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<li class="level1"><a href="#public-functions">Public Functions</a></li>
<li class="level1"><a href="#protected-functions">Protected Functions</a></li>
<li class="level1"><a href="#details">Detailed Description</a></li>
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<h1 class="title">QBuffer Class Reference</h1>
<!-- $$$QBuffer-brief -->
<p>The QBuffer class provides a <a href="qiodevice.html">QIODevice</a> interface for a <a href="qbytearray.html">QByteArray</a>. <a href="#details">More...</a></p>
<!-- @@@QBuffer -->
<pre class="cpp"> <span class="preprocessor">#include <QBuffer></span></pre><p><b>Inherits: </b><a href="qiodevice.html">QIODevice</a>.</p>
<p><b>Note:</b> All functions in this class are <a href="threads-reentrancy.html#reentrant">reentrant</a>.</p>
<ul>
<li><a href="qbuffer-members.html">List of all members, including inherited members</a></li>
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<a name="public-functions"></a>
<h2>Public Functions</h2>
<table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#QBuffer">QBuffer</a></b> ( QObject * <i>parent</i> = 0 )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#QBuffer-2">QBuffer</a></b> ( QByteArray * <i>byteArray</i>, QObject * <i>parent</i> = 0 )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#dtor.QBuffer">~QBuffer</a></b> ()</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> QByteArray & </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#buffer">buffer</a></b> ()</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> const QByteArray & </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#buffer-2">buffer</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> const QByteArray & </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#data">data</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#setBuffer">setBuffer</a></b> ( QByteArray * <i>byteArray</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#setData">setData</a></b> ( const QByteArray & <i>data</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#setData-2">setData</a></b> ( const char * <i>data</i>, int <i>size</i> )</td></tr>
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<a name="reimplemented-public-functions"></a>
<h2>Reimplemented Public Functions</h2>
<table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> virtual bool </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#atEnd">atEnd</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual bool </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#canReadLine">canReadLine</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual void </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#close">close</a></b> ()</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual bool </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#open">open</a></b> ( OpenMode <i>flags</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual qint64 </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#pos">pos</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual bool </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#seek">seek</a></b> ( qint64 <i>pos</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual qint64 </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#size">size</a></b> () const</td></tr>
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<ul>
<li class="fn">33 public functions inherited from <a href="qiodevice.html#public-functions">QIODevice</a></li>
<li class="fn">29 public functions inherited from <a href="qobject.html#public-functions">QObject</a></li>
</ul>
<a name="reimplemented-protected-functions"></a>
<h2>Reimplemented Protected Functions</h2>
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<tr><td class="memItemLeft rightAlign topAlign"> virtual qint64 </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#readData">readData</a></b> ( char * <i>data</i>, qint64 <i>len</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual qint64 </td><td class="memItemRight bottomAlign"><b><a href="qbuffer.html#writeData">writeData</a></b> ( const char * <i>data</i>, qint64 <i>len</i> )</td></tr>
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<ul>
<li class="fn">5 protected functions inherited from <a href="qiodevice.html#protected-functions">QIODevice</a></li>
<li class="fn">8 protected functions inherited from <a href="qobject.html#protected-functions">QObject</a></li>
</ul>
<h3>Additional Inherited Members</h3>
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<li class="fn">1 property inherited from <a href="qobject.html#properties">QObject</a></li>
<li class="fn">1 public slot inherited from <a href="qobject.html#public-slots">QObject</a></li>
<li class="fn">4 signals inherited from <a href="qiodevice.html#signals">QIODevice</a></li>
<li class="fn">1 signal inherited from <a href="qobject.html#signals">QObject</a></li>
<li class="fn">7 static public members inherited from <a href="qobject.html#static-public-members">QObject</a></li>
<li class="fn">5 protected functions inherited from <a href="qiodevice.html#protected-functions">QIODevice</a></li>
<li class="fn">8 protected functions inherited from <a href="qobject.html#protected-functions">QObject</a></li>
</ul>
<a name="details"></a>
<!-- $$$QBuffer-description -->
<div class="descr">
<h2>Detailed Description</h2>
<p>The QBuffer class provides a <a href="qiodevice.html">QIODevice</a> interface for a <a href="qbytearray.html">QByteArray</a>.</p>
<p>QBuffer allows you to access a <a href="qbytearray.html">QByteArray</a> using the <a href="qiodevice.html">QIODevice</a> interface. The <a href="qbytearray.html">QByteArray</a> is treated just as a standard random-accessed file. Example:</p>
<pre class="cpp"> <span class="type">QBuffer</span> buffer;
<span class="type">char</span> ch;
buffer<span class="operator">.</span>open(<span class="type">QBuffer</span><span class="operator">::</span>ReadWrite);
buffer<span class="operator">.</span>write(<span class="string">"Qt rocks!"</span>);
buffer<span class="operator">.</span>seek(<span class="number">0</span>);
buffer<span class="operator">.</span>getChar(<span class="operator">&</span>ch); <span class="comment">// ch == 'Q'</span>
buffer<span class="operator">.</span>getChar(<span class="operator">&</span>ch); <span class="comment">// ch == 't'</span>
buffer<span class="operator">.</span>getChar(<span class="operator">&</span>ch); <span class="comment">// ch == ' '</span>
buffer<span class="operator">.</span>getChar(<span class="operator">&</span>ch); <span class="comment">// ch == 'r'</span></pre>
<p>By default, an internal <a href="qbytearray.html">QByteArray</a> buffer is created for you when you create a QBuffer. You can access this buffer directly by calling <a href="qbuffer.html#buffer">buffer</a>(). You can also use QBuffer with an existing <a href="qbytearray.html">QByteArray</a> by calling <a href="qbuffer.html#setBuffer">setBuffer</a>(), or by passing your array to QBuffer's constructor.</p>
<p>Call <a href="qbuffer.html#open">open</a>() to open the buffer. Then call <a href="qiodevice.html#write">write</a>() or <a href="qiodevice.html#putChar">putChar</a>() to write to the buffer, and <a href="qiodevice.html#read">read</a>(), <a href="qiodevice.html#readLine">readLine</a>(), <a href="qiodevice.html#readAll">readAll</a>(), or <a href="qiodevice.html#getChar">getChar</a>() to read from it. <a href="qbuffer.html#size">size</a>() returns the current size of the buffer, and you can seek to arbitrary positions in the buffer by calling <a href="qbuffer.html#seek">seek</a>(). When you are done with accessing the buffer, call <a href="qbuffer.html#close">close</a>().</p>
<p>The following code snippet shows how to write data to a <a href="qbytearray.html">QByteArray</a> using <a href="qdatastream.html">QDataStream</a> and QBuffer:</p>
<pre class="cpp"> <span class="type"><a href="qbytearray.html">QByteArray</a></span> byteArray;
<span class="type">QBuffer</span> buffer(<span class="operator">&</span>byteArray);
buffer<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>WriteOnly);
<span class="type"><a href="qdatastream.html">QDataStream</a></span> out(<span class="operator">&</span>buffer);
out <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="qapplication.html">QApplication</a></span><span class="operator">::</span>palette();</pre>
<p>Effectively, we convert the application's <a href="qpalette.html">QPalette</a> into a byte array. Here's how to read the data from the <a href="qbytearray.html">QByteArray</a>:</p>
<pre class="cpp"> <span class="type"><a href="qpalette.html">QPalette</a></span> palette;
<span class="type">QBuffer</span> buffer(<span class="operator">&</span>byteArray);
buffer<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>ReadOnly);
<span class="type"><a href="qdatastream.html">QDataStream</a></span> in(<span class="operator">&</span>buffer);
in <span class="operator">></span><span class="operator">></span> palette;</pre>
<p><a href="qtextstream.html">QTextStream</a> and <a href="qdatastream.html">QDataStream</a> also provide convenience constructors that take a <a href="qbytearray.html">QByteArray</a> and that create a QBuffer behind the scenes.</p>
<p>QBuffer emits <a href="qiodevice.html#readyRead">readyRead</a>() when new data has arrived in the buffer. By connecting to this signal, you can use QBuffer to store temporary data before processing it. For example, you can pass the buffer to <a href="qftp.html">QFtp</a> when downloading a file from an FTP server. Whenever a new payload of data has been downloaded, <a href="qiodevice.html#readyRead">readyRead</a>() is emitted, and you can process the data that just arrived. QBuffer also emits <a href="qiodevice.html#bytesWritten">bytesWritten</a>() every time new data has been written to the buffer.</p>
</div>
<p><b>See also </b><a href="qfile.html">QFile</a>, <a href="qdatastream.html">QDataStream</a>, <a href="qtextstream.html">QTextStream</a>, and <a href="qbytearray.html">QByteArray</a>.</p>
<!-- @@@QBuffer -->
<div class="func">
<h2>Member Function Documentation</h2>
<!-- $$$QBuffer[overload1]$$$QBufferQObject* -->
<h3 class="fn"><a name="QBuffer"></a>QBuffer::<span class="name">QBuffer</span> ( <span class="type"><a href="qobject.html">QObject</a></span> * <i>parent</i> = 0 )</h3>
<p>Constructs an empty buffer with the given <i>parent</i>. You can call <a href="qbuffer.html#setData">setData</a>() to fill the buffer with data, or you can open it in write mode and use <a href="qiodevice.html#write">write</a>().</p>
<p><b>See also </b><a href="qbuffer.html#open">open</a>().</p>
<!-- @@@QBuffer -->
<!-- $$$QBuffer$$$QBufferQByteArray*QObject* -->
<h3 class="fn"><a name="QBuffer-2"></a>QBuffer::<span class="name">QBuffer</span> ( <span class="type"><a href="qbytearray.html">QByteArray</a></span> * <i>byteArray</i>, <span class="type"><a href="qobject.html">QObject</a></span> * <i>parent</i> = 0 )</h3>
<p>Constructs a <a href="qbuffer.html">QBuffer</a> that uses the <a href="qbytearray.html">QByteArray</a> pointed to by <i>byteArray</i> as its internal buffer, and with the given <i>parent</i>. The caller is responsible for ensuring that <i>byteArray</i> remains valid until the <a href="qbuffer.html">QBuffer</a> is destroyed, or until <a href="qbuffer.html#setBuffer">setBuffer</a>() is called to change the buffer. <a href="qbuffer.html">QBuffer</a> doesn't take ownership of the <a href="qbytearray.html">QByteArray</a>.</p>
<p>If you open the buffer in write-only mode or read-write mode and write something into the <a href="qbuffer.html">QBuffer</a>, <i>byteArray</i> will be modified.</p>
<p>Example:</p>
<pre class="cpp"> <span class="type"><a href="qbytearray.html">QByteArray</a></span> byteArray(<span class="string">"abc"</span>);
<span class="type"><a href="qbuffer.html">QBuffer</a></span> buffer(<span class="operator">&</span>byteArray);
buffer<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>WriteOnly);
buffer<span class="operator">.</span>seek(<span class="number">3</span>);
buffer<span class="operator">.</span>write(<span class="string">"def"</span><span class="operator">,</span> <span class="number">3</span>);
buffer<span class="operator">.</span>close();
<span class="comment">// byteArray == "abcdef"</span></pre>
<p><b>See also </b><a href="qbuffer.html#open">open</a>(), <a href="qbuffer.html#setBuffer">setBuffer</a>(), and <a href="qbuffer.html#setData">setData</a>().</p>
<!-- @@@QBuffer -->
<!-- $$$~QBuffer[overload1]$$$~QBuffer -->
<h3 class="fn"><a name="dtor.QBuffer"></a>QBuffer::<span class="name">~QBuffer</span> ()</h3>
<p>Destroys the buffer.</p>
<!-- @@@~QBuffer -->
<!-- $$$atEnd[overload1]$$$atEnd -->
<h3 class="fn"><a name="atEnd"></a><span class="type">bool</span> QBuffer::<span class="name">atEnd</span> () const<tt> [virtual]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#atEnd">QIODevice::atEnd</a>().</p>
<!-- @@@atEnd -->
<!-- $$$buffer[overload1]$$$buffer -->
<h3 class="fn"><a name="buffer"></a><span class="type"><a href="qbytearray.html">QByteArray</a></span> & QBuffer::<span class="name">buffer</span> ()</h3>
<p>Returns a reference to the <a href="qbuffer.html">QBuffer</a>'s internal buffer. You can use it to modify the <a href="qbytearray.html">QByteArray</a> behind the <a href="qbuffer.html">QBuffer</a>'s back.</p>
<p><b>See also </b><a href="qbuffer.html#setBuffer">setBuffer</a>() and <a href="qbuffer.html#data">data</a>().</p>
<!-- @@@buffer -->
<!-- $$$buffer$$$buffer -->
<h3 class="fn"><a name="buffer-2"></a>const <span class="type"><a href="qbytearray.html">QByteArray</a></span> & QBuffer::<span class="name">buffer</span> () const</h3>
<p>This is an overloaded function.</p>
<p>This is the same as <a href="qbuffer.html#data">data</a>().</p>
<!-- @@@buffer -->
<!-- $$$canReadLine[overload1]$$$canReadLine -->
<h3 class="fn"><a name="canReadLine"></a><span class="type">bool</span> QBuffer::<span class="name">canReadLine</span> () const<tt> [virtual]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#canReadLine">QIODevice::canReadLine</a>().</p>
<!-- @@@canReadLine -->
<!-- $$$close[overload1]$$$close -->
<h3 class="fn"><a name="close"></a><span class="type">void</span> QBuffer::<span class="name">close</span> ()<tt> [virtual]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#close">QIODevice::close</a>().</p>
<!-- @@@close -->
<!-- $$$data[overload1]$$$data -->
<h3 class="fn"><a name="data"></a>const <span class="type"><a href="qbytearray.html">QByteArray</a></span> & QBuffer::<span class="name">data</span> () const</h3>
<p>Returns the data contained in the buffer.</p>
<p>This is the same as <a href="qbuffer.html#buffer">buffer</a>().</p>
<p><b>See also </b><a href="qbuffer.html#setData">setData</a>() and <a href="qbuffer.html#setBuffer">setBuffer</a>().</p>
<!-- @@@data -->
<!-- $$$open[overload1]$$$openOpenMode -->
<h3 class="fn"><a name="open"></a><span class="type">bool</span> QBuffer::<span class="name">open</span> ( <span class="type"><a href="qiodevice.html#OpenModeFlag-enum">OpenMode</a></span> <i>flags</i> )<tt> [virtual]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#open">QIODevice::open</a>().</p>
<!-- @@@open -->
<!-- $$$pos[overload1]$$$pos -->
<h3 class="fn"><a name="pos"></a><span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> QBuffer::<span class="name">pos</span> () const<tt> [virtual]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#pos">QIODevice::pos</a>().</p>
<!-- @@@pos -->
<!-- $$$readData[overload1]$$$readDatachar*qint64 -->
<h3 class="fn"><a name="readData"></a><span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> QBuffer::<span class="name">readData</span> ( <span class="type">char</span> * <i>data</i>, <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> <i>len</i> )<tt> [virtual protected]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#readData">QIODevice::readData</a>().</p>
<!-- @@@readData -->
<!-- $$$seek[overload1]$$$seekqint64 -->
<h3 class="fn"><a name="seek"></a><span class="type">bool</span> QBuffer::<span class="name">seek</span> ( <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> <i>pos</i> )<tt> [virtual]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#seek">QIODevice::seek</a>().</p>
<!-- @@@seek -->
<!-- $$$setBuffer[overload1]$$$setBufferQByteArray* -->
<h3 class="fn"><a name="setBuffer"></a><span class="type">void</span> QBuffer::<span class="name">setBuffer</span> ( <span class="type"><a href="qbytearray.html">QByteArray</a></span> * <i>byteArray</i> )</h3>
<p>Makes <a href="qbuffer.html">QBuffer</a> uses the <a href="qbytearray.html">QByteArray</a> pointed to by <i>byteArray</i> as its internal buffer. The caller is responsible for ensuring that <i>byteArray</i> remains valid until the <a href="qbuffer.html">QBuffer</a> is destroyed, or until setBuffer() is called to change the buffer. <a href="qbuffer.html">QBuffer</a> doesn't take ownership of the <a href="qbytearray.html">QByteArray</a>.</p>
<p>Does nothing if <a href="qiodevice.html#isOpen">isOpen</a>() is true.</p>
<p>If you open the buffer in write-only mode or read-write mode and write something into the <a href="qbuffer.html">QBuffer</a>, <i>byteArray</i> will be modified.</p>
<p>Example:</p>
<pre class="cpp"> <span class="type"><a href="qbytearray.html">QByteArray</a></span> byteArray(<span class="string">"abc"</span>);
<span class="type"><a href="qbuffer.html">QBuffer</a></span> buffer;
buffer<span class="operator">.</span>setBuffer(<span class="operator">&</span>byteArray);
buffer<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>WriteOnly);
buffer<span class="operator">.</span>seek(<span class="number">3</span>);
buffer<span class="operator">.</span>write(<span class="string">"def"</span><span class="operator">,</span> <span class="number">3</span>);
buffer<span class="operator">.</span>close();
<span class="comment">// byteArray == "abcdef"</span></pre>
<p>If <i>byteArray</i> is 0, the buffer creates its own internal <a href="qbytearray.html">QByteArray</a> to work on. This byte array is initially empty.</p>
<p><b>See also </b><a href="qbuffer.html#buffer">buffer</a>(), <a href="qbuffer.html#setData">setData</a>(), and <a href="qbuffer.html#open">open</a>().</p>
<!-- @@@setBuffer -->
<!-- $$$setData[overload1]$$$setDataconstQByteArray& -->
<h3 class="fn"><a name="setData"></a><span class="type">void</span> QBuffer::<span class="name">setData</span> ( const <span class="type"><a href="qbytearray.html">QByteArray</a></span> & <i>data</i> )</h3>
<p>Sets the contents of the internal buffer to be <i>data</i>. This is the same as assigning <i>data</i> to <a href="qbuffer.html#buffer">buffer</a>().</p>
<p>Does nothing if <a href="qiodevice.html#isOpen">isOpen</a>() is true.</p>
<p><b>See also </b><a href="qbuffer.html#data">data</a>() and <a href="qbuffer.html#setBuffer">setBuffer</a>().</p>
<!-- @@@setData -->
<!-- $$$setData$$$setDataconstchar*int -->
<h3 class="fn"><a name="setData-2"></a><span class="type">void</span> QBuffer::<span class="name">setData</span> ( const <span class="type">char</span> * <i>data</i>, <span class="type">int</span> <i>size</i> )</h3>
<p>This is an overloaded function.</p>
<p>Sets the contents of the internal buffer to be the first <i>size</i> bytes of <i>data</i>.</p>
<!-- @@@setData -->
<!-- $$$size[overload1]$$$size -->
<h3 class="fn"><a name="size"></a><span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> QBuffer::<span class="name">size</span> () const<tt> [virtual]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#size">QIODevice::size</a>().</p>
<!-- @@@size -->
<!-- $$$writeData[overload1]$$$writeDataconstchar*qint64 -->
<h3 class="fn"><a name="writeData"></a><span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> QBuffer::<span class="name">writeData</span> ( const <span class="type">char</span> * <i>data</i>, <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> <i>len</i> )<tt> [virtual protected]</tt></h3>
<p>Reimplemented from <a href="qiodevice.html#writeData">QIODevice::writeData</a>().</p>
<!-- @@@writeData -->
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