<?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>main.cpp Example File | Qt 5.12</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 ><a href="index.html">Qt 5.12</a></td><td ><a href="qtdoc-demos-photosurface-example.html">Qt Quick Demo - Photo Surface</a></td><td >main.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.12.6 Reference Documentation</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">main.cpp Example File</h1> <span class="subtitle">demos/photosurface/main.cpp</span> <!-- $$$demos/photosurface/main.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2017 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">#ifdef QT_WIDGETS_LIB</span> <span class="preprocessor">#include <QtWidgets/QApplication></span> <span class="preprocessor">#else</span> <span class="preprocessor">#include <QtGui/QGuiApplication></span> <span class="preprocessor">#endif</span> <span class="preprocessor">#include <QtQml/QQmlApplicationEngine></span> <span class="preprocessor">#include <QtQml/QQmlContext></span> <span class="preprocessor">#include <QtQuick/QQuickWindow></span> <span class="preprocessor">#include <QtGui/QImageReader></span> <span class="preprocessor">#include <QtCore/QCommandLineParser></span> <span class="preprocessor">#include <QtCore/QCommandLineOption></span> <span class="preprocessor">#include <QtCore/QDebug></span> <span class="preprocessor">#include <QtCore/QDir></span> <span class="preprocessor">#include <QtCore/QMimeDatabase></span> <span class="preprocessor">#include <QtCore/QStandardPaths></span> <span class="preprocessor">#include <QtCore/QUrl></span> <span class="keyword">static</span> <span class="type">QStringList</span> imageNameFilters() { <span class="type">QStringList</span> result; <span class="type">QMimeDatabase</span> mimeDatabase; <span class="keyword">const</span> <span class="keyword">auto</span> supportedMimeTypes <span class="operator">=</span> <span class="type">QImageReader</span><span class="operator">::</span>supportedMimeTypes(); <span class="keyword">for</span> (<span class="keyword">const</span> <span class="type">QByteArray</span> <span class="operator">&</span>m : supportedMimeTypes) { <span class="keyword">const</span> <span class="keyword">auto</span> suffixes <span class="operator">=</span> mimeDatabase<span class="operator">.</span>mimeTypeForName(m)<span class="operator">.</span>suffixes(); <span class="keyword">for</span> (<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>suffix : suffixes) result<span class="operator">.</span>append(QLatin1String(<span class="string">"*."</span>) <span class="operator">+</span> suffix); } <span class="keyword">return</span> result; } <span class="type">int</span> main(<span class="type">int</span> argc<span class="operator">,</span> <span class="type">char</span><span class="operator">*</span> argv<span class="operator">[</span><span class="operator">]</span>) { <span class="comment">// The reason to use QApplication is that QWidget-based dialogs</span> <span class="comment">// are the native dialogs on Qt-based platforms like KDE,</span> <span class="comment">// but they cannot be instantiated if this is a QGuiApplication.</span> <span class="preprocessor">#ifdef QT_WIDGETS_LIB</span> <span class="type">QApplication</span> app(argc<span class="operator">,</span> argv); <span class="preprocessor">#else</span> <span class="type">QGuiApplication</span> app(argc<span class="operator">,</span> argv); <span class="preprocessor">#endif</span> <span class="type">QQuickWindow</span><span class="operator">::</span>setDefaultAlphaBuffer(<span class="keyword">true</span>); <span class="type">QCoreApplication</span><span class="operator">::</span>setApplicationName(<span class="type">QStringLiteral</span>(<span class="string">"Photosurface"</span>)); <span class="type">QCoreApplication</span><span class="operator">::</span>setOrganizationName(<span class="type">QStringLiteral</span>(<span class="string">"QtProject"</span>)); <span class="type">QCoreApplication</span><span class="operator">::</span>setApplicationVersion(QLatin1String(QT_VERSION_STR)); <span class="type">QCommandLineParser</span> parser; parser<span class="operator">.</span>setApplicationDescription(<span class="type">QStringLiteral</span>(<span class="string">"Qt Quick Demo - Photo Surface"</span>)); parser<span class="operator">.</span>addHelpOption(); parser<span class="operator">.</span>addVersionOption(); parser<span class="operator">.</span>addPositionalArgument(<span class="type">QStringLiteral</span>(<span class="string">"directory"</span>)<span class="operator">,</span> <span class="type">QStringLiteral</span>(<span class="string">"The image directory or URL to show."</span>)); parser<span class="operator">.</span>process(app); <span class="type">QUrl</span> initialUrl; <span class="keyword">if</span> (<span class="operator">!</span>parser<span class="operator">.</span>positionalArguments()<span class="operator">.</span>isEmpty()) { initialUrl <span class="operator">=</span> <span class="type">QUrl</span><span class="operator">::</span>fromUserInput(parser<span class="operator">.</span>positionalArguments()<span class="operator">.</span>first()<span class="operator">,</span> <span class="type">QDir</span><span class="operator">::</span>currentPath()<span class="operator">,</span> <span class="type">QUrl</span><span class="operator">::</span>AssumeLocalFile); <span class="keyword">if</span> (<span class="operator">!</span>initialUrl<span class="operator">.</span>isValid()) { qWarning()<span class="operator">.</span>nospace() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Invalid argument: \""</span> <span class="operator"><</span><span class="operator"><</span> parser<span class="operator">.</span>positionalArguments()<span class="operator">.</span>first() <span class="operator"><</span><span class="operator"><</span> <span class="string">"\": "</span> <span class="operator"><</span><span class="operator"><</span> initialUrl<span class="operator">.</span>errorString(); <span class="keyword">return</span> <span class="number">1</span>; } } <span class="keyword">const</span> <span class="type">QStringList</span> nameFilters <span class="operator">=</span> imageNameFilters(); <span class="type">QQmlApplicationEngine</span> engine; <span class="type">QQmlContext</span> <span class="operator">*</span>context <span class="operator">=</span> engine<span class="operator">.</span>rootContext(); <span class="type">QUrl</span> picturesLocationUrl <span class="operator">=</span> <span class="type">QUrl</span><span class="operator">::</span>fromLocalFile(<span class="type">QDir</span><span class="operator">::</span>homePath()); <span class="keyword">const</span> <span class="type">QStringList</span> picturesLocations <span class="operator">=</span> <span class="type">QStandardPaths</span><span class="operator">::</span>standardLocations(<span class="type">QStandardPaths</span><span class="operator">::</span>PicturesLocation); <span class="keyword">if</span> (<span class="operator">!</span>picturesLocations<span class="operator">.</span>isEmpty()) { picturesLocationUrl <span class="operator">=</span> <span class="type">QUrl</span><span class="operator">::</span>fromLocalFile(picturesLocations<span class="operator">.</span>first()); <span class="keyword">if</span> (initialUrl<span class="operator">.</span>isEmpty() <span class="operator">&</span><span class="operator">&</span> <span class="operator">!</span><span class="type">QDir</span>(picturesLocations<span class="operator">.</span>first())<span class="operator">.</span>entryInfoList(nameFilters<span class="operator">,</span> <span class="type">QDir</span><span class="operator">::</span>Files)<span class="operator">.</span>isEmpty()) { initialUrl <span class="operator">=</span> picturesLocationUrl; } } context<span class="operator">-</span><span class="operator">></span>setContextProperty(<span class="type">QStringLiteral</span>(<span class="string">"contextPicturesLocation"</span>)<span class="operator">,</span> picturesLocationUrl); context<span class="operator">-</span><span class="operator">></span>setContextProperty(<span class="type">QStringLiteral</span>(<span class="string">"contextInitialUrl"</span>)<span class="operator">,</span> initialUrl); context<span class="operator">-</span><span class="operator">></span>setContextProperty(<span class="type">QStringLiteral</span>(<span class="string">"contextImageNameFilters"</span>)<span class="operator">,</span> nameFilters); engine<span class="operator">.</span>load(<span class="type">QUrl</span>(<span class="string">"qrc:///photosurface.qml"</span>)); <span class="keyword">if</span> (engine<span class="operator">.</span>rootObjects()<span class="operator">.</span>isEmpty()) <span class="keyword">return</span> <span class="operator">-</span><span class="number">1</span>; <span class="keyword">return</span> app<span class="operator">.</span>exec(); } </pre> </div> <!-- @@@demos/photosurface/main.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>