<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/src/tools/qiodevice.cpp:40 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>TQIODevice Class</title> <style type="text/css"><!-- fn { margin-left: 1cm; text-indent: -1cm; } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } body { background: #ffffff; color: black; } --></style> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr bgcolor="#E5E5E5"> <td valign=center> <a href="index.html"> <font color="#004faf">Home</font></a> | <a href="classes.html"> <font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"> <font color="#004faf">Main Classes</font></a> | <a href="annotated.html"> <font color="#004faf">Annotated</font></a> | <a href="groups.html"> <font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"> <font color="#004faf">Functions</font></a> </td> <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>TQIODevice Class Reference</h1> <p>The TQIODevice class is the base class of I/O devices. <a href="#details">More...</a> <p>All the functions in this class are <a href="threads.html#reentrant">reentrant</a> when TQt is built with thread support.</p> <p><tt>#include <<a href="qiodevice-h.html">ntqiodevice.h</a>></tt> <p>Inherited by <a href="ntqbuffer.html">TQBuffer</a>, <a href="ntqfile.html">TQFile</a>, <a href="ntqsocket.html">TQSocket</a>, and <a href="ntqsocketdevice.html">TQSocketDevice</a>. <p><a href="qiodevice-members.html">List of all member functions.</a> <h2>Public Members</h2> <ul> <li class=fn>typedef TQ_ULONG <a href="#Offset"><b>Offset</b></a></li> <li class=fn><a href="#TQIODevice"><b>TQIODevice</b></a> ()</li> <li class=fn>virtual <a href="#~TQIODevice"><b>~TQIODevice</b></a> ()</li> <li class=fn>int <a href="#flags"><b>flags</b></a> () const</li> <li class=fn>int <a href="#mode"><b>mode</b></a> () const</li> <li class=fn>int <a href="#state"><b>state</b></a> () const</li> <li class=fn>bool <a href="#isDirectAccess"><b>isDirectAccess</b></a> () const</li> <li class=fn>bool <a href="#isSequentialAccess"><b>isSequentialAccess</b></a> () const</li> <li class=fn>bool <a href="#isCombinedAccess"><b>isCombinedAccess</b></a> () const</li> <li class=fn>bool <a href="#isBuffered"><b>isBuffered</b></a> () const</li> <li class=fn>bool <a href="#isRaw"><b>isRaw</b></a> () const</li> <li class=fn>bool <a href="#isSynchronous"><b>isSynchronous</b></a> () const</li> <li class=fn>bool <a href="#isAsynchronous"><b>isAsynchronous</b></a> () const</li> <li class=fn>bool <a href="#isTranslated"><b>isTranslated</b></a> () const</li> <li class=fn>bool <a href="#isReadable"><b>isReadable</b></a> () const</li> <li class=fn>bool <a href="#isWritable"><b>isWritable</b></a> () const</li> <li class=fn>bool <a href="#isReadWrite"><b>isReadWrite</b></a> () const</li> <li class=fn>bool <a href="#isInactive"><b>isInactive</b></a> () const</li> <li class=fn>bool <a href="#isOpen"><b>isOpen</b></a> () const</li> <li class=fn>int <a href="#status"><b>status</b></a> () const</li> <li class=fn>void <a href="#resetStatus"><b>resetStatus</b></a> ()</li> <li class=fn>virtual bool <a href="#open"><b>open</b></a> ( int mode ) = 0</li> <li class=fn>virtual void <a href="#close"><b>close</b></a> () = 0</li> <li class=fn>virtual void <a href="#flush"><b>flush</b></a> () = 0</li> <li class=fn>virtual Offset <a href="#size"><b>size</b></a> () const = 0</li> <li class=fn>virtual Offset <a href="#at"><b>at</b></a> () const</li> <li class=fn>virtual bool <a href="#at-2"><b>at</b></a> ( Offset pos )</li> <li class=fn>virtual bool <a href="#atEnd"><b>atEnd</b></a> () const</li> <li class=fn>bool <a href="#reset"><b>reset</b></a> ()</li> <li class=fn>virtual TQ_LONG <a href="#readBlock"><b>readBlock</b></a> ( char * data, TQ_ULONG maxlen ) = 0</li> <li class=fn>virtual TQ_LONG <a href="#writeBlock"><b>writeBlock</b></a> ( const char * data, TQ_ULONG len ) = 0</li> <li class=fn>virtual TQ_LONG <a href="#readLine"><b>readLine</b></a> ( char * data, TQ_ULONG maxlen )</li> <li class=fn>TQ_LONG <a href="#writeBlock-2"><b>writeBlock</b></a> ( const TQByteArray & data )</li> <li class=fn>virtual TQByteArray <a href="#readAll"><b>readAll</b></a> ()</li> <li class=fn>virtual int <a href="#getch"><b>getch</b></a> () = 0</li> <li class=fn>virtual int <a href="#putch"><b>putch</b></a> ( int ch ) = 0</li> <li class=fn>virtual int <a href="#ungetch"><b>ungetch</b></a> ( int ch ) = 0</li> </ul> <h2>Protected Members</h2> <ul> <li class=fn>void <a href="#setFlags"><b>setFlags</b></a> ( int flags )</li> <li class=fn>void <a href="#setType"><b>setType</b></a> ( int type )</li> <li class=fn>void <a href="#setMode"><b>setMode</b></a> ( int mode )</li> <li class=fn>void <a href="#setState"><b>setState</b></a> ( int state )</li> <li class=fn>void <a href="#setStatus"><b>setStatus</b></a> ( int s )</li> </ul> <hr><a name="details"></a><h2>Detailed Description</h2> <p> The TQIODevice class is the base class of I/O devices. <p> <p> An I/O device represents a medium that one can read bytes from and/or write bytes to. The TQIODevice class is the abstract superclass of all such devices; classes such as <a href="ntqfile.html">TQFile</a>, <a href="ntqbuffer.html">TQBuffer</a> and <a href="ntqsocket.html">TQSocket</a> inherit TQIODevice and implement virtual functions such as write() appropriately. <p> Although applications sometimes use TQIODevice directly, it is usually better to use <a href="ntqtextstream.html">TQTextStream</a> and <a href="ntqdatastream.html">TQDataStream</a>, which provide stream operations on any TQIODevice subclass. TQTextStream provides text-oriented stream functionality (for human-readable ASCII files, for example), whereas TQDataStream deals with binary data in a totally platform-independent manner. <p> The public member functions in TQIODevice roughly fall into two groups: the action functions and the state access functions. The most important action functions are: <p> <ul> <p> <li> <a href="#open">open</a>() opens a device for reading and/or writing, depending on the mode argument. <p> <li> <a href="#close">close</a>() closes the device and tidies up (e.g. flushes buffered data) <p> <li> <a href="#readBlock">readBlock</a>() reads a block of data from the device. <p> <li> <a href="#writeBlock">writeBlock</a>() writes a block of data to the device. <p> <li> <a href="#readLine">readLine</a>() reads a line (of text, usually) from the device. <p> <li> <a href="#flush">flush</a>() ensures that all buffered data are written to the real device. <p> </ul> <p> There are also some other, less used, action functions: <p> <ul> <p> <li> <a href="#getch">getch</a>() reads a single character. <p> <li> <a href="#ungetch">ungetch</a>() forgets the last call to getch(), if possible. <p> <li> <a href="#putch">putch</a>() writes a single character. <p> <li> <a href="#size">size</a>() returns the size of the device, if there is one. <p> <li> <a href="#at">at</a>() returns the current read/write pointer's position, if there is one for this device, or it moves the pointer if given an offset. <p> <li> <a href="#atEnd">atEnd</a>() indicates whether there is more to read, if this is meaningful for this device. <p> <li> <a href="#reset">reset</a>() moves the read/write pointer to the start of the device, if that is possible for this device. <p> </ul> <p> The state access are all "get" functions. The TQIODevice subclass calls <a href="#setState">setState</a>() to update the state, and simple access functions tell the user of the device what the device's state is. Here are the settings, and their associated access functions: <p> <ul> <p> <li> Access type. Some devices are direct access (it is possible to read/write anywhere), whereas others are sequential. TQIODevice provides the access functions (<a href="#isDirectAccess">isDirectAccess</a>(), <a href="#isSequentialAccess">isSequentialAccess</a>(), and <a href="#isCombinedAccess">isCombinedAccess</a>()) to tell users what a given I/O device supports. <p> <li> Buffering. Some devices are accessed in raw mode, whereas others are buffered. Buffering usually provides greater efficiency, particularly for small read/write operations. <a href="#isBuffered">isBuffered</a>() tells the user whether a given device is buffered. (This can often be set by the application in the call to <a href="#open">open</a>().) <p> <li> Synchronicity. Synchronous devices work immediately (for example, files). When you read from a file, the file delivers its data straight away. Other kinds of device, such as a socket connected to a HTTP server, may not deliver the data until seconds after you ask to read it. <a href="#isSynchronous">isSynchronous</a>() and <a href="#isAsynchronous">isAsynchronous</a>() tell the user how this device operates. <p> <li> CR/LF translation. For simplicity, applications often like to see just a single CR/LF style, and TQIODevice subclasses can provide this. <a href="#isTranslated">isTranslated</a>() returns TRUE if this object translates CR/LF to just LF. (This can often be set by the application in the call to open().) <p> <li> Permissions. Some files cannot be written. For example, <a href="#isReadable">isReadable</a>(), <a href="#isWritable">isWritable</a>() and <a href="#isReadWrite">isReadWrite</a>() tell the application whether it can read from and write to a given device. (This can often be set by the application in the call to <a href="#open">open</a>().) <p> <li> Finally, <a href="#isOpen">isOpen</a>() returns TRUE if the device is open, i.e. after an open() call. <p> </ul> <p> TQIODevice provides numerous pure virtual functions that you need to implement when subclassing it. Here is a skeleton subclass with all the members you are sure to need and some that you will probably need: <p> <pre> class MyDevice : public TQIODevice { public: MyDevice(); ~MyDevice(); bool open( int mode ); void close(); void flush(); uint size() const; int at() const; // non-pure virtual bool at( int ); // non-pure virtual bool atEnd() const; // non-pure virtual int readBlock( char *data, uint maxlen ); int writeBlock( const char *data, uint len ); int readLine( char *data, uint maxlen ); int getch(); int putch( int ); int ungetch( int ); }; </pre> <p> The three non-pure virtual functions need not be reimplemented for sequential devices. <p> <p>See also <a href="ntqdatastream.html">TQDataStream</a>, <a href="ntqtextstream.html">TQTextStream</a>, and <a href="io.html">Input/Output and Networking</a>. <hr><h2>Member Type Documentation</h2> <h3 class=fn><a name="Offset"></a>TQIODevice::Offset</h3> <p> The offset within the device. <hr><h2>Member Function Documentation</h2> <h3 class=fn><a name="TQIODevice"></a>TQIODevice::TQIODevice () </h3> Constructs an I/O device. <h3 class=fn><a name="~TQIODevice"></a>TQIODevice::~TQIODevice ()<tt> [virtual]</tt> </h3> Destroys the I/O device. <h3 class=fn><a href="ntqiodevice.html#Offset">Offset</a> <a name="at"></a>TQIODevice::at () const<tt> [virtual]</tt> </h3> Virtual function that returns the current I/O device position. <p> This is the position of the data read/write head of the I/O device. <p> <p>See also <a href="#size">size</a>(). <p>Example: <a href="distributor-example.html#x2666">distributor/distributor.ui.h</a>. <p>Reimplemented in <a href="ntqsocket.html#at">TQSocket</a>. <h3 class=fn>bool <a name="at-2"></a>TQIODevice::at ( <a href="ntqiodevice.html#Offset">Offset</a> pos )<tt> [virtual]</tt> </h3> Virtual function that sets the I/O device position to <em>pos</em>. Returns TRUE if the position was successfully set, i.e. <em>pos</em> is within range and the seek was successful; otherwise returns FALSE. <p> <p>See also <a href="#size">size</a>(). <p>Reimplemented in <a href="ntqsocket.html#at-2">TQSocket</a>. <h3 class=fn>bool <a name="atEnd"></a>TQIODevice::atEnd () const<tt> [virtual]</tt> </h3> Virtual function that returns TRUE if the I/O device position is at the end of the input; otherwise returns FALSE. <p>Reimplemented in <a href="ntqfile.html#atEnd">TQFile</a> and <a href="ntqsocket.html#atEnd">TQSocket</a>. <h3 class=fn>void <a name="close"></a>TQIODevice::close ()<tt> [pure virtual]</tt> </h3> <p> Closes the I/O device. <p> This virtual function must be reimplemented by all subclasses. <p> <p>See also <a href="#open">open</a>(). <p>Example: <a href="grapher-nsplugin-example.html#x2742">grapher/grapher.cpp</a>. <p>Reimplemented in <a href="ntqfile.html#close">TQFile</a> and <a href="ntqsocket.html#close">TQSocket</a>. <h3 class=fn>int <a name="flags"></a>TQIODevice::flags () const </h3> <p> Returns the current I/O device flags setting. <p> Flags consists of mode flags and state flags. <p> <p>See also <a href="#mode">mode</a>() and <a href="#state">state</a>(). <h3 class=fn>void <a name="flush"></a>TQIODevice::flush ()<tt> [pure virtual]</tt> </h3> <p> Flushes an open I/O device. <p> This virtual function must be reimplemented by all subclasses. <p>Reimplemented in <a href="ntqfile.html#flush">TQFile</a> and <a href="ntqsocket.html#flush">TQSocket</a>. <h3 class=fn>int <a name="getch"></a>TQIODevice::getch ()<tt> [pure virtual]</tt> </h3> <p> Reads a single byte/character from the I/O device. <p> Returns the byte/character read, or -1 if the end of the I/O device has been reached. <p> This virtual function must be reimplemented by all subclasses. <p> <p>See also <a href="#putch">putch</a>() and <a href="#ungetch">ungetch</a>(). <p>Reimplemented in <a href="ntqfile.html#getch">TQFile</a> and <a href="ntqsocket.html#getch">TQSocket</a>. <h3 class=fn>bool <a name="isAsynchronous"></a>TQIODevice::isAsynchronous () const </h3> <p> Returns TRUE if the device is an asynchronous device; otherwise returns FALSE, i.e. if the device is a synchronous device. <p> This mode is currently not in use. <p> <p>See also <a href="#isSynchronous">isSynchronous</a>(). <h3 class=fn>bool <a name="isBuffered"></a>TQIODevice::isBuffered () const </h3> <p> Returns TRUE if the I/O device is a buffered device; otherwise returns FALSE, i.e. the device is a raw device. <p> <p>See also <a href="#isRaw">isRaw</a>(). <h3 class=fn>bool <a name="isCombinedAccess"></a>TQIODevice::isCombinedAccess () const </h3> <p> Returns TRUE if the I/O device is a combined access (both direct and sequential) device; otherwise returns FALSE. <p> This access method is currently not in use. <h3 class=fn>bool <a name="isDirectAccess"></a>TQIODevice::isDirectAccess () const </h3> <p> Returns TRUE if the I/O device is a direct access device; otherwise returns FALSE, i.e. if the device is a sequential access device. <p> <p>See also <a href="#isSequentialAccess">isSequentialAccess</a>(). <h3 class=fn>bool <a name="isInactive"></a>TQIODevice::isInactive () const </h3> <p> Returns TRUE if the I/O device state is 0, i.e. the device is not open; otherwise returns FALSE. <p> <p>See also <a href="#isOpen">isOpen</a>(). <h3 class=fn>bool <a name="isOpen"></a>TQIODevice::isOpen () const </h3> <p> Returns TRUE if the I/O device has been opened; otherwise returns FALSE. <p> <p>See also <a href="#isInactive">isInactive</a>(). <p>Example: <a href="networkprotocol-example.html#x670">network/networkprotocol/nntp.cpp</a>. <h3 class=fn>bool <a name="isRaw"></a>TQIODevice::isRaw () const </h3> <p> Returns TRUE if the device is a raw device; otherwise returns FALSE, i.e. if the device is a buffered device. <p> <p>See also <a href="#isBuffered">isBuffered</a>(). <h3 class=fn>bool <a name="isReadWrite"></a>TQIODevice::isReadWrite () const </h3> <p> Returns TRUE if the I/O device was opened using <a href="ntqfile.html#open">IO_ReadWrite</a> mode; otherwise returns FALSE. <p> <p>See also <a href="#isReadable">isReadable</a>() and <a href="#isWritable">isWritable</a>(). <h3 class=fn>bool <a name="isReadable"></a>TQIODevice::isReadable () const </h3> <p> Returns TRUE if the I/O device was opened using <a href="ntqfile.html#open">IO_ReadOnly</a> or <a href="ntqfile.html#open">IO_ReadWrite</a> mode; otherwise returns FALSE. <p> <p>See also <a href="#isWritable">isWritable</a>() and <a href="#isReadWrite">isReadWrite</a>(). <h3 class=fn>bool <a name="isSequentialAccess"></a>TQIODevice::isSequentialAccess () const </h3> <p> Returns TRUE if the device is a sequential access device; otherwise returns FALSE, i.e. if the device is a direct access device. <p> Operations involving <a href="#size">size</a>() and <a href="#at">at</a>(int) are not valid on sequential devices. <p> <p>See also <a href="#isDirectAccess">isDirectAccess</a>(). <h3 class=fn>bool <a name="isSynchronous"></a>TQIODevice::isSynchronous () const </h3> <p> Returns TRUE if the I/O device is a synchronous device; otherwise returns FALSE, i.e. the device is an asynchronous device. <p> <p>See also <a href="#isAsynchronous">isAsynchronous</a>(). <h3 class=fn>bool <a name="isTranslated"></a>TQIODevice::isTranslated () const </h3> <p> Returns TRUE if the I/O device translates carriage-return and linefeed characters; otherwise returns FALSE. <p> A <a href="ntqfile.html">TQFile</a> is translated if it is opened with the <a href="ntqfile.html#open">IO_Translate</a> mode flag. <h3 class=fn>bool <a name="isWritable"></a>TQIODevice::isWritable () const </h3> <p> Returns TRUE if the I/O device was opened using <a href="ntqfile.html#open">IO_WriteOnly</a> or <a href="ntqfile.html#open">IO_ReadWrite</a> mode; otherwise returns FALSE. <p> <p>See also <a href="#isReadable">isReadable</a>() and <a href="#isReadWrite">isReadWrite</a>(). <h3 class=fn>int <a name="mode"></a>TQIODevice::mode () const </h3> <p> Returns bits OR'ed together that specify the current operation mode. <p> These are the flags that were given to the <a href="#open">open</a>() function. <p> The flags are <a href="ntqfile.html#open">IO_ReadOnly</a>, <a href="ntqfile.html#open">IO_WriteOnly</a>, <a href="ntqfile.html#open">IO_ReadWrite</a>, <a href="ntqfile.html#open">IO_Append</a>, <a href="ntqfile.html#open">IO_Truncate</a> and <a href="ntqfile.html#open">IO_Translate</a>. <h3 class=fn>bool <a name="open"></a>TQIODevice::open ( int mode )<tt> [pure virtual]</tt> </h3> <p> Opens the I/O device using the specified <em>mode</em>. Returns TRUE if the device was successfully opened; otherwise returns FALSE. <p> The mode parameter <em>mode</em> must be an OR'ed combination of the following flags. <center><table cellpadding="4" cellspacing="2" border="0"> <tr bgcolor="#a2c511"> <th valign="top">Mode flags <th valign="top">Meaning <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqfile.html#open">IO_Raw</a> <td valign="top">specifies raw (unbuffered) file access. <tr bgcolor="#d0d0d0"> <td valign="top"><a href="ntqfile.html#open">IO_ReadOnly</a> <td valign="top">opens a file in read-only mode. <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqfile.html#open">IO_WriteOnly</a> <td valign="top">opens a file in write-only mode. <tr bgcolor="#d0d0d0"> <td valign="top"><a href="ntqfile.html#open">IO_ReadWrite</a> <td valign="top">opens a file in read/write mode. <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqfile.html#open">IO_Append</a> <td valign="top">sets the file index to the end of the file. <tr bgcolor="#d0d0d0"> <td valign="top"><a href="ntqfile.html#open">IO_Truncate</a> <td valign="top">truncates the file. <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqfile.html#open">IO_Translate</a> <td valign="top">enables carriage returns and linefeed translation for text files under MS-DOS, Windows and Macintosh. On Unix systems this flag has no effect. Use with caution as it will also transform every linefeed written to the file into a CRLF pair. This is likely to corrupt your file if you write write binary data. Cannot be combined with <a href="ntqfile.html#open">IO_Raw</a>. </table></center> <p> This virtual function must be reimplemented by all subclasses. <p> <p>See also <a href="#close">close</a>(). <p>Example: <a href="grapher-nsplugin-example.html#x2743">grapher/grapher.cpp</a>. <p>Reimplemented in <a href="ntqfile.html#open">TQFile</a> and <a href="ntqsocket.html#open">TQSocket</a>. <h3 class=fn>int <a name="putch"></a>TQIODevice::putch ( int ch )<tt> [pure virtual]</tt> </h3> <p> Writes the character <em>ch</em> to the I/O device. <p> Returns <em>ch</em>, or -1 if an error occurred. <p> This virtual function must be reimplemented by all subclasses. <p> <p>See also <a href="#getch">getch</a>() and <a href="#ungetch">ungetch</a>(). <p>Example: <a href="grapher-nsplugin-example.html#x2744">grapher/grapher.cpp</a>. <p>Reimplemented in <a href="ntqfile.html#putch">TQFile</a> and <a href="ntqsocket.html#putch">TQSocket</a>. <h3 class=fn><a href="qbytearray.html">TQByteArray</a> <a name="readAll"></a>TQIODevice::readAll ()<tt> [virtual]</tt> </h3> This convenience function returns all of the remaining data in the device. <h3 class=fn>TQ_LONG <a name="readBlock"></a>TQIODevice::readBlock ( char * data, TQ_ULONG maxlen )<tt> [pure virtual]</tt> </h3> <p> Reads at most <em>maxlen</em> bytes from the I/O device into <em>data</em> and returns the number of bytes actually read. <p> This function should return -1 if a fatal error occurs and should return 0 if there are no bytes to read. <p> The device must be opened for reading, and <em>data</em> must not be 0. <p> This virtual function must be reimplemented by all subclasses. <p> <p>See also <a href="#writeBlock">writeBlock</a>(), <a href="#isOpen">isOpen</a>(), and <a href="#isReadable">isReadable</a>(). <p>Example: <a href="distributor-example.html#x2667">distributor/distributor.ui.h</a>. <p>Reimplemented in <a href="ntqsocket.html#readBlock">TQSocket</a> and <a href="ntqsocketdevice.html#readBlock">TQSocketDevice</a>. <h3 class=fn>TQ_LONG <a name="readLine"></a>TQIODevice::readLine ( char * data, TQ_ULONG maxlen )<tt> [virtual]</tt> </h3> Reads a line of text, (or up to <em>maxlen</em> bytes if a newline isn't encountered) plus a terminating '\0' into <em>data</em>. If there is a newline at the end if the line, it is not stripped. <p> Returns the number of bytes read including the terminating '\0', or -1 if an error occurred. <p> This virtual function can be reimplemented much more efficiently by the most subclasses. <p> <p>See also <a href="#readBlock">readBlock</a>() and <a href="ntqtextstream.html#readLine">TQTextStream::readLine</a>(). <p>Reimplemented in <a href="ntqfile.html#readLine">TQFile</a>. <h3 class=fn>bool <a name="reset"></a>TQIODevice::reset () </h3> <p> Sets the device index position to 0. <p> <p>See also <a href="#at">at</a>(). <h3 class=fn>void <a name="resetStatus"></a>TQIODevice::resetStatus () </h3> <p> Sets the I/O device status to <a href="ntqiodevice.html#status">IO_Ok</a>. <p> <p>See also <a href="#status">status</a>(). <h3 class=fn>void <a name="setFlags"></a>TQIODevice::setFlags ( int flags )<tt> [protected]</tt> </h3> <p> Used by subclasses to set the device flags to the <em>flags</em> specified. <h3 class=fn>void <a name="setMode"></a>TQIODevice::setMode ( int mode )<tt> [protected]</tt> </h3> <p> Used by subclasses to set the device mode to the <em>mode</em> specified. <h3 class=fn>void <a name="setState"></a>TQIODevice::setState ( int state )<tt> [protected]</tt> </h3> <p> Used by subclasses to set the device state to the <em>state</em> specified. <h3 class=fn>void <a name="setStatus"></a>TQIODevice::setStatus ( int s )<tt> [protected]</tt> </h3> Used by subclasses to set the device status (not state) to <em>s</em>. <h3 class=fn>void <a name="setType"></a>TQIODevice::setType ( int type )<tt> [protected]</tt> </h3> <p> Used by subclasses to set the device type to the <em>type</em> specified. <h3 class=fn><a href="ntqiodevice.html#Offset">Offset</a> <a name="size"></a>TQIODevice::size () const<tt> [pure virtual]</tt> </h3> <p> Virtual function that returns the size of the I/O device. <p> <p>See also <a href="#at">at</a>(). <p>Reimplemented in <a href="ntqfile.html#size">TQFile</a> and <a href="ntqsocket.html#size">TQSocket</a>. <h3 class=fn>int <a name="state"></a>TQIODevice::state () const </h3> <p> Returns bits OR'ed together that specify the current state. <p> The flags are: <tt>IO_Open</tt>. <p> Subclasses may define additional flags. <h3 class=fn>int <a name="status"></a>TQIODevice::status () const </h3> <p> Returns the I/O device status. <p> The I/O device status returns an error code. If <a href="#open">open</a>() returns FALSE or <a href="#readBlock">readBlock</a>() or <a href="#writeBlock">writeBlock</a>() return -1, this function can be called to find out the reason why the operation failed. <p> <!-- index IO_Ok --><!-- index IO_ReadError --><!-- index IO_WriteError --><!-- index IO_FatalError --><!-- index IO_OpenError --><!-- index IO_ConnectError --><!-- index IO_AbortError --><!-- index IO_TimeOutError --><!-- index IO_UnspecifiedError --> <p> The status codes are: <center><table cellpadding="4" cellspacing="2" border="0"> <tr bgcolor="#a2c511"> <th valign="top">Status code <th valign="top">Meaning <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqiodevice.html#status">IO_Ok</a> <td valign="top">The operation was successful. <tr bgcolor="#d0d0d0"> <td valign="top"><a href="ntqiodevice.html#status">IO_ReadError</a> <td valign="top">Could not read from the device. <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqiodevice.html#status">IO_WriteError</a> <td valign="top">Could not write to the device. <tr bgcolor="#d0d0d0"> <td valign="top"><a href="ntqiodevice.html#status">IO_FatalError</a> <td valign="top">A fatal unrecoverable error occurred. <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqiodevice.html#status">IO_OpenError</a> <td valign="top">Could not open the device. <tr bgcolor="#d0d0d0"> <td valign="top"><a href="ntqiodevice.html#status">IO_ConnectError</a> <td valign="top">Could not connect to the device. <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqiodevice.html#status">IO_AbortError</a> <td valign="top">The operation was unexpectedly aborted. <tr bgcolor="#d0d0d0"> <td valign="top"><a href="ntqiodevice.html#status">IO_TimeOutError</a> <td valign="top">The operation timed out. <tr bgcolor="#f0f0f0"> <td valign="top"><a href="ntqiodevice.html#status">IO_UnspecifiedError</a> <td valign="top">An unspecified error happened on close. </table></center> <p> <p>See also <a href="#resetStatus">resetStatus</a>(). <h3 class=fn>int <a name="ungetch"></a>TQIODevice::ungetch ( int ch )<tt> [pure virtual]</tt> </h3> <p> Puts the character <em>ch</em> back into the I/O device and decrements the index position if it is not zero. <p> This function is normally called to "undo" a <a href="#getch">getch</a>() operation. <p> Returns <em>ch</em>, or -1 if an error occurred. <p> This virtual function must be reimplemented by all subclasses. <p> <p>See also <a href="#getch">getch</a>() and <a href="#putch">putch</a>(). <p>Reimplemented in <a href="ntqfile.html#ungetch">TQFile</a> and <a href="ntqsocket.html#ungetch">TQSocket</a>. <h3 class=fn>TQ_LONG <a name="writeBlock"></a>TQIODevice::writeBlock ( const char * data, TQ_ULONG len )<tt> [pure virtual]</tt> </h3> <p> Writes <em>len</em> bytes from <em>data</em> to the I/O device and returns the number of bytes actually written. <p> This function should return -1 if a fatal error occurs. <p> This virtual function must be reimplemented by all subclasses. <p> <p>See also <a href="#readBlock">readBlock</a>(). <p>Example: <a href="distributor-example.html#x2668">distributor/distributor.ui.h</a>. <p>Reimplemented in <a href="ntqbuffer.html#writeBlock">TQBuffer</a>, <a href="ntqsocket.html#writeBlock">TQSocket</a>, and <a href="ntqsocketdevice.html#writeBlock">TQSocketDevice</a>. <h3 class=fn>TQ_LONG <a name="writeBlock-2"></a>TQIODevice::writeBlock ( const <a href="qbytearray.html">TQByteArray</a> & data ) </h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function. <p> This convenience function is the same as calling <a href="#writeBlock">writeBlock</a>( data.data(), data.<a href="#size">size</a>() ). <!-- eof --> <hr><p> This file is part of the <a href="index.html">TQt toolkit</a>. Copyright © 1995-2007 <a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center> <table width=100% cellspacing=0 border=0><tr> <td>Copyright © 2007 <a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> <td align=right><div align=right>TQt 3.3.8</div> </table></div></address></body> </html>