QItemSelectionModel Class

The QItemSelectionModel class keeps track of a view's selected items. More...

Header:	#include <QItemSelectionModel>
qmake:	QT += core
Inherits:	QObject

• List of all members, including inherited members

Public Types

enum	SelectionFlag { NoUpdate, Clear, Select, Deselect, Toggle, …, ClearAndSelect }
flags	SelectionFlags

Properties

• selectedIndexes : const QModelIndexList

Public Functions

	QItemSelectionModel(QAbstractItemModel *model, QObject *parent)
	QItemSelectionModel(QAbstractItemModel *model = nullptr)
virtual	~QItemSelectionModel()
bool	columnIntersectsSelection(int column, const QModelIndex &parent = QModelIndex()) const
QModelIndex	currentIndex() const
bool	hasSelection() const
bool	isColumnSelected(int column, const QModelIndex &parent = QModelIndex()) const
bool	isRowSelected(int row, const QModelIndex &parent = QModelIndex()) const
bool	isSelected(const QModelIndex &index) const
const QAbstractItemModel *	model() const
QAbstractItemModel *	model()
bool	rowIntersectsSelection(int row, const QModelIndex &parent = QModelIndex()) const
QModelIndexList	selectedColumns(int row = 0) const
QModelIndexList	selectedIndexes() const
QModelIndexList	selectedRows(int column = 0) const
const QItemSelection	selection() const
void	setModel(QAbstractItemModel *model)

Public Slots

virtual void	clear()
virtual void	clearCurrentIndex()
void	clearSelection()
virtual void	reset()
virtual void	select(const QItemSelection &selection, QItemSelectionModel::SelectionFlags command)
virtual void	select(const QModelIndex &index, QItemSelectionModel::SelectionFlags command)
virtual void	setCurrentIndex(const QModelIndex &index, QItemSelectionModel::SelectionFlags command)

Signals

void	currentChanged(const QModelIndex &current, const QModelIndex &previous)
void	currentColumnChanged(const QModelIndex &current, const QModelIndex &previous)
void	currentRowChanged(const QModelIndex &current, const QModelIndex &previous)
void	modelChanged(QAbstractItemModel *model)
void	selectionChanged(const QItemSelection &selected, const QItemSelection &deselected)

Protected Functions

void	emitSelectionChanged(const QItemSelection &newSelection, const QItemSelection &oldSelection)

Detailed Description

A QItemSelectionModel keeps track of the selected items in a view, or in several views onto the same model. It also keeps track of the currently selected item in a view.

The QItemSelectionModel class is one of the Model/View Classes and is part of Qt's model/view framework.

The selected items are stored using ranges. Whenever you want to modify the selected items use select() and provide either a QItemSelection, or a QModelIndex and a QItemSelectionModel::SelectionFlag.

The QItemSelectionModel takes a two layer approach to selection management, dealing with both selected items that have been committed and items that are part of the current selection. The current selected items are part of the current interactive selection (for example with rubber-band selection or keyboard-shift selections).

To update the currently selected items, use the bitwise OR of QItemSelectionModel::Current and any of the other SelectionFlags. If you omit the QItemSelectionModel::Current command, a new current selection will be created, and the previous one added to the whole selection. All functions operate on both layers; for example, selecteditems() will return items from both layers.

Note: Since 5.5, model, hasSelection, and currentIndex are meta-object properties.

See also Model/View Programming, QAbstractItemModel, and Chart Example.

Member Type Documentation

enum QItemSelectionModel::SelectionFlagflags QItemSelectionModel::SelectionFlags

This enum describes the way the selection model will be updated.

Constant	Value	Description
QItemSelectionModel::NoUpdate	0x0000	No selection will be made.
QItemSelectionModel::Clear	0x0001	The complete selection will be cleared.
QItemSelectionModel::Select	0x0002	All specified indexes will be selected.
QItemSelectionModel::Deselect	0x0004	All specified indexes will be deselected.
QItemSelectionModel::Toggle	0x0008	All specified indexes will be selected or deselected depending on their current state.
QItemSelectionModel::Current	0x0010	The current selection will be updated.
QItemSelectionModel::Rows	0x0020	All indexes will be expanded to span rows.
QItemSelectionModel::Columns	0x0040	All indexes will be expanded to span columns.
QItemSelectionModel::SelectCurrent	Select | Current	A combination of Select and Current, provided for convenience.
QItemSelectionModel::ToggleCurrent	Toggle | Current	A combination of Toggle and Current, provided for convenience.
QItemSelectionModel::ClearAndSelect	Clear | Select	A combination of Clear and Select, provided for convenience.

The SelectionFlags type is a typedef for QFlags<SelectionFlag>. It stores an OR combination of SelectionFlag values.

Member Function Documentation

QItemSelectionModel::QItemSelectionModel(QAbstractItemModel *model, QObject *parent)

Constructs a selection model that operates on the specified item model with parent.

QItemSelectionModel::QItemSelectionModel(QAbstractItemModel *model = nullptr)

Constructs a selection model that operates on the specified item model.

[virtual slot] void QItemSelectionModel::clear()

Clears the selection model. Emits selectionChanged() and currentChanged().

[virtual slot] void QItemSelectionModel::clearCurrentIndex()

Clears the current index. Emits currentChanged().

[slot] void QItemSelectionModel::clearSelection()

Clears the selection in the selection model. Emits selectionChanged().

This function was introduced in Qt 4.2.

[signal] void QItemSelectionModel::currentChanged(const QModelIndex &current, const QModelIndex &previous)

This signal is emitted whenever the current item changes. The previous model item index is replaced by the current index as the selection's current item.

Note that this signal will not be emitted when the item model is reset.

See also currentIndex(), setCurrentIndex(), and selectionChanged().

[signal] void QItemSelectionModel::currentColumnChanged(const QModelIndex &current, const QModelIndex &previous)

This signal is emitted if the current item changes and its column is different to the column of the previous current item.

Note that this signal will not be emitted when the item model is reset.

See also currentChanged(), currentRowChanged(), currentIndex(), and setCurrentIndex().

[signal] void QItemSelectionModel::currentRowChanged(const QModelIndex &current, const QModelIndex &previous)

This signal is emitted if the current item changes and its row is different to the row of the previous current item.

Note that this signal will not be emitted when the item model is reset.

See also currentChanged(), currentColumnChanged(), currentIndex(), and setCurrentIndex().

[signal] void QItemSelectionModel::modelChanged(QAbstractItemModel *model)

This signal is emitted when the model is successfully set with setModel().

This function was introduced in Qt 5.5.

See also model() and setModel().

[virtual slot] void QItemSelectionModel::reset()

Clears the selection model. Does not emit any signals.

[virtual slot] void QItemSelectionModel::select(const QItemSelection &selection, QItemSelectionModel::SelectionFlags command)

Selects the item selection using the specified command, and emits selectionChanged().

See also QItemSelectionModel::SelectionFlag.

[virtual slot] void QItemSelectionModel::select(const QModelIndex &index, QItemSelectionModel::SelectionFlags command)

Selects the model item index using the specified command, and emits selectionChanged().

See also QItemSelectionModel::SelectionFlags.

[signal] void QItemSelectionModel::selectionChanged(const QItemSelection &selected, const QItemSelection &deselected)

This signal is emitted whenever the selection changes. The change in the selection is represented as an item selection of deselected items and an item selection of selected items.

Note the that the current index changes independently from the selection. Also note that this signal will not be emitted when the item model is reset.

Note: Notifier signal for property selectedIndexes.

See also select() and currentChanged().

[virtual slot] void QItemSelectionModel::setCurrentIndex(const QModelIndex &index, QItemSelectionModel::SelectionFlags command)

Sets the model item index to be the current item, and emits currentChanged(). The current item is used for keyboard navigation and focus indication; it is independent of any selected items, although a selected item can also be the current item.

Depending on the specified command, the index can also become part of the current selection.

See also currentIndex() and select().

[virtual] QItemSelectionModel::~QItemSelectionModel()

Destroys the selection model.

bool QItemSelectionModel::columnIntersectsSelection(int column, const QModelIndex &parent = QModelIndex()) const

Returns true if there are any items selected in the column with the given parent.

Note: Since Qt 5.15, the default argument for parent is an empty model index.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

QModelIndex QItemSelectionModel::currentIndex() const

Returns the model item index for the current item, or an invalid index if there is no current item.

See also setCurrentIndex().

[protected] void QItemSelectionModel::emitSelectionChanged(const QItemSelection &newSelection, const QItemSelection &oldSelection)

Compares the two selections newSelection and oldSelection and emits selectionChanged() with the deselected and selected items.

bool QItemSelectionModel::hasSelection() const

Returns true if the selection model contains any selection ranges; otherwise returns false.

This function was introduced in Qt 4.2.

bool QItemSelectionModel::isColumnSelected(int column, const QModelIndex &parent = QModelIndex()) const

Returns true if all items are selected in the column with the given parent.

Note that this function is usually faster than calling isSelected() on all items in the same column and that unselectable items are ignored.

Note: Since Qt 5.15, the default argument for parent is an empty model index.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

bool QItemSelectionModel::isRowSelected(int row, const QModelIndex &parent = QModelIndex()) const

Returns true if all items are selected in the row with the given parent.

Note that this function is usually faster than calling isSelected() on all items in the same row and that unselectable items are ignored.

Note: Since Qt 5.15, the default argument for parent is an empty model index.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

bool QItemSelectionModel::isSelected(const QModelIndex &index) const

Returns true if the given model item index is selected.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

const QAbstractItemModel *QItemSelectionModel::model() const

Returns the item model operated on by the selection model.

See also setModel().

QAbstractItemModel *QItemSelectionModel::model()

Returns the item model operated on by the selection model.

This function was introduced in Qt 5.5.

bool QItemSelectionModel::rowIntersectsSelection(int row, const QModelIndex &parent = QModelIndex()) const

Returns true if there are any items selected in the row with the given parent.

Note: Since Qt 5.15, the default argument for parent is an empty model index.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

QModelIndexList QItemSelectionModel::selectedColumns(int row = 0) const

Returns the indexes in the given row for columns where all rows are selected.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

This function was introduced in Qt 4.2.

See also selectedIndexes() and selectedRows().

QModelIndexList QItemSelectionModel::selectedIndexes() const

Returns a list of all selected model item indexes. The list contains no duplicates, and is not sorted.

Note: Getter function for property selectedIndexes.

QModelIndexList QItemSelectionModel::selectedRows(int column = 0) const

Returns the indexes in the given column for the rows where all columns are selected.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

This function was introduced in Qt 4.2.

See also selectedIndexes() and selectedColumns().

const QItemSelection QItemSelectionModel::selection() const

Returns the selection ranges stored in the selection model.

void QItemSelectionModel::setModel(QAbstractItemModel *model)

Sets the model to model. The modelChanged() signal will be emitted.

This function was introduced in Qt 5.5.

See also model() and modelChanged().