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<!-- qstyleplugin.cpp -->
  <title>QStylePlugin Class | Qt Widgets 5.11</title>
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<td ><a href="../qtdoc/index.html">Qt 5.11</a></td><td ><a href="qtwidgets-index.html">Qt Widgets</a></td><td ><a href="qtwidgets-module.html">C++ Classes</a></td><td >QStylePlugin</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.11.2 Reference Documentation</td>
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<h3><a name="toc">Contents</a></h3>
<ul>
<li class="level1"><a href="#public-functions">Public Functions</a></li>
<li class="level1"><a href="#details">Detailed Description</a></li>
</ul>
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<h1 class="title">QStylePlugin Class</h1>
<!-- $$$QStylePlugin-brief -->
<p>The <a href="qstyleplugin.html">QStylePlugin</a> class provides an abstract base for custom <a href="qstyle.html">QStyle</a> plugins. <a href="#details">More...</a></p>
<!-- @@@QStylePlugin -->
<div class="table"><table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign">   <span class="preprocessor">#include &lt;QStylePlugin&gt;</span>
</td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += widgets</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherits:</td><td class="memItemRight bottomAlign"> <a href="../qtcore/qobject.html">QObject</a></td></tr></table></div><ul>
<li><a href="qstyleplugin-members.html">List of all members, including inherited members</a></li>
</ul>
<a name="public-functions"></a>
<h2 id="public-functions">Public Functions</h2>
<div class="table"><table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qstyleplugin.html#QStylePlugin">QStylePlugin</a></b>(QObject *<i>parent</i> = nullptr)</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual </td><td class="memItemRight bottomAlign"><b><a href="qstyleplugin.html#dtor.QStylePlugin">~QStylePlugin</a></b>()</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual QStyle *</td><td class="memItemRight bottomAlign"><b><a href="qstyleplugin.html#create">create</a></b>(const QString &amp;<i>key</i>) = 0</td></tr>
</table></div>
<ul>
<li class="fn">34 public functions inherited from <a href="../qtcore/qobject.html#public-functions">QObject</a></li>
</ul>
<h3>Additional Inherited Members</h3>
<ul>
<li class="fn">1 property inherited from <a href="../qtcore/qobject.html#properties">QObject</a></li>
<li class="fn">1 public slot inherited from <a href="../qtcore/qobject.html#public-slots">QObject</a></li>
<li class="fn">2 signals inherited from <a href="../qtcore/qobject.html#signals">QObject</a></li>
<li class="fn">1 public variable inherited from <a href="../qtcore/qobject.html#public-variables">QObject</a></li>
<li class="fn">10 static public members inherited from <a href="../qtcore/qobject.html#static-public-members">QObject</a></li>
<li class="fn">9 protected functions inherited from <a href="../qtcore/qobject.html#protected-functions">QObject</a></li>
<li class="fn">2 protected variables inherited from <a href="../qtcore/qobject.html#protected-variables">QObject</a></li>
</ul>
<a name="details"></a>
<!-- $$$QStylePlugin-description -->
<div class="descr">
<h2 id="details">Detailed Description</h2>
<p>The <a href="qstyleplugin.html">QStylePlugin</a> class provides an abstract base for custom <a href="qstyle.html">QStyle</a> plugins.</p>
<p><a href="qstyleplugin.html">QStylePlugin</a> is a simple plugin interface that makes it easy to create custom styles that can be loaded dynamically into applications using the <a href="qstylefactory.html">QStyleFactory</a> class.</p>
<p>Writing a style plugin is achieved by subclassing this base class, reimplementing the pure virtual <a href="qstyleplugin.html#create">create</a>() function, and exporting the class using the <a href="../qtcore/qtplugin.html#Q_PLUGIN_METADATA">Q_PLUGIN_METADATA</a>() macro.</p>
<pre class="cpp">

  <span class="keyword">class</span> MyStylePlugin : <span class="keyword">public</span> <span class="type"><a href="qstyleplugin.html#QStylePlugin">QStylePlugin</a></span>
  {
      Q_OBJECT
      Q_PLUGIN_METADATA(IID <span class="string">&quot;org.qt-project.Qt.QStyleFactoryInterface&quot;</span> FILE <span class="string">&quot;mystyleplugin.json&quot;</span>)
  <span class="keyword">public</span>:
      MyStylePlugin(<span class="type"><a href="../qtcore/qobject.html#QObject">QObject</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>);

      <span class="type"><a href="qstyle.html">QStyle</a></span> <span class="operator">*</span>create(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>key) override;
  };

</pre>
<p>The json metadata file <code>mystyleplugin.json</code> for the plugin needs to contain information about the names of the styles the plugins supports as follows:</p>
<pre class="cpp">

  { &quot;Keys&quot;: [ <span class="string">&quot;Rocket&quot;</span>, <span class="string">&quot;Starbuster&quot;</span> ] }

</pre>
<p>See <a href="../qtdoc/plugins-howto.html">How to Create Qt Plugins</a> for details.</p>
</div>
<p><b>See also </b><a href="qstylefactory.html">QStyleFactory</a> and <a href="qstyle.html">QStyle</a>.</p>
<!-- @@@QStylePlugin -->
<div class="func">
<h2>Member Function Documentation</h2>
<!-- $$$QStylePlugin[overload1]$$$QStylePluginQObject* -->
<h3 class="fn" id="QStylePlugin"><a name="QStylePlugin"></a>QStylePlugin::<span class="name">QStylePlugin</span>(<span class="type"><a href="../qtcore/qobject.html#QObject">QObject</a></span> *<i>parent</i> = nullptr)</h3>
<p>Constructs a style plugin with the given <i>parent</i>.</p>
<p>Note that this constructor is invoked automatically by the moc generated code that exports the plugin, so there is no need for calling it explicitly.</p>
<!-- @@@QStylePlugin -->
<!-- $$$~QStylePlugin[overload1]$$$~QStylePlugin -->
<h3 class="fn" id="dtor.QStylePlugin"><a name="dtor.QStylePlugin"></a><code>[virtual] </code>QStylePlugin::<span class="name">~QStylePlugin</span>()</h3>
<p>Destroys the style plugin.</p>
<p>Note that Qt destroys a plugin automatically when it is no longer used, so there is no need for calling the destructor explicitly.</p>
<!-- @@@~QStylePlugin -->
<!-- $$$create[overload1]$$$createconstQString& -->
<h3 class="fn" id="create"><a name="create"></a><code>[pure virtual] </code><span class="type"><a href="qstyle.html">QStyle</a></span> *QStylePlugin::<span class="name">create</span>(const <span class="type"><a href="../qtcore/qstring.html">QString</a></span> &amp;<i>key</i>)</h3>
<p>Creates and returns a <a href="qstyle.html">QStyle</a> object for the given style <i>key</i>. If a plugin cannot create a style, it should return 0 instead.</p>
<p>The style key is usually the class name of the required style. Note that the keys are case insensitive. For example:</p>
<pre class="cpp">

  <span class="type"><a href="qstyle.html">QStyle</a></span> <span class="operator">*</span>MyStylePlugin<span class="operator">::</span>create(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>key)
  {
      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> lcKey <span class="operator">=</span> key<span class="operator">.</span>toLower();
      <span class="keyword">if</span> (lcKey <span class="operator">=</span><span class="operator">=</span> <span class="string">&quot;rocket&quot;</span>) {
          <span class="keyword">return</span> <span class="keyword">new</span> RocketStyle;
      } <span class="keyword">else</span> <span class="keyword">if</span> (lcKey <span class="operator">=</span><span class="operator">=</span> <span class="string">&quot;starbuster&quot;</span>) {
          <span class="keyword">return</span> <span class="keyword">new</span> StarBusterStyle;
      }
      <span class="keyword">return</span> <span class="number">0</span>;
  }

</pre>
<!-- @@@create -->
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