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<td >Qt 5.9</td><td ><a href="qtdesigner-manual.html">Qt Designer Manual</a></td><td ><a href="qtdesigner-module.html">C++ Classes</a></td><td >QDesignerTaskMenuExtension</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td>
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<h3><a name="toc">Contents</a></h3>
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<li class="level1"><a href="#public-functions">Public Functions</a></li>
<li class="level1"><a href="#details">Detailed Description</a></li>
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<h1 class="title">QDesignerTaskMenuExtension Class</h1>
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<p>The <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> class allows you to add custom menu entries to Qt Designer's task menu. <a href="#details">More...</a></p>
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<tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QDesignerTaskMenuExtension></span>
</td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += designer</td></tr></table></div><ul>
<li><a href="qdesignertaskmenuextension-members.html">List of all members, including inherited members</a></li>
</ul>
<a name="public-functions"></a>
<h2 id="public-functions">Public Functions</h2>
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<tr><td class="memItemLeft rightAlign topAlign"> virtual </td><td class="memItemRight bottomAlign"><b><a href="qdesignertaskmenuextension.html#dtor.QDesignerTaskMenuExtension">~QDesignerTaskMenuExtension</a></b>()</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual QAction *</td><td class="memItemRight bottomAlign"><b><a href="qdesignertaskmenuextension.html#preferredEditAction">preferredEditAction</a></b>() const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> virtual QList<QAction *> </td><td class="memItemRight bottomAlign"><b><a href="qdesignertaskmenuextension.html#taskActions">taskActions</a></b>() const = 0</td></tr>
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<a name="details"></a>
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<div class="descr">
<h2 id="details">Detailed Description</h2>
<p>The <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> class allows you to add custom menu entries to Qt Designer's task menu.</p>
<p><a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> provides an interface for creating custom task menu extensions. It is typically used to create task menu entries that are specific to a plugin in <i>Qt Designer</i>.</p>
<p><i>Qt Designer</i> uses the <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> to feed its task menu. Whenever a task menu is requested, <i>Qt Designer</i> will query for the selected widget's task menu extension.</p>
<p class="centerAlign"><img src="images/taskmenuextension-example-faded.png" alt="" /></p><p>A task menu extension is a collection of QActions. The actions appear as entries in the task menu when the plugin with the specified extension is selected. The image above shows the custom <b>Edit State...</b> action which appears in addition to <i>Qt Designer</i>'s default task menu entries: <b>Cut</b>, <b>Copy</b>, <b>Paste</b> etc.</p>
<p>To create a custom task menu extension, your extension class must inherit from both QObject and <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a>. For example:</p>
<pre class="cpp">
<span class="keyword">class</span> MyTaskMenuExtension : <span class="keyword">public</span> <span class="type">QObject</span><span class="operator">,</span>
<span class="keyword">public</span> <span class="type"><a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a></span>
{
Q_OBJECT
Q_INTERFACES(<span class="type"><a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a></span>)
<span class="keyword">public</span>:
MyTaskMenuExtension(MyCustomWidget <span class="operator">*</span>widget<span class="operator">,</span> <span class="type">QObject</span> <span class="operator">*</span>parent);
<span class="type">QAction</span> <span class="operator">*</span>preferredEditAction() <span class="keyword">const</span>;
<span class="type">QList</span><span class="operator"><</span><span class="type">QAction</span> <span class="operator">*</span><span class="operator">></span> taskActions() <span class="keyword">const</span>;
<span class="keyword">private</span> <span class="keyword">slots</span>:
<span class="type">void</span> mySlot();
<span class="keyword">private</span>:
MyCustomWidget <span class="operator">*</span>widget;
<span class="type">QAction</span> <span class="operator">*</span>myAction;
};
</pre>
<p>Since we are implementing an interface, we must ensure that it is made known to the meta-object system using the Q_INTERFACES() macro. This enables <i>Qt Designer</i> to use the qobject_cast() function to query for supported interfaces using nothing but a QObject pointer.</p>
<p>You must reimplement the <a href="qdesignertaskmenuextension.html#taskActions">taskActions</a>() function to return a list of actions that will be included in <i>Qt Designer</i> task menu. Optionally, you can reimplement the <a href="qdesignertaskmenuextension.html#preferredEditAction">preferredEditAction</a>() function to set the action that is invoked when selecting your plugin and pressing <b>F2</b>. The preferred edit action must be one of the actions returned by <a href="qdesignertaskmenuextension.html#taskActions">taskActions</a>() and, if it's not defined, pressing the <b>F2</b> key will simply be ignored.</p>
<p>In <i>Qt Designer</i>, extensions are not created until they are required. A task menu extension, for example, is created when you click the right mouse button over a widget in <i>Qt Designer</i>'s workspace. For that reason you must also construct an extension factory, using either <a href="qextensionfactory.html">QExtensionFactory</a> or a subclass, and register it using <i>Qt Designer</i>'s <a href="qextensionmanager.html">extension manager</a>.</p>
<p>When a task menu extension is required, <i>Qt Designer</i>'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 it finds one that is able to create a task menu extension for the selected widget. This factory will then make an instance of the extension.</p>
<p>There are four available types of extensions in <i>Qt Designer</i>: <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>. <i>Qt Designer</i>'s behavior is the same whether the requested extension is associated with a container, a member sheet, a property sheet or a task menu.</p>
<p>The <a href="qextensionfactory.html">QExtensionFactory</a> class provides a standard extension factory, and can also be used as an interface for custom extension factories. You can either create a new <a href="qextensionfactory.html">QExtensionFactory</a> and reimplement the <a href="qextensionfactory.html#createExtension">QExtensionFactory::createExtension</a>() function. For example:</p>
<pre class="cpp">
<span class="type">QObject</span> <span class="operator">*</span>ANewExtensionFactory<span class="operator">::</span>createExtension(<span class="type">QObject</span> <span class="operator">*</span>object<span class="operator">,</span>
<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>iid<span class="operator">,</span> <span class="type">QObject</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="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</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> MyTaskMenuExtension(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 a task menu extension as well. For example:</p>
<pre class="cpp">
<span class="type">QObject</span> <span class="operator">*</span>AGeneralExtensionFactory<span class="operator">::</span>createExtension(<span class="type">QObject</span> <span class="operator">*</span>object<span class="operator">,</span>
<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>iid<span class="operator">,</span> <span class="type">QObject</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="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">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">return</span> <span class="number">0</span>;
}
}
</pre>
<p>For a complete example using the <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> class, see the <a href="qtdesigner-taskmenuextension-example.html">Task Menu Extension example</a>. The example shows how to create a custom widget plugin for <i>Qt Designer</i>, and how to to use the <a href="qdesignertaskmenuextension.html">QDesignerTaskMenuExtension</a> class to add custom items to <i>Qt Designer</i>'s task menu.</p>
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<p><b>See also </b><a href="qextensionfactory.html">QExtensionFactory</a>, <a href="qextensionmanager.html">QExtensionManager</a>, and <a href="designer-creating-custom-widgets-extensions.html">Creating Custom Widget Extensions</a>.</p>
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<h2>Member Function Documentation</h2>
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<h3 class="fn" id="dtor.QDesignerTaskMenuExtension"><a name="dtor.QDesignerTaskMenuExtension"></a><code>[virtual] </code>QDesignerTaskMenuExtension::<span class="name">~QDesignerTaskMenuExtension</span>()</h3>
<p>Destroys the task menu extension.</p>
<!-- @@@~QDesignerTaskMenuExtension -->
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<h3 class="fn" id="preferredEditAction"><a name="preferredEditAction"></a><code>[virtual] </code><span class="type">QAction</span> *QDesignerTaskMenuExtension::<span class="name">preferredEditAction</span>() const</h3>
<p>Returns the action that is invoked when selecting a plugin with the specified extension and pressing <b>F2</b>.</p>
<p>The action must be one of the actions returned by <a href="qdesignertaskmenuextension.html#taskActions">taskActions</a>().</p>
<!-- @@@preferredEditAction -->
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<h3 class="fn" id="taskActions"><a name="taskActions"></a><code>[pure virtual] </code><span class="type">QList</span><<span class="type">QAction</span> *> QDesignerTaskMenuExtension::<span class="name">taskActions</span>() const</h3>
<p>Returns the task menu extension as a list of actions which will be included in <i>Qt Designer</i>'s task menu when a plugin with the specified extension is selected.</p>
<p>The function must be reimplemented to add actions to the list.</p>
<!-- @@@taskActions -->
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