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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en_US" lang="en_US">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<!-- qdeclarativeengine.cpp -->
<title>Qt 4.8: QML QtObject Element</title>
<link rel="stylesheet" type="text/css" href="style/offline.css" />
</head>
<body>
<div class="header" id="qtdocheader">
<div class="content">
<a href="index.html" class="qtref"><span>Qt Reference Documentation</span></a>
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<ul>
<li class="first"><a href="index.html">Home</a></li>
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<li><a href="qdeclarativeelements.html">QML Elements</a></li>
<li>QML QtObject Element</li>
</ul>
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</div>
<div class="content mainContent">
<div class="toc">
<h3><a name="toc">Contents</a></h3>
<ul>
<li class="level1"><a href="#properties">Properties</a></li>
<li class="level1"><a href="#details">Detailed Description</a></li>
</ul>
</div>
<h1 class="title">QML QtObject Element</h1>
<span class="subtitle"></span>
<!-- $$$QML:QtObject-brief -->
<p>The QtObject element is the most basic element in QML. <a href="#details">More...</a></p>
<!-- @@@QML:QtObject -->
<p>QtObject instantiates the C++ class <a href="qobject.html">QObject</a></p>
<p>This element was introduced in Qt 4.7.</p>
<ul>
<li><a href="qml-qtobject-members.html">List of all members, including inherited members</a></li>
</ul>
<a name="properties"></a>
<h2>Properties</h2>
<ul>
<li class="fn"><b><b><a href="qml-qtobject.html#objectName-prop">objectName</a></b></b> : string</li>
</ul>
<!-- $$$QML:QtObject-description -->
<a name="details"></a>
<h2>Detailed Description</h2>
<p>The QtObject element is a non-visual element which contains only the <a href="qml-qtobject.html#objectName-prop">objectName</a> property.</p>
<p>It can be useful to create a QtObject if you need an extremely lightweight element to enclose a set of custom properties:</p>
<pre class="qml"> import QtQuick 1.0
<span class="type"><a href="qml-item.html">Item</a></span> {
<span class="type">QtObject</span> {
<span class="name">id</span>: <span class="name">attributes</span>
property <span class="type"><a href="qml-string.html">string</a></span> <span class="name">name</span>
property <span class="type"><a href="qml-int.html">int</a></span> <span class="name">size</span>
property <span class="type"><a href="qml-variant.html">variant</a></span> <span class="name">attributes</span>
}
<span class="type"><a href="qml-text.html">Text</a></span> { <span class="name">text</span>: <span class="name">attributes</span>.<span class="name">name</span> }
}</pre>
<p>It can also be useful for C++ integration, as it is just a plain <a href="qobject.html">QObject</a>. See the <a href="qobject.html">QObject</a> documentation for further details.</p>
<!-- @@@QML:QtObject -->
<h2>Property Documentation</h2>
<!-- $$$objectName -->
<div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="objectName-prop"></a><span class="name">objectName</span> : <span class="type"><a href="qml-string.html">string</a></span></p></td></tr></table></div><div class="qmldoc"><p>This property holds the <a href="qobject.html#objectName-prop">QObject::objectName</a> for this specific object instance.</p>
<p>This allows a C++ application to locate an item within a QML component using the <a href="qobject.html#findChild">QObject::findChild()</a> method. For example, the following C++ application locates the child <a href="qml-rectangle.html">Rectangle</a> item and dynamically changes its <tt>color</tt> value:</p>
<pre class="qml"> <span class="comment">// MyRect.qml</span>
import QtQuick 1.0
<span class="type"><a href="qml-item.html">Item</a></span> {
<span class="name">width</span>: <span class="number">200</span>; <span class="name">height</span>: <span class="number">200</span>
<span class="type"><a href="qml-rectangle.html">Rectangle</a></span> {
<span class="name">anchors</span>.fill: <span class="name">parent</span>
<span class="name">color</span>: <span class="string">"red"</span>
<span class="name">objectName</span>: <span class="string">"myRect"</span>
}
}</pre>
<pre class="cpp"> <span class="comment">// main.cpp</span>
<span class="type"><a href="qdeclarativeview.html">QDeclarativeView</a></span> view;
view<span class="operator">.</span>setSource(<span class="type"><a href="qurl.html">QUrl</a></span><span class="operator">::</span>fromLocalFile(<span class="string">"MyRect.qml"</span>));
view<span class="operator">.</span>show();
<span class="type"><a href="qdeclarativeitem.html">QDeclarativeItem</a></span> <span class="operator">*</span>item <span class="operator">=</span> view<span class="operator">.</span>rootObject()<span class="operator">-</span><span class="operator">></span>findChild<span class="operator"><</span><span class="type"><a href="qdeclarativeitem.html">QDeclarativeItem</a></span><span class="operator">*</span><span class="operator">></span>(<span class="string">"myRect"</span>);
<span class="keyword">if</span> (item)
item<span class="operator">-</span><span class="operator">></span>setProperty(<span class="string">"color"</span><span class="operator">,</span> <span class="type"><a href="qcolor.html">QColor</a></span>(<span class="type"><a href="qt.html">Qt</a></span><span class="operator">::</span>yellow));</pre>
</div></div><!-- @@@objectName -->
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