<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>dialog.cpp Example File | Qt Network 5.12.6</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.12</td><td ><a href="qtnetwork-index.html">Qt Network</a></td><td ><a href="qtnetwork-loopback-example.html">Loopback Example</a></td><td >dialog.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtnetwork-index.html">Qt 5.12.6 Reference Documentation</a></td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"><div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">dialog.cpp Example File</h1> <span class="subtitle">loopback/dialog.cpp</span> <!-- $$$loopback/dialog.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include "dialog.h"</span> <span class="preprocessor">#include <QtNetwork></span> <span class="preprocessor">#include <QtWidgets></span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="type">int</span> TotalBytes <span class="operator">=</span> <span class="number">50</span> <span class="operator">*</span> <span class="number">1024</span> <span class="operator">*</span> <span class="number">1024</span>; <span class="keyword">static</span> <span class="keyword">const</span> <span class="type">int</span> PayloadSize <span class="operator">=</span> <span class="number">64</span> <span class="operator">*</span> <span class="number">1024</span>; <span class="comment">// 64 KB</span> Dialog<span class="operator">::</span>Dialog(<span class="type">QWidget</span> <span class="operator">*</span>parent) : <span class="type">QDialog</span>(parent) { clientProgressBar <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QProgressBar</span>; clientStatusLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QLabel</span>(tr(<span class="string">"Client ready"</span>)); serverProgressBar <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QProgressBar</span>; serverStatusLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QLabel</span>(tr(<span class="string">"Server ready"</span>)); startButton <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QPushButton</span>(tr(<span class="string">"&Start"</span>)); quitButton <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QPushButton</span>(tr(<span class="string">"&Quit"</span>)); buttonBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QDialogButtonBox</span>; buttonBox<span class="operator">-</span><span class="operator">></span>addButton(startButton<span class="operator">,</span> <span class="type">QDialogButtonBox</span><span class="operator">::</span>ActionRole); buttonBox<span class="operator">-</span><span class="operator">></span>addButton(quitButton<span class="operator">,</span> <span class="type">QDialogButtonBox</span><span class="operator">::</span>RejectRole); connect(startButton<span class="operator">,</span> <span class="operator">&</span><span class="type">QAbstractButton</span><span class="operator">::</span>clicked<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Dialog<span class="operator">::</span>start); connect(quitButton<span class="operator">,</span> <span class="operator">&</span><span class="type">QAbstractButton</span><span class="operator">::</span>clicked<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span><span class="type">QWidget</span><span class="operator">::</span>close); connect(<span class="operator">&</span>tcpServer<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qtcpserver.html">QTcpServer</a></span><span class="operator">::</span>newConnection<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Dialog<span class="operator">::</span>acceptConnection); connect(<span class="operator">&</span>tcpClient<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qabstractsocket.html">QAbstractSocket</a></span><span class="operator">::</span>connected<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Dialog<span class="operator">::</span>startTransfer); connect(<span class="operator">&</span>tcpClient<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="../qtcore/qiodevice.html">QIODevice</a></span><span class="operator">::</span>bytesWritten<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Dialog<span class="operator">::</span>updateClientProgress); connect(<span class="operator">&</span>tcpClient<span class="operator">,</span> <span class="type">QOverload</span><span class="operator"><</span><span class="type"><a href="qabstractsocket.html">QAbstractSocket</a></span><span class="operator">::</span>SocketError<span class="operator">></span><span class="operator">::</span>of(<span class="operator">&</span><span class="type"><a href="qabstractsocket.html">QAbstractSocket</a></span><span class="operator">::</span>error)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Dialog<span class="operator">::</span>displayError); <span class="type">QVBoxLayout</span> <span class="operator">*</span>mainLayout <span class="operator">=</span> <span class="keyword">new</span> <span class="type">QVBoxLayout</span>; mainLayout<span class="operator">-</span><span class="operator">></span>addWidget(clientProgressBar); mainLayout<span class="operator">-</span><span class="operator">></span>addWidget(clientStatusLabel); mainLayout<span class="operator">-</span><span class="operator">></span>addWidget(serverProgressBar); mainLayout<span class="operator">-</span><span class="operator">></span>addWidget(serverStatusLabel); mainLayout<span class="operator">-</span><span class="operator">></span>addStretch(<span class="number">1</span>); mainLayout<span class="operator">-</span><span class="operator">></span>addSpacing(<span class="number">10</span>); mainLayout<span class="operator">-</span><span class="operator">></span>addWidget(buttonBox); setLayout(mainLayout); setWindowTitle(tr(<span class="string">"Loopback"</span>)); } <span class="type">void</span> Dialog<span class="operator">::</span>start() { startButton<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); <span class="preprocessor">#ifndef QT_NO_CURSOR</span> <span class="type">QApplication</span><span class="operator">::</span>setOverrideCursor(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>WaitCursor); <span class="preprocessor">#endif</span> bytesWritten <span class="operator">=</span> <span class="number">0</span>; bytesReceived <span class="operator">=</span> <span class="number">0</span>; <span class="keyword">while</span> (<span class="operator">!</span>tcpServer<span class="operator">.</span>isListening() <span class="operator">&</span><span class="operator">&</span> <span class="operator">!</span>tcpServer<span class="operator">.</span>listen()) { <span class="type">QMessageBox</span><span class="operator">::</span>StandardButton ret <span class="operator">=</span> <span class="type">QMessageBox</span><span class="operator">::</span>critical(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Loopback"</span>)<span class="operator">,</span> tr(<span class="string">"Unable to start the test: %1."</span>) <span class="operator">.</span>arg(tcpServer<span class="operator">.</span>errorString())<span class="operator">,</span> <span class="type">QMessageBox</span><span class="operator">::</span>Retry <span class="operator">|</span> <span class="type">QMessageBox</span><span class="operator">::</span>Cancel); <span class="keyword">if</span> (ret <span class="operator">=</span><span class="operator">=</span> <span class="type">QMessageBox</span><span class="operator">::</span>Cancel) <span class="keyword">return</span>; } serverStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Listening"</span>)); clientStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Connecting"</span>)); tcpClient<span class="operator">.</span>connectToHost(<span class="type"><a href="qhostaddress.html">QHostAddress</a></span><span class="operator">::</span>LocalHost<span class="operator">,</span> tcpServer<span class="operator">.</span>serverPort()); } <span class="type">void</span> Dialog<span class="operator">::</span>acceptConnection() { tcpServerConnection <span class="operator">=</span> tcpServer<span class="operator">.</span>nextPendingConnection(); <span class="keyword">if</span> (<span class="operator">!</span>tcpServerConnection) { serverStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Error: got invalid pending connection!"</span>)); <span class="keyword">return</span>; } connect(tcpServerConnection<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="../qtcore/qiodevice.html">QIODevice</a></span><span class="operator">::</span>readyRead<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Dialog<span class="operator">::</span>updateServerProgress); connect(tcpServerConnection<span class="operator">,</span> <span class="type">QOverload</span><span class="operator"><</span><span class="type"><a href="qabstractsocket.html">QAbstractSocket</a></span><span class="operator">::</span>SocketError<span class="operator">></span><span class="operator">::</span>of(<span class="operator">&</span><span class="type"><a href="qabstractsocket.html">QAbstractSocket</a></span><span class="operator">::</span>error)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Dialog<span class="operator">::</span>displayError); connect(tcpServerConnection<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qtcpsocket.html">QTcpSocket</a></span><span class="operator">::</span>disconnected<span class="operator">,</span> tcpServerConnection<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qtcpsocket.html">QTcpSocket</a></span><span class="operator">::</span>deleteLater); serverStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Accepted connection"</span>)); tcpServer<span class="operator">.</span>close(); } <span class="type">void</span> Dialog<span class="operator">::</span>startTransfer() { <span class="comment">// called when the TCP client connected to the loopback server</span> bytesToWrite <span class="operator">=</span> TotalBytes <span class="operator">-</span> <span class="type">int</span>(tcpClient<span class="operator">.</span>write(<span class="type"><a href="../qtcore/qbytearray.html">QByteArray</a></span>(PayloadSize<span class="operator">,</span> <span class="char">'@'</span>))); clientStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Connected"</span>)); } <span class="type">void</span> Dialog<span class="operator">::</span>updateServerProgress() { bytesReceived <span class="operator">+</span><span class="operator">=</span> <span class="type">int</span>(tcpServerConnection<span class="operator">-</span><span class="operator">></span>bytesAvailable()); tcpServerConnection<span class="operator">-</span><span class="operator">></span>readAll(); serverProgressBar<span class="operator">-</span><span class="operator">></span>setMaximum(TotalBytes); serverProgressBar<span class="operator">-</span><span class="operator">></span>setValue(bytesReceived); serverStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Received %1MB"</span>) <span class="operator">.</span>arg(bytesReceived <span class="operator">/</span> (<span class="number">1024</span> <span class="operator">*</span> <span class="number">1024</span>))); <span class="keyword">if</span> (bytesReceived <span class="operator">=</span><span class="operator">=</span> TotalBytes) { tcpServerConnection<span class="operator">-</span><span class="operator">></span>close(); startButton<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">true</span>); <span class="preprocessor">#ifndef QT_NO_CURSOR</span> <span class="type">QApplication</span><span class="operator">::</span>restoreOverrideCursor(); <span class="preprocessor">#endif</span> } } <span class="type">void</span> Dialog<span class="operator">::</span>updateClientProgress(<span class="type"><a href="../qtcore/qtglobal.html#qint64-typedef">qint64</a></span> numBytes) { <span class="comment">// called when the TCP client has written some bytes</span> bytesWritten <span class="operator">+</span><span class="operator">=</span> <span class="type">int</span>(numBytes); <span class="comment">// only write more if not finished and when the Qt write buffer is below a certain size.</span> <span class="keyword">if</span> (bytesToWrite <span class="operator">></span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> tcpClient<span class="operator">.</span>bytesToWrite() <span class="operator"><</span><span class="operator">=</span> <span class="number">4</span> <span class="operator">*</span> PayloadSize) bytesToWrite <span class="operator">-</span><span class="operator">=</span> tcpClient<span class="operator">.</span>write(<span class="type"><a href="../qtcore/qbytearray.html">QByteArray</a></span>(<a href="../qtcore/qtglobal.html#qMin">qMin</a>(bytesToWrite<span class="operator">,</span> PayloadSize)<span class="operator">,</span> <span class="char">'@'</span>)); clientProgressBar<span class="operator">-</span><span class="operator">></span>setMaximum(TotalBytes); clientProgressBar<span class="operator">-</span><span class="operator">></span>setValue(bytesWritten); clientStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Sent %1MB"</span>)<span class="operator">.</span>arg(bytesWritten <span class="operator">/</span> (<span class="number">1024</span> <span class="operator">*</span> <span class="number">1024</span>))); } <span class="type">void</span> Dialog<span class="operator">::</span>displayError(<span class="type"><a href="qabstractsocket.html">QAbstractSocket</a></span><span class="operator">::</span>SocketError socketError) { <span class="keyword">if</span> (socketError <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qtcpsocket.html">QTcpSocket</a></span><span class="operator">::</span>RemoteHostClosedError) <span class="keyword">return</span>; <span class="type">QMessageBox</span><span class="operator">::</span>information(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Network error"</span>)<span class="operator">,</span> tr(<span class="string">"The following error occurred: %1."</span>) <span class="operator">.</span>arg(tcpClient<span class="operator">.</span>errorString())); tcpClient<span class="operator">.</span>close(); tcpServer<span class="operator">.</span>close(); clientProgressBar<span class="operator">-</span><span class="operator">></span>reset(); serverProgressBar<span class="operator">-</span><span class="operator">></span>reset(); clientStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Client ready"</span>)); serverStatusLabel<span class="operator">-</span><span class="operator">></span>setText(tr(<span class="string">"Server ready"</span>)); startButton<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">true</span>); <span class="preprocessor">#ifndef QT_NO_CURSOR</span> <span class="type">QApplication</span><span class="operator">::</span>restoreOverrideCursor(); <span class="preprocessor">#endif</span> } </pre> </div> <!-- @@@loopback/dialog.cpp --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>