QListWidget Class | Qt Widgets 6.1.1

- Qt 6.1
- Qt Widgets
- C++ Classes
- QListWidget
- Qt 6.1.1 Reference Documentation

# QListWidget Class

The QListWidget class provides an item-based list widget. More...

Header: | #include <QListWidget>
CMake: | find_package(Qt6 COMPONENTS Widgets REQUIRED) target_link_libraries(mytarget PRIVATE Qt6::Widgets)
qmake: | QT += widgets
Inherits: | QListView

- List of all members, including inherited members

## Properties

- count : const int
- currentRow : int
- sortingEnabled : bool

## Public Functions

| QListWidget(QWidget *parent = nullptr)
virtual | ~QListWidget()
void | addItem(const QString &label)
void | addItem(QListWidgetItem *item)
void | addItems(const QStringList &labels)
void | closePersistentEditor(QListWidgetItem *item)
int | count() const
QListWidgetItem * | currentItem() const
int | currentRow() const
void | editItem(QListWidgetItem *item)
QList<QListWidgetItem *> | findItems(const QString &text, Qt::MatchFlags flags) const
QModelIndex | indexFromItem(const QListWidgetItem *item) const
void | insertItem(int row, QListWidgetItem *item)
void | insertItem(int row, const QString &label)
void | insertItems(int row, const QStringList &labels)
bool | isPersistentEditorOpen(QListWidgetItem *item) const
bool | isSortingEnabled() const
QListWidgetItem * | item(int row) const
QListWidgetItem * | itemAt(const QPoint &p) const
QListWidgetItem * | itemAt(int x, int y) const
QListWidgetItem * | itemFromIndex(const QModelIndex &index) const
QWidget * | itemWidget(QListWidgetItem *item) const
QList<QListWidgetItem *> | items(const QMimeData *data) const
void | openPersistentEditor(QListWidgetItem *item)
void | removeItemWidget(QListWidgetItem *item)
int | row(const QListWidgetItem *item) const
QList<QListWidgetItem *> | selectedItems() const
void | setCurrentItem(QListWidgetItem *item)
void | setCurrentItem(QListWidgetItem *item, QItemSelectionModel::SelectionFlags command)
void | setCurrentRow(int row)
void | setCurrentRow(int row, QItemSelectionModel::SelectionFlags command)
void | setItemWidget(QListWidgetItem *item, QWidget *widget)
void | setSortingEnabled(bool enable)
void | sortItems(Qt::SortOrder order = Qt::AscendingOrder)
QListWidgetItem * | takeItem(int row)
QRect | visualItemRect(const QListWidgetItem *item) const

## Reimplemented Public Functions

virtual void | setSelectionModel(QItemSelectionModel *selectionModel) override

## Public Slots

void | clear()
void | scrollToItem(const QListWidgetItem *item, QAbstractItemView::ScrollHint hint = EnsureVisible)

## Signals

void | currentItemChanged(QListWidgetItem *current, QListWidgetItem *previous)
void | currentRowChanged(int currentRow)
void | currentTextChanged(const QString &currentText)
void | itemActivated(QListWidgetItem *item)
void | itemChanged(QListWidgetItem *item)
void | itemClicked(QListWidgetItem *item)
void | itemDoubleClicked(QListWidgetItem *item)
void | itemEntered(QListWidgetItem *item)
void | itemPressed(QListWidgetItem *item)
void | itemSelectionChanged()

## Protected Functions

virtual bool | dropMimeData(int index, const QMimeData *data, Qt::DropAction action)
virtual QMimeData * | mimeData(const QList<QListWidgetItem *> &items) const
virtual QStringList | mimeTypes() const
virtual Qt::DropActions | supportedDropActions() const

## Reimplemented Protected Functions

virtual void | dropEvent(QDropEvent *event) override
virtual bool | event(QEvent *e) override

## Detailed Description

QListWidget is a convenience class that provides a list view similar to the one supplied by QListView, but with a classic item-based interface for adding and removing items. QListWidget uses an internal model to manage each QListWidgetItem in the list.

For a more flexible list view widget, use the QListView class with a standard model.

List widgets are constructed in the same way as other widgets:

         QListWidget *listWidget = new QListWidget(this);

The selectionMode() of a list widget determines how many of the items in the list can be selected at the same time, and whether complex selections of items can be created. This can be set with the setSelectionMode() function.

There are two ways to add items to the list: they can be constructed with the list widget as their parent widget, or they can be constructed with no parent widget and added to the list later. If a list widget already exists when the items are constructed, the first method is easier to use:

         new QListWidgetItem(tr("Oak"), listWidget);
         new QListWidgetItem(tr("Fir"), listWidget);
         new QListWidgetItem(tr("Pine"), listWidget);

If you need to insert a new item into the list at a particular position, then it should be constructed without a parent widget. The insertItem() function should then be used to place it within the list. The list widget will take ownership of the item.

         QListWidgetItem *newItem = new QListWidgetItem;
         newItem->setText(itemText);
         listWidget->insertItem(row, newItem);

For multiple items, insertItems() can be used instead. The number of items in the list is found with the count() function. To remove items from the list, use takeItem().

The current item in the list can be found with currentItem(), and changed with setCurrentItem(). The user can also change the current item by navigating with the keyboard or clicking on a different item. When the current item changes, the currentItemChanged() signal is emitted with the new current item and the item that was previously current.

See also QListWidgetItem, QListView, QTreeView, Model/View Programming, and Tab Dialog Example.

## Property Documentation

### `[read-only]` count : const int

This property holds the number of items in the list including any hidden items.

Access functions:

int | count() const

### currentRow : int

This property holds the row of the current item.

Depending on the current selection mode, the row may also be selected.

Access functions:

int | currentRow() const
void | setCurrentRow(int row)
void | setCurrentRow(int row, QItemSelectionModel::SelectionFlags command)

Notifier signal:

void | currentRowChanged(int currentRow)

### sortingEnabled : bool

This property holds whether sorting is enabled

If this property is `true`, sorting is enabled for the list; if the property is false, sorting is not enabled.

The default value is false.

Access functions:

bool | isSortingEnabled() const
void | setSortingEnabled(bool enable)

## Member Function Documentation

### QListWidget::QListWidget(QWidget *parent = nullptr)

Constructs an empty QListWidget with the given parent.

### `[slot]` void QListWidget::clear()

Removes all items and selections in the view.

Warning: All items will be permanently deleted.

### `[signal]` void QListWidget::currentItemChanged(QListWidgetItem *current, QListWidgetItem *previous)

This signal is emitted whenever the current item changes.

previous is the item that previously had the focus; current is the new current item.

### `[signal]` void QListWidget::currentRowChanged(int currentRow)

This signal is emitted whenever the current item changes.

currentRow is the row of the current item. If there is no current item, the currentRow is -1.

Note: Notifier signal for property currentRow.

### `[signal]` void QListWidget::currentTextChanged(const QString &currentText)

This signal is emitted whenever the current item changes.

currentText is the text data in the current item. If there is no current item, the currentText is invalid.

### `[signal]` void QListWidget::itemActivated(QListWidgetItem *item)

This signal is emitted when the item is activated. The item is activated when the user clicks or double clicks on it, depending on the system configuration. It is also activated when the user presses the activation key (on Windows and X11 this is the Return key, on Mac OS X it is Command+O).

### `[signal]` void QListWidget::itemChanged(QListWidgetItem *item)

This signal is emitted whenever the data of item has changed.

### `[signal]` void QListWidget::itemClicked(QListWidgetItem *item)

This signal is emitted with the specified item when a mouse button is clicked on an item in the widget.

See also itemPressed() and itemDoubleClicked().

### `[signal]` void QListWidget::itemDoubleClicked(QListWidgetItem *item)

This signal is emitted with the specified item when a mouse button is double clicked on an item in the widget.

See also itemClicked() and itemPressed().

### `[signal]` void QListWidget::itemEntered(QListWidgetItem *item)

This signal is emitted when the mouse cursor enters an item. The item is the item entered. This signal is only emitted when mouseTracking is turned on, or when a mouse button is pressed while moving into an item.

See also QWidget::setMouseTracking().

### `[signal]` void QListWidget::itemPressed(QListWidgetItem *item)

This signal is emitted with the specified item when a mouse button is pressed on an item in the widget.

See also itemClicked() and itemDoubleClicked().

### `[signal]` void QListWidget::itemSelectionChanged()

This signal is emitted whenever the selection changes.

See also selectedItems(), QListWidgetItem::isSelected(), and currentItemChanged().

### `[slot]` void QListWidget::scrollToItem(const QListWidgetItem *item, QAbstractItemView::ScrollHint hint = EnsureVisible)

Scrolls the view if necessary to ensure that the item is visible.

hint specifies where the item should be located after the operation.

### `[virtual]` QListWidget::~QListWidget()

Destroys the list widget and all its items.

### void QListWidget::addItem(const QString &label)

Inserts an item with the text label at the end of the list widget.

### void QListWidget::addItem(QListWidgetItem *item)

Inserts the item at the end of the list widget.

Warning: A QListWidgetItem can only be added to a QListWidget once. Adding the same QListWidgetItem multiple times to a QListWidget will result in undefined behavior.

See also insertItem().

### void QListWidget::addItems(const QStringList &labels)

Inserts items with the text labels at the end of the list widget.

See also insertItems().

### void QListWidget::closePersistentEditor(QListWidgetItem *item)

Closes the persistent editor for the given item.

See also openPersistentEditor() and isPersistentEditorOpen().

### QListWidgetItem *QListWidget::currentItem() const

Returns the current item.

See also setCurrentItem().

### `[override virtual protected]` void QListWidget::dropEvent(QDropEvent *event)

Reimplements: QListView::dropEvent(QDropEvent *event).

### `[virtual protected]` bool QListWidget::dropMimeData(int index, const QMimeData *data, Qt::DropAction action)

Handles data supplied by an external drag and drop operation that ended with the given action in the given index. Returns `true` if data and action can be handled by the model; otherwise returns `false`.

See also supportedDropActions().

### void QListWidget::editItem(QListWidgetItem *item)

Starts editing the item if it is editable.

### `[override virtual protected]` bool QListWidget::event(QEvent *e)

Reimplements: QListView::event(QEvent *e).

### QList<QListWidgetItem *> QListWidget::findItems(const QString &text, Qt::MatchFlags flags) const

Finds items with the text that matches the string text using the given flags.

### QModelIndex QListWidget::indexFromItem(const QListWidgetItem *item) const

Returns the QModelIndex associated with the given item.

Note: In Qt versions prior to 5.10, this function took a non-`const` item.

### void QListWidget::insertItem(int row, QListWidgetItem *item)

Inserts the item at the position in the list given by row.

See also addItem().

### void QListWidget::insertItem(int row, const QString &label)

Inserts an item with the text label in the list widget at the position given by row.

See also addItem().

### void QListWidget::insertItems(int row, const QStringList &labels)

Inserts items from the list of labels into the list, starting at the given row.

See also insertItem() and addItem().

### `[since 5.10]` bool QListWidget::isPersistentEditorOpen(QListWidgetItem *item) const

Returns whether a persistent editor is open for item item.

This function was introduced in Qt 5.10.

See also openPersistentEditor() and closePersistentEditor().

### QListWidgetItem *QListWidget::item(int row) const

Returns the item that occupies the given row in the list if one has been set; otherwise returns `nullptr`.

See also row().

### QListWidgetItem *QListWidget::itemAt(const QPoint &p) const

Returns a pointer to the item at the coordinates p. The coordinates are relative to the list widget's viewport().

### QListWidgetItem *QListWidget::itemAt(int x, int y) const

This is an overloaded function.

Returns a pointer to the item at the coordinates (x, y). The coordinates are relative to the list widget's viewport().

### QListWidgetItem *QListWidget::itemFromIndex(const QModelIndex &index) const

Returns a pointer to the QListWidgetItem associated with the given index.

### QWidget *QListWidget::itemWidget(QListWidgetItem *item) const

Returns the widget displayed in the given item.

See also setItemWidget() and removeItemWidget().

### QList<QListWidgetItem *> QListWidget::items(const QMimeData *data) const

Returns a list of pointers to the items contained in the data object. If the object was not created by a QListWidget in the same process, the list is empty.

### `[virtual protected]` QMimeData *QListWidget::mimeData(const QList<QListWidgetItem *> &items) const

Returns an object that contains a serialized description of the specified items. The format used to describe the items is obtained from the mimeTypes() function.

If the list of items is empty, `nullptr` is returned instead of a serialized empty list.

### `[virtual protected]` QStringList QListWidget::mimeTypes() const

Returns a list of MIME types that can be used to describe a list of listwidget items.

See also mimeData().

### void QListWidget::openPersistentEditor(QListWidgetItem *item)

Opens an editor for the given item. The editor remains open after editing.

See also closePersistentEditor() and isPersistentEditorOpen().

### void QListWidget::removeItemWidget(QListWidgetItem *item)

Removes the widget set on the given item.

To remove an item (row) from the list entirely, either delete the item or use takeItem().

See also itemWidget() and setItemWidget().

### int QListWidget::row(const QListWidgetItem *item) const

Returns the row containing the given item.

See also item().

### QList<QListWidgetItem *> QListWidget::selectedItems() const

Returns a list of all selected items in the list widget.

### void QListWidget::setCurrentItem(QListWidgetItem *item)

Sets the current item to item.

Unless the selection mode is NoSelection, the item is also selected.

See also currentItem().

### void QListWidget::setCurrentItem(QListWidgetItem *item, QItemSelectionModel::SelectionFlags command)

Set the current item to item, using the given command.

### void QListWidget::setCurrentRow(int row, QItemSelectionModel::SelectionFlags command)

Sets the current row to be the given row, using the given command,

Note: Setter function for property currentRow.

### void QListWidget::setItemWidget(QListWidgetItem *item, QWidget *widget)

Sets the widget to be displayed in the given item.

This function should only be used to display static content in the place of a list widget item. If you want to display custom dynamic content or implement a custom editor widget, use QListView and subclass QStyledItemDelegate instead.

See also itemWidget(), removeItemWidget(), and Delegate Classes.

### `[override virtual]` void QListWidget::setSelectionModel(QItemSelectionModel *selectionModel)

Reimplements: QAbstractItemView::setSelectionModel(QItemSelectionModel *selectionModel).

### void QListWidget::sortItems(Qt::SortOrder order = Qt::AscendingOrder)

Sorts all the items in the list widget according to the specified order.

### `[virtual protected]` Qt::DropActions QListWidget::supportedDropActions() const

Returns the drop actions supported by this view.

See also Qt::DropActions.

### QListWidgetItem *QListWidget::takeItem(int row)

Removes and returns the item from the given row in the list widget; otherwise returns `nullptr`.

Items removed from a list widget will not be managed by Qt, and will need to be deleted manually.

See also insertItem() and addItem().

### QRect QListWidget::visualItemRect(const QListWidgetItem *item) const

Returns the rectangle on the viewport occupied by the item at item.