TreeView QML Type

Provides a tree view with scroll bars, styling and header sections. More...

Import Statement:	import QtQuick.Controls 1.4
Since:	Qt 5.5
Inherits:	ScrollView

List of all members, including inherited members

Properties

currentIndex : QModelIndex
itemDelegate : Component
model : QAbstractItemModel
rootIndex : QModelIndex
section
- section.property : string
- section.criteria : enumeration
- section.delegate : Component
- section.labelPositioning : enumeration
selection : ItemSelectionModel

Signals

activated(QModelIndex index)
clicked(QModelIndex index)
collapsed(QModelIndex index)
doubleClicked(QModelIndex index)
expanded(QModelIndex index)
pressAndHold(QModelIndex index)

Methods

void collapse(QModelIndex index)
void expand(QModelIndex index)
QModelIndex indexAt( int x, int y)
bool isExpanded(QModelIndex index)

Detailed Description

A TreeView implements a tree representation of items from a model.

Data for each row in the TreeView is provided by the model. TreeView accepts models derived from the QAbstractItemModel class.

You provide title and size of a column header by adding a TableViewColumn as demonstrated below.

TreeView {
    TableViewColumn {
        title: "Name"
        role: "fileName"
        width: 300
    }
    TableViewColumn {
        title: "Permissions"
        role: "filePermissions"
        width: 100
    }
    model: fileSystemModel
}

The header sections are attached to values in the model by defining the model role they attach to. Each property in the model will then be shown in their corresponding column.

You can customize the look by overriding the itemDelegate, rowDelegate, or headerDelegate properties.

The view itself does not provide sorting. This has to be done on the model itself. However you can provide sorting on the model, and enable sort indicators on headers.

int sortIndicatorColumn - The index of the current sort column
bool sortIndicatorVisible - Whether the sort indicator should be enabled
enum sortIndicatorOrder - Qt.AscendingOrder or Qt.DescendingOrder depending on state

You can create a custom appearance for a TreeView by assigning a TreeViewStyle.

Property Documentation

currentIndex : QModelIndex

The model index of the current row in the tree view.

itemDelegate : Component

This property defines a delegate to draw a specific cell.

In the item delegate you have access to the following special properties:

styleData.selected - if the item is currently selected
styleData.value - the value or text for this item
styleData.textColor - the default text color for an item
styleData.row - the index of the view row
styleData.column - the index of the view column
styleData.elideMode - the elide mode of the column
styleData.textAlignment - the horizontal text alignment of the column
styleData.pressed - true when the item is pressed
styleData.hasActiveFocus - true when the row has focus
styleData.index - the QModelIndex of the current item in the model
styleData.depth - the depth of the current item in the model
styleData.isExpanded - true when the item is expanded
styleData.hasChildren - true if the model index of the current item has or can have children
styleData.hasSibling - true if the model index of the current item has a sibling

Example:

itemDelegate: Item {
    Text {
        anchors.verticalCenter: parent.verticalCenter
        color: styleData.textColor
        elide: styleData.elideMode
        text: styleData.value
    }
}

Note: For performance reasons, created delegates can be recycled across multiple table rows. This implies that when you make use of implicit properties such as styleData.row or model, these values can change after the delegate has been constructed. This means that you should not assume that content is fixed when Component.onCompleted is called, but instead rely on bindings to such properties.

model : QAbstractItemModel

This property holds the model providing data for the tree view.

The model provides the set of data that is displayed by the view. The TreeView accept models derived from the QAbstractItemModel class.

rootIndex : QModelIndex

The model index of the root item in the tree view. The root item is the parent item to the view's top-level items. Only items descending from the root item will be visible in the view.

Its default value is an invalid QModelIndex, which means the whole model data is shown by the tree view (assigning undefined to this proprety resets it to its default value.)

This property was introduced in QtQuick.Controls 1.5.

section.property : string

These properties determine the section labels.

See also ListView.section.

selection : ItemSelectionModel

By default the selection model is null and only single selection is supported.

To use a different selection mode as described in selectionMode, an ItemSelectionModel must by set to the selection.

For example:

TreeView {
   model: myModel
   selection: ItemSelectionModel {
        model: myModel
   }
   TableViewColumn {
       role: "name"
       title: "Name
   }
}

See also selectionMode.

Signal Documentation

activated(QModelIndex index)

Emitted when the user activates a row in the tree by mouse or keyboard interaction. Mouse activation is triggered by single- or double-clicking, depending on the platform.

index is the model index of the activated row in the tree.

Note: This signal is only emitted for mouse interaction that is not blocked in the row or item delegate.

The corresponding handler is onActivated.