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#ifndef klimitediodevice_h
00020
#define klimitediodevice_h
00021
00022
#include <kdebug.h>
00023
#include <qiodevice.h>
00031 class KIO_EXPORT KLimitedIODevice :
public QIODevice
00032 {
00033
public:
00041 KLimitedIODevice(
QIODevice *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(
int 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
virtual Offset size()
const {
return m_length; }
00071
00072
virtual Q_LONG readBlock (
char * data, Q_ULONG maxlen )
00073 {
00074 maxlen = QMIN( maxlen, m_length - at() );
00075
return m_dev->readBlock( data, maxlen );
00076 }
00077
virtual Q_LONG writeBlock (
const char *, Q_ULONG ) {
return -1; }
00078
virtual int putch(
int ) {
return -1; }
00079
00080
virtual int getch() {
00081
char c[2];
00082
if ( readBlock(c, 1) == -1)
00083
return -1;
00084
else
00085
return c[0];
00086 }
00087
virtual int ungetch(
int c ) {
return m_dev->ungetch(c); }
00088
virtual Offset at()
const {
return m_dev->at() - m_start; }
00089
virtual bool at( Offset pos ) {
00090 Q_ASSERT( pos <= m_length );
00091 pos = QMIN( pos, m_length );
00092
return m_dev->at( m_start + pos );
00093 }
00094
virtual bool atEnd()
const {
return m_dev->at() >= m_start + m_length; }
00095
private:
00096
QIODevice* m_dev;
00097 Q_ULONG m_start;
00098 Q_ULONG m_length;
00099 };
00100
00101
#endif