The delegate provides a template defining each item instantiated by a view. The index is exposed as an accessibleindex property. Properties of the model are also available depending upon the type ofData Model.

This property holds the model providing data for theVisualDataModel.

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 aQAbstractItemModel subclass or a simple list.

Models can also be created directly in QML, using aListModel orXmlListModel.

See alsoData Models.

Theparts property selects aVisualDataModel which creates delegates from the part named. This is used in conjunction with thePackage element.

For example, the code below selects a model which creates delegates namedlist from aPackage:

VisualDataModel {    id: visualModel    delegate: Package {        Item { Package.name:"list" }    }    model: myModel}ListView {    width:200; height:200    model: visualModel.parts.list}

See alsoPackage.

QAbstractItemModel provides a hierarchical tree of data, whereas QML only operates on list data.rootIndex allows the children of any node in aQAbstractItemModel to be provided by this model.

This property only affects models of typeQAbstractItemModel that are hierarchical (e.g, a tree model).

For example, here is a simple interactive file system browser. When a directory name is clicked, the view'srootIndex is set to theQModelIndex node of the clicked directory, thus updating the view to show the new directory's contents.

main.cpp:

int main(int argc,char** argv){QApplication app(argc, argv);QDeclarativeView view;QDirModel model;    view.rootContext()->setContextProperty("dirModel",&model);    view.setSource(QUrl::fromLocalFile("view.qml"));    view.show();return app.exec();}

view.qml:

import QtQuick 1.0ListView {id:viewwidth:300height:400model:VisualDataModel {model:dirModeldelegate:Rectangle {width:200;height:25Text {text:filePath }MouseArea {anchors.fill:parentonClicked: {if (model.hasModelChildren)view.model.rootIndex=view.model.modelIndex(index)                }            }        }    }}

If themodel is aQAbstractItemModel subclass, the delegate can also reference ahasModelChildren property (optionally qualified by amodel. prefix) that indicates whether the delegate's model item has any child nodes.

See alsomodelIndex() andparentModelIndex().

QAbstractItemModel provides a hierarchical tree of data, whereas QML only operates on list data. This function assists in using tree models in QML.

Returns aQModelIndex for the specified index. This value can be assigned torootIndex.

See alsorootIndex.

QAbstractItemModel provides a hierarchical tree of data, whereas QML only operates on list data. This function assists in using tree models in QML.

Returns aQModelIndex for the parent of the currentrootIndex. This value can be assigned torootIndex.

See alsorootIndex.