klimitediodevice.h
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00019 #ifndef klimitediodevice_h
00020 #define klimitediodevice_h
00021
00029 class KLimitedIODevice : public QIODevice
00030 {
00031 public:
00036 KLimitedIODevice( QIODevice *dev, int start, int length )
00037 : m_dev( dev ), m_start( start ), m_length( length )
00038 {
00039
00040 setType( IO_Direct );
00041 open( IO_ReadOnly );
00042 }
00043 virtual ~KLimitedIODevice() {}
00044
00045 virtual bool open( int m ) {
00046
00047 if ( m & IO_ReadOnly ) {
00048
00049
00050
00051
00052
00053
00054 m_dev->at( m_start );
00055 }
00056 else
00057 kdWarning(7005) << "KLimitedIODevice::open only supports IO_ReadOnly!" << endl;
00058 setState( IO_Open );
00059 setMode( m );
00060 return true;
00061 }
00062 virtual void close() {}
00063 virtual void flush() {}
00064
00065 virtual Offset size() const { return m_length; }
00066
00067 virtual Q_LONG readBlock ( char * data, Q_ULONG maxlen )
00068 {
00069 maxlen = QMIN( maxlen, m_length - at() );
00070 return m_dev->readBlock( data, maxlen );
00071 }
00072 virtual Q_LONG writeBlock ( const char *, Q_ULONG ) { return -1; }
00073 virtual int putch( int ) { return -1; }
00074
00075 virtual int getch() {
00076 char c[2];
00077 if ( readBlock(c, 1) == -1)
00078 return -1;
00079 else
00080 return c[0];
00081 }
00082 virtual int ungetch( int c ) { return m_dev->ungetch(c); }
00083 virtual Offset at() const { return m_dev->at() - m_start; }
00084 virtual bool at( Offset pos ) {
00085 Q_ASSERT( pos <= m_length );
00086 pos = QMIN( pos, m_length );
00087 return m_dev->at( m_start + pos );
00088 }
00089 virtual bool atEnd() const { return m_dev->at() >= m_start + m_length; }
00090 private:
00091 QIODevice* m_dev;
00092 Q_ULONG m_start;
00093 Q_ULONG m_length;
00094 };
00095
00096 #endif
This file is part of the documentation for kdelibs Version 3.1.5.