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Breadcrumbs go here --> <li><a href="qdeclarativeelements.html">QML Elements</a></li> <li>QML VisualDataModel Element</li> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </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="#methods">Methods</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <h1 class="title">QML VisualDataModel Element</h1> <span class="subtitle"></span> <!-- $$$VisualDataModel-brief --> <p>The VisualDataModel encapsulates a model and delegate <a href="#details">More...</a></p> <!-- @@@VisualDataModel --> <ul> <li><a href="qml-visualdatamodel-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2>Properties</h2> <ul> <li class="fn"><b><b><a href="qml-visualdatamodel.html#delegate-prop">delegate</a></b></b> : Component</li> <li class="fn"><b><b><a href="qml-visualdatamodel.html#model-prop">model</a></b></b> : model</li> <li class="fn"><b><b><a href="qml-visualdatamodel.html#parts-prop">parts</a></b></b> : object</li> <li class="fn"><b><b><a href="qml-visualdatamodel.html#rootIndex-prop">rootIndex</a></b></b> : QModelIndex</li> </ul> <a name="methods"></a> <h2>Methods</h2> <ul> <li class="fn"><b><b><a href="qml-visualdatamodel.html#modelIndex-method">modelIndex</a></b></b></li> <li class="fn"><b><b><a href="qml-visualdatamodel.html#parentModelIndex-method">parentModelIndex</a></b></b></li> </ul> <!-- $$$VisualDataModel-description --> <a name="details"></a> <h2>Detailed Description</h2> <p>A VisualDataModel encapsulates a model and the delegate that will be instantiated for items in the model.</p> <p>It is usually not necessary to create VisualDataModel elements. However, it can be useful for manipulating and accessing the <a href="qml-visualdatamodel.html#modelIndex-method">modelIndex</a> when a <a href="qabstractitemmodel.html">QAbstractItemModel</a> subclass is used as the model. Also, VisualDataModel is used together with <a href="qml-package.html">Package</a> to provide delegates to multiple views.</p> <p>The example below illustrates using a VisualDataModel with a <a href="qml-listview.html">ListView</a>.</p> <pre class="qml"> import QtQuick 1.0 <span class="type"><a href="qml-rectangle.html">Rectangle</a></span> { <span class="name">width</span>: <span class="number">200</span>; <span class="name">height</span>: <span class="number">100</span> <span class="type">VisualDataModel</span> { <span class="name">id</span>: <span class="name">visualModel</span> <span class="name">model</span>: <span class="name">ListModel</span> { <span class="type"><a href="qml-listelement.html">ListElement</a></span> { <span class="name">name</span>: <span class="string">"Apple"</span> } <span class="type"><a href="qml-listelement.html">ListElement</a></span> { <span class="name">name</span>: <span class="string">"Orange"</span> } } <span class="name">delegate</span>: <span class="name">Rectangle</span> { <span class="name">height</span>: <span class="number">25</span> <span class="name">width</span>: <span class="number">100</span> <span class="type"><a href="qml-text.html">Text</a></span> { <span class="name">text</span>: <span class="string">"Name: "</span> <span class="operator">+</span> <span class="name">name</span>} } } <span class="type"><a href="qml-listview.html">ListView</a></span> { <span class="name">anchors</span>.fill: <span class="name">parent</span> <span class="name">model</span>: <span class="name">visualModel</span> } }</pre> <!-- @@@VisualDataModel --> <h2>Property Documentation</h2> <!-- $$$delegate --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="delegate-prop"></a><span class="name">delegate</span> : <span class="type"><a href="qml-component.html">Component</a></span></p></td></tr></table></div><div class="qmldoc"><p>The delegate provides a template defining each item instantiated by a view. The index is exposed as an accessible <tt>index</tt> property. Properties of the model are also available depending upon the type of <a href="qdeclarativemodels.html#qmlmodels">Data Model</a>.</p> </div></div><!-- @@@delegate --> <br/> <!-- $$$model --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="model-prop"></a><span class="name">model</span> : <span class="type">model</span></p></td></tr></table></div><div class="qmldoc"><p>This property holds the model providing data for the <a href="qml-visualdatamodel.html">VisualDataModel</a>.</p> <p>The model provides a set of data that is used to create the items for a view. For large or dynamic datasets the model is usually provided by a C++ model object. The C++ model object must be a <a href="qabstractitemmodel.html">QAbstractItemModel</a> subclass or a simple list.</p> <p>Models can also be created directly in QML, using a <a href="qml-listmodel.html">ListModel</a> or <a href="qml-xmllistmodel.html">XmlListModel</a>.</p> <p><b>See also </b><a href="qdeclarativemodels.html#qmlmodels">Data Models</a>.</p> </div></div><!-- @@@model --> <br/> <!-- $$$parts --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="parts-prop"></a><span class="qmlreadonly">read-only</span><span class="name">parts</span> : <span class="type">object</span></p></td></tr></table></div><div class="qmldoc"><p>The <i>parts</i> property selects a <a href="qml-visualdatamodel.html">VisualDataModel</a> which creates delegates from the part named. This is used in conjunction with the <a href="qml-package.html">Package</a> element.</p> <p>For example, the code below selects a model which creates delegates named <i>list</i> from a <a href="qml-package.html">Package</a>:</p> <pre class="cpp"> VisualDataModel { id: visualModel delegate: Package { Item { Package<span class="operator">.</span>name: <span class="string">"list"</span> } } model: myModel } ListView { width: <span class="number">200</span>; height:<span class="number">200</span> model: visualModel<span class="operator">.</span>parts<span class="operator">.</span>list }</pre> <p><b>See also </b><a href="qml-package.html">Package</a>.</p> </div></div><!-- @@@parts --> <br/> <!-- $$$rootIndex --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="rootIndex-prop"></a><span class="name">rootIndex</span> : <span class="type"><a href="qmodelindex.html">QModelIndex</a></span></p></td></tr></table></div><div class="qmldoc"><p><a href="qabstractitemmodel.html">QAbstractItemModel</a> provides a hierarchical tree of data, whereas QML only operates on list data. <tt>rootIndex</tt> allows the children of any node in a <a href="qabstractitemmodel.html">QAbstractItemModel</a> to be provided by this model.</p> <p>This property only affects models of type <a href="qabstractitemmodel.html">QAbstractItemModel</a> that are hierarchical (e.g, a tree model).</p> <p>For example, here is a simple interactive file system browser. When a directory name is clicked, the view's <tt>rootIndex</tt> is set to the <a href="qmodelindex.html">QModelIndex</a> node of the clicked directory, thus updating the view to show the new directory's contents.</p> <p><tt>main.cpp</tt>:</p> <pre class="cpp"> <span class="type">int</span> main(<span class="type">int</span> argc<span class="operator">,</span> <span class="type">char</span> <span class="operator">*</span><span class="operator">*</span> argv) { <span class="type"><a href="qapplication.html">QApplication</a></span> app(argc<span class="operator">,</span> argv); <span class="type"><a href="qdeclarativeview.html">QDeclarativeView</a></span> view; <span class="type"><a href="qdirmodel.html">QDirModel</a></span> model; view<span class="operator">.</span>rootContext()<span class="operator">-</span><span class="operator">></span>setContextProperty(<span class="string">"dirModel"</span><span class="operator">,</span> <span class="operator">&</span>model); view<span class="operator">.</span>setSource(<span class="type"><a href="qurl.html">QUrl</a></span><span class="operator">::</span>fromLocalFile(<span class="string">"view.qml"</span>)); view<span class="operator">.</span>show(); <span class="keyword">return</span> app<span class="operator">.</span>exec(); }</pre> <p><tt>view.qml</tt>:</p> <pre class="qml"> import QtQuick 1.0 <span class="type"><a href="qml-listview.html">ListView</a></span> { <span class="name">id</span>: <span class="name">view</span> <span class="name">width</span>: <span class="number">300</span> <span class="name">height</span>: <span class="number">400</span> <span class="name">model</span>: <span class="name">VisualDataModel</span> { <span class="name">model</span>: <span class="name">dirModel</span> <span class="name">delegate</span>: <span class="name">Rectangle</span> { <span class="name">width</span>: <span class="number">200</span>; <span class="name">height</span>: <span class="number">25</span> <span class="type"><a href="qml-text.html">Text</a></span> { <span class="name">text</span>: <span class="name">filePath</span> } <span class="type"><a href="qml-mousearea.html">MouseArea</a></span> { <span class="name">anchors</span>.fill: <span class="name">parent</span> <span class="name">onClicked</span>: { <span class="keyword">if</span> (<span class="name">model</span>.<span class="name">hasModelChildren</span>) <span class="name">view</span>.<span class="name">model</span>.<span class="name">rootIndex</span> <span class="operator">=</span> <span class="name">view</span>.<span class="name">model</span>.<span class="name">modelIndex</span>(<span class="name">index</span>) } } } } }</pre> <p>If the <a href="qml-visualdatamodel.html#model-prop">model</a> is a <a href="qabstractitemmodel.html">QAbstractItemModel</a> subclass, the delegate can also reference a <tt>hasModelChildren</tt> property (optionally qualified by a <i>model</i>. prefix) that indicates whether the delegate's model item has any child nodes.</p> <p><b>See also </b><a href="qml-visualdatamodel.html#modelIndex-method">modelIndex()</a> and <a href="qml-visualdatamodel.html#parentModelIndex-method">parentModelIndex()</a>.</p> </div></div><!-- @@@rootIndex --> <br/> <h2>Method Documentation</h2> <!-- $$$modelIndex --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlFuncNode"><p><a name="modelIndex-method"></a><span class="type"><a href="qmodelindex.html">QModelIndex</a></span> VisualDataModel::<span class="name">modelIndex</span> ( <span class="type"><a href="qml-int.html">int</a></span> <i>index</i> )</p></td></tr></table></div><div class="qmldoc"><p><a href="qabstractitemmodel.html">QAbstractItemModel</a> provides a hierarchical tree of data, whereas QML only operates on list data. This function assists in using tree models in QML.</p> <p>Returns a <a href="qmodelindex.html">QModelIndex</a> for the specified index. This value can be assigned to <a href="qml-visualdatamodel.html#rootIndex-prop">rootIndex</a>.</p> <p><b>See also </b><a href="qml-visualdatamodel.html#rootIndex-prop">rootIndex</a>.</p> </div></div><!-- @@@modelIndex --> <br/> <!-- $$$parentModelIndex --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlFuncNode"><p><a name="parentModelIndex-method"></a><span class="type"><a href="qmodelindex.html">QModelIndex</a></span> VisualDataModel::<span class="name">parentModelIndex</span> ()</p></td></tr></table></div><div class="qmldoc"><p><a href="qabstractitemmodel.html">QAbstractItemModel</a> provides a hierarchical tree of data, whereas QML only operates on list data. This function assists in using tree models in QML.</p> <p>Returns a <a href="qmodelindex.html">QModelIndex</a> for the parent of the current <a href="qml-visualdatamodel.html#rootIndex-prop">rootIndex</a>. This value can be assigned to <a href="qml-visualdatamodel.html#rootIndex-prop">rootIndex</a>.</p> <p><b>See also </b><a href="qml-visualdatamodel.html#rootIndex-prop">rootIndex</a>.</p> </div></div><!-- @@@parentModelIndex --> <br/> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2013 Digia Plc and/or its subsidiaries. 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