<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qml-extending.qdoc --> <title>Extending QML - Adding Types Example | Qt QML 5.9</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 5.9</td><td ><a href="qtqml-index.html">Qt QML</a></td><td ><a href="qmlextendingexamples.html">Qt QML Examples</a></td><td >Extending QML - Adding Types Example</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#declare-the-person-class">Declare the Person Class</a></li> <li class="level1"><a href="#define-the-person-class">Define the Person Class</a></li> <li class="level1"><a href="#running-the-example">Running the Example</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">Extending QML - Adding Types Example</h1> <span class="subtitle"></span> <!-- $$$referenceexamples/adding-description --> <div class="descr"> <a name="details"></a> <p>The Adding Types Example shows how to add a new object type, <code>Person</code>, to QML. The <code>Person</code> type can be used from QML like this:</p> <pre class="qml"> import People 1.0 <span class="type">Person</span> { <span class="name">name</span>: <span class="string">"Bob Jones"</span> <span class="name">shoeSize</span>: <span class="number">12</span> } </pre> <a name="declare-the-person-class"></a> <h2 id="declare-the-person-class">Declare the Person Class</h2> <p>All QML types map to C++ types. Here we declare a basic C++ Person class with the two properties we want accessible on the QML type - name and shoeSize. Although in this example we use the same name for the C++ class as the QML type, the C++ class can be named differently, or appear in a namespace.</p> <pre class="cpp"> <span class="keyword">class</span> Person : <span class="keyword">public</span> <span class="type">QObject</span> { Q_OBJECT Q_PROPERTY(<span class="type">QString</span> name READ name WRITE setName) Q_PROPERTY(<span class="type">int</span> shoeSize READ shoeSize WRITE setShoeSize) <span class="keyword">public</span>: Person(<span class="type">QObject</span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>); <span class="type">QString</span> name() <span class="keyword">const</span>; <span class="type">void</span> setName(<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>); <span class="type">int</span> shoeSize() <span class="keyword">const</span>; <span class="type">void</span> setShoeSize(<span class="type">int</span>); <span class="keyword">private</span>: <span class="type">QString</span> m_name; <span class="type">int</span> m_shoeSize; }; </pre> <a name="define-the-person-class"></a> <h2 id="define-the-person-class">Define the Person Class</h2> <pre class="cpp"> Person<span class="operator">::</span>Person(<span class="type">QObject</span> <span class="operator">*</span>parent) : <span class="type">QObject</span>(parent)<span class="operator">,</span> m_shoeSize(<span class="number">0</span>) { } <span class="type">QString</span> Person<span class="operator">::</span>name() <span class="keyword">const</span> { <span class="keyword">return</span> m_name; } <span class="type">void</span> Person<span class="operator">::</span>setName(<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>n) { m_name <span class="operator">=</span> n; } <span class="type">int</span> Person<span class="operator">::</span>shoeSize() <span class="keyword">const</span> { <span class="keyword">return</span> m_shoeSize; } <span class="type">void</span> Person<span class="operator">::</span>setShoeSize(<span class="type">int</span> s) { m_shoeSize <span class="operator">=</span> s; } </pre> <p>The Person class implementation is quite basic. The property accessors simply return members of the object instance.</p> <p>The <code>main.cpp</code> file also calls the <code>qmlRegisterType()</code> function to register the <code>Person</code> type with QML as a type in the People library version 1.0, and defines the mapping between the C++ and QML class names.</p> <a name="running-the-example"></a> <h2 id="running-the-example">Running the Example</h2> <p>The main.cpp file in the example includes a simple shell application that loads and runs the QML snippet shown at the beginning of this page.</p> <p>Files:</p> <ul> <li><a href="qtqml-referenceexamples-adding-example-qml.html">referenceexamples/adding/example.qml</a></li> <li><a href="qtqml-referenceexamples-adding-person-cpp.html">referenceexamples/adding/person.cpp</a></li> <li><a href="qtqml-referenceexamples-adding-person-h.html">referenceexamples/adding/person.h</a></li> <li><a href="qtqml-referenceexamples-adding-main-cpp.html">referenceexamples/adding/main.cpp</a></li> <li><a href="qtqml-referenceexamples-adding-adding-pro.html">referenceexamples/adding/adding.pro</a></li> <li><a href="qtqml-referenceexamples-adding-adding-qrc.html">referenceexamples/adding/adding.qrc</a></li> </ul> </div> <!-- @@@referenceexamples/adding --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2017 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>