diff options
| author | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-07-10 15:24:15 -0500 |
|---|---|---|
| committer | Timothy Pearson <kb9vqf@pearsoncomputing.net> | 2011-07-10 15:24:15 -0500 |
| commit | bd0f3345a938b35ce6a12f6150373b0955b8dd12 (patch) | |
| tree | 7a520322212d48ebcb9fbe1087e7fca28b76185c /doc/html/qdatasource.html | |
| download | qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.tar.gz qt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.zip | |
Add Qt3 development HEAD version
Diffstat (limited to 'doc/html/qdatasource.html')
| -rw-r--r-- | doc/html/qdatasource.html | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/doc/html/qdatasource.html b/doc/html/qdatasource.html new file mode 100644 index 0000000..2b22073 --- /dev/null +++ b/doc/html/qdatasource.html @@ -0,0 +1,120 @@ +<!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/kernel/qasyncio.cpp:131 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>QDataSource 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>QDataSource Class Reference<br><small>[obsolete]</small></h1> + +<p>The QDataSource class is an asynchronous producer of data. +<a href="#details">More...</a> +<p><tt>#include <<a href="qasyncio-h.html">qasyncio.h</a>></tt> +<p>Inherits <a href="qasyncio.html">QAsyncIO</a>. +<p>Inherited by <a href="qiodevicesource.html">QIODeviceSource</a>. +<p><a href="qdatasource-members.html">List of all member functions.</a> +<h2>Public Members</h2> +<ul> +<li class=fn>virtual int <a href="#readyToSend"><b>readyToSend</b></a> () = 0</li> +<li class=fn>virtual void <a href="#sendTo"><b>sendTo</b></a> ( QDataSink *, int count ) = 0</li> +<li class=fn>void <a href="#maybeReady"><b>maybeReady</b></a> ()</li> +<li class=fn>virtual bool <a href="#rewindable"><b>rewindable</b></a> () const</li> +<li class=fn>virtual void <a href="#enableRewind"><b>enableRewind</b></a> ( bool on )</li> +<li class=fn>virtual void <a href="#rewind"><b>rewind</b></a> ()</li> +</ul> +<hr><a name="details"></a><h2>Detailed Description</h2> + + +<b>This class is obsolete.</b> It is provided to keep old source working. We strongly advise against using it in new code. +<p> The QDataSource class is an asynchronous producer of data. +<p> A data source is an object which provides data from some source in an +asynchronous manner. This means that at some time not determined by +the data source, blocks of data will be taken from it for processing. +The data source is able to limit the maximum size of such blocks which +it is currently able to provide. +<p> <p>See also <a href="qasyncio.html">QAsyncIO</a>, <a href="qdatasink.html">QDataSink</a>, and <a href="qdatapump.html">QDataPump</a>. + +<hr><h2>Member Function Documentation</h2> +<h3 class=fn>void <a name="enableRewind"></a>QDataSource::enableRewind ( bool on )<tt> [virtual]</tt> +</h3> +If this function is called with <em>on</em> set to TRUE, and <a href="#rewindable">rewindable</a>() +is TRUE, then the data source must take measures to allow the <a href="#rewind">rewind</a>() +function to subsequently operate as described. If rewindable() is FALSE, +the function should call <a href="#enableRewind">QDataSource::enableRewind</a>(), which aborts with +a <a href="qapplication.html#qFatal">qFatal</a>() error. +<p> For example, a network connection may choose to use a disk cache +of input only if rewinding is enabled before the first buffer-full of +data is discarded, returning FALSE in rewindable() if that first buffer +is discarded. + +<p>Reimplemented in <a href="qiodevicesource.html#enableRewind">QIODeviceSource</a>. +<h3 class=fn>void <a name="maybeReady"></a>QDataSource::maybeReady () +</h3> +This should be called whenever <a href="#readyToSend">readyToSend</a>() might have become non-zero. +It is merely calls <a href="qasyncio.html#ready">QAsyncIO::ready</a>() if readyToSend() is non-zero. + +<h3 class=fn>int <a name="readyToSend"></a>QDataSource::readyToSend ()<tt> [pure virtual]</tt> +</h3> + +<p> The data source should return a value indicating how much data it is ready +to provide. This may be 0. If the data source knows it will never be +able to provide any more data (until after a <a href="#rewind">rewind</a>()), it may return -1. + +<p>Reimplemented in <a href="qiodevicesource.html#readyToSend">QIODeviceSource</a>. +<h3 class=fn>void <a name="rewind"></a>QDataSource::rewind ()<tt> [virtual]</tt> +</h3> +This function rewinds the data source. This may only be called if +<a href="#enableRewind">enableRewind</a>(TRUE) has been previously called. + +<p>Reimplemented in <a href="qiodevicesource.html#rewind">QIODeviceSource</a>. +<h3 class=fn>bool <a name="rewindable"></a>QDataSource::rewindable () const<tt> [virtual]</tt> +</h3> +This function should return TRUE if the data source can be rewound. +<p> The default returns FALSE. + +<p>Reimplemented in <a href="qiodevicesource.html#rewindable">QIODeviceSource</a>. +<h3 class=fn>void <a name="sendTo"></a>QDataSource::sendTo ( <a href="qdatasink.html">QDataSink</a> *, int count )<tt> [pure virtual]</tt> +</h3> + +<p> This function is called to extract data from the source, by sending +it to the given data sink. The <em>count</em> will be no more than the amount +indicated by the most recent call to <a href="#readyToSend">readyToSend</a>(). The source must +use all the provided data, and the sink will be prepared to accept at +least this much data. + +<p>Reimplemented in <a href="qiodevicesource.html#sendTo">QIODeviceSource</a>. +<!-- eof --> +<hr><p> +This file is part of the <a href="index.html">Qt 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>Qt 3.3.8</div> +</table></div></address></body> +</html> |