<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> <html><head><title>QExtensionFactory Class Reference</title><style>h3.fn,span.fn { margin-left: 1cm; text-indent: -1cm } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } td.postheader { font-family: sans-serif } tr.address { font-family: sans-serif } body { background: #ffffff; color: black; } </style></head><body><table border="0" cellpadding="0" cellspacing="0" width="100%"><tr /><td align="left" valign="top" width="32"><img align="left" border="0" height="32" src="images/rb-logo.png" width="32" /></td><td width="1">  </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a></td></table><h1 align="center">QExtensionFactory Class Reference<br /><sup><sup>[<a href="qtdesigner.html">QtDesigner</a> module]</sup></sup></h1><p>The QExtensionFactory class allows you to create a factory that is able to make instances of custom extensions in Qt Designer. <a href="#details">More...</a></p> <p>Inherits <a href="qobject.html">QObject</a> and <a href="qabstractextensionfactory.html">QAbstractExtensionFactory</a>.</p><h3>Methods</h3><ul><li><div class="fn" /><b><a href="qextensionfactory.html#QExtensionFactory">__init__</a></b> (<i>self</i>, QExtensionManager <i>parent</i> = None)</li><li><div class="fn" />QObject <b><a href="qextensionfactory.html#createExtension">createExtension</a></b> (<i>self</i>, QObject <i>object</i>, QString <i>iid</i>, QObject <i>parent</i>)</li><li><div class="fn" />QObject <b><a href="qextensionfactory.html#extension">extension</a></b> (<i>self</i>, QObject <i>object</i>, QString <i>iid</i>)</li><li><div class="fn" />QExtensionManager <b><a href="qextensionfactory.html#extensionManager">extensionManager</a></b> (<i>self</i>)</li></ul><a name="details" /><hr /><h2>Detailed Description</h2><p>The QExtensionFactory class allows you to create a factory that is able to make instances of custom extensions in Qt Designer.</p> <p>In <i>Qt Designer</i> the extensions are not created until they are required. For that reason, when implementing a custom extension, you must also create a QExtensionFactory, i.e. a class that is able to make an instance of your extension, and register it using <i>Qt Designer</i>'s <a href="qextensionmanager.html">extension manager</a>.</p> <p>The <a href="qextensionmanager.html">QExtensionManager</a> class provides extension management facilities for Qt Designer. When an extension is required, Qt Designer's <a href="qextensionmanager.html">extension manager</a> will run through all its registered factories calling <a href="qextensionfactory.html#createExtension">QExtensionFactory.createExtension</a>() for each until the first one that is able to create a requested extension for the selected object, is found. This factory will then make an instance of the extension.</p> <p>There are four available types of extensions in Qt Designer: <a href="qdesignercontainerextension.html">QDesignerContainerExtension</a> , <a href="qdesignermembersheetextension.html">QDesignerMemberSheetExtension</a>, <a href="qdesignerpropertysheetextension.html">QDesignerPropertySheetExtension</a> and <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a>. Qt Designer's behavior is the same whether the requested extension is associated with a multi page container, a member sheet, a property sheet or a task menu.</p> <p>You can either create a new QExtensionFactory and reimplement the <a href="qextensionfactory.html#createExtension">QExtensionFactory.createExtension</a>() function. For example:</p> <pre class="cpp"> <span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>ANewExtensionFactory<span class="operator">.</span><a href="qextensionfactory.html#createExtension">createExtension</a>(<span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>object<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>iid<span class="operator">,</span> <span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>parent) <span class="keyword">const</span> { <span class="keyword">if</span> (iid <span class="operator">!</span><span class="operator">=</span> Q_TYPEID(<span class="type"><a href="qdesignercontainerextension.html">QDesignerContainerExtension</a></span>)) <span class="keyword">return</span> <span class="number">0</span>; <span class="keyword">if</span> (MyCustomWidget <span class="operator">*</span>widget <span class="operator">=</span> qobject_cast<span class="operator"><</span>MyCustomWidget<span class="operator">*</span><span class="operator">></span> (object)) <span class="keyword">return</span> <span class="keyword">new</span> MyContainerExtension(widget<span class="operator">,</span> parent); <span class="keyword">return</span> <span class="number">0</span>; } </pre> <p>Or you can use an existing factory, expanding the <a href="qextensionfactory.html#createExtension">QExtensionFactory.createExtension</a>() function to make the factory able to create your extension as well. For example:</p> <pre class="cpp"> <span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>AGeneralExtensionFactory<span class="operator">.</span><a href="qextensionfactory.html#createExtension">createExtension</a>(<span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>object<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>iid<span class="operator">,</span> <span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>parent) <span class="keyword">const</span> { MyCustomWidget <span class="operator">*</span>widget <span class="operator">=</span> qobject_cast<span class="operator"><</span>MyCustomWidget<span class="operator">*</span><span class="operator">></span>(object); <span class="keyword">if</span> (widget <span class="operator">&</span><span class="operator">&</span> (iid <span class="operator">=</span><span class="operator">=</span> Q_TYPEID(<span class="type"><a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a></span>))) { <span class="keyword">return</span> <span class="keyword">new</span> MyTaskMenuExtension(widget<span class="operator">,</span> parent); } <span class="keyword">else</span> <span class="keyword">if</span> (widget <span class="operator">&</span><span class="operator">&</span> (iid <span class="operator">=</span><span class="operator">=</span> Q_TYPEID(<span class="type"><a href="qdesignercontainerextension.html">QDesignerContainerExtension</a></span>))) { <span class="keyword">return</span> <span class="keyword">new</span> MyContainerExtension(widget<span class="operator">,</span> parent); } <span class="keyword">else</span> { <span class="keyword">return</span> <span class="number">0</span>; } } </pre> <p>For a complete example using the QExtensionFactory class, see the <a href="designer-taskmenuextension.html">Task Menu Extension example</a>. The example shows how to create a custom widget plugin for Qt Designer, and how to to use the <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> class to add custom items to Qt Designer's task menu.</p> <hr /><h2>Method Documentation</h2><h3 class="fn"><a name="QExtensionFactory" />QExtensionFactory.__init__ (<i>self</i>, <a href="qextensionmanager.html">QExtensionManager</a> <i>parent</i> = None)</h3><p>The <i>parent</i> argument, if not None, causes <i>self</i> to be owned by Qt instead of PyQt.</p><p>Constructs an extension factory with the given <i>parent</i>.</p> <h3 class="fn"><a name="createExtension" /><a href="qobject.html">QObject</a> QExtensionFactory.createExtension (<i>self</i>, <a href="qobject.html">QObject</a> <i>object</i>, QString <i>iid</i>, <a href="qobject.html">QObject</a> <i>parent</i>)</h3><p>The <i>parent</i> argument, if not None, causes <i>self</i> to be owned by Qt instead of PyQt.</p><p>Creates an extension specified by <i>iid</i> for the given <i>object</i>. The extension object is created as a child of the specified <i>parent</i>.</p> <p><b>See also</b> <a href="qextensionfactory.html#extension">extension</a>().</p> <h3 class="fn"><a name="extension" /><a href="qobject.html">QObject</a> QExtensionFactory.extension (<i>self</i>, <a href="qobject.html">QObject</a> <i>object</i>, QString <i>iid</i>)</h3><p>Reimplemented from <a href="qabstractextensionfactory.html#extension">QAbstractExtensionFactory.extension</a>().</p> <p>Returns the extension specified by <i>iid</i> for the given <i>object</i>.</p> <p><b>See also</b> <a href="qextensionfactory.html#createExtension">createExtension</a>().</p> <h3 class="fn"><a name="extensionManager" /><a href="qextensionmanager.html">QExtensionManager</a> QExtensionFactory.extensionManager (<i>self</i>)</h3><p>Returns the extension manager for the extension factory.</p> <address><hr /><div align="center"><table border="0" cellspacing="0" width="100%"><tr class="address"><td align="left" width="25%">PyQt 4.10.3 for X11</td><td align="center" width="50%">Copyright © <a href="http://www.riverbankcomputing.com">Riverbank Computing Ltd</a> and <a href="http://www.qtsoftware.com">Nokia</a> 2012</td><td align="right" width="25%">Qt 4.8.5</td></tr></table></div></address></body></html>