 }
00091 virtual int ungetch( int c ) { return m_dev->ungetch(c); }
00092 virtual Offset at() const { return m_dev->at() - m_start; }
00093 virtual bool at( Offset pos ) {
00094 Q_ASSERT( pos <= m_length );
00095 pos = TQMIN( pos, m_length );
00096 return m_dev->at( m_start + pos );
00097 }
00098 virtual bool atEnd() const { return m_dev->atEnd() || m_dev->at() >= m_start + m_length; }
00099 private:
00100 TQIODevice* m_dev;
00101 TQ_ULONG m_start;
00102 TQ_ULONG m_length;
00103 };
00104
00105 #endif