QComboBox Class

Member Function Documentation

QComboBox::QComboBox(QWidget *parent = nullptr)

Constructs a combobox with the given parent, using the default model QStandardItemModel.

[virtual] QComboBox::~QComboBox()

Destroys the combobox.

[signal] void QComboBox::activated(int index)

This signal is sent when the user chooses an item in the combobox. The item's index is passed. Note that this signal is sent even when the choice is not changed. If you need to know when the choice actually changes, use signal currentIndexChanged().

Note: Signal activated is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(comboBox, QOverload<int>::of(&QComboBox::activated),
    [=](int index){ /* ... */ });

[signal] void QComboBox::activated(const QString &text)

This signal is sent when the user chooses an item in the combobox. The item's text is passed. Note that this signal is sent even when the choice is not changed. If you need to know when the choice actually changes, use signal currentIndexChanged().

Note: Signal activated is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(comboBox, QOverload<const QString &>::of(&QComboBox::activated),
    [=](const QString &text){ /* ... */ });

void QComboBox::addItem(const QString &text, const QVariant &userData = QVariant())

Adds an item to the combobox with the given text, and containing the specified userData (stored in the Qt::UserRole). The item is appended to the list of existing items.

void QComboBox::addItem(const QIcon &icon, const QString &text, const QVariant &userData = QVariant())

Adds an item to the combobox with the given icon and text, and containing the specified userData (stored in the Qt::UserRole). The item is appended to the list of existing items.

void QComboBox::addItems(const QStringList &texts)

Adds each of the strings in the given texts to the combobox. Each item is appended to the list of existing items in turn.

[override virtual protected] void QComboBox::changeEvent(QEvent *e)

Reimplemented from QWidget::changeEvent().

[slot] void QComboBox::clear()

Clears the combobox, removing all items.

Note: If you have set an external model on the combobox this model will still be cleared when calling this function.

[slot] void QComboBox::clearEditText()

Clears the contents of the line edit used for editing in the combobox.

QCompleter *QComboBox::completer() const

Returns the completer that is used to auto complete text input for the combobox.

This function was introduced in Qt 4.2.

See also setCompleter() and editable.

[override virtual protected] void QComboBox::contextMenuEvent(QContextMenuEvent *e)

Reimplemented from QWidget::contextMenuEvent().

[signal] void QComboBox::currentIndexChanged(int index)

This signal is sent whenever the currentIndex in the combobox changes either through user interaction or programmatically. The item's index is passed or -1 if the combobox becomes empty or the currentIndex was reset.

Note: Signal currentIndexChanged is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(comboBox, QOverload<int>::of(&QComboBox::currentIndexChanged),
    [=](int index){ /* ... */ });

This function was introduced in Qt 4.1.

Note: Notifier signal for property currentIndex.

[signal] void QComboBox::currentIndexChanged(const QString &text)

This signal is sent whenever the currentIndex in the combobox changes either through user interaction or programmatically. The item's text is passed.

Note: Signal currentIndexChanged is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(comboBox, QOverload<const QString &>::of(&QComboBox::currentIndexChanged),
    [=](const QString &text){ /* ... */ });

This function was introduced in Qt 4.1.

Note: Notifier signal for property currentIndex.

[signal] void QComboBox::currentTextChanged(const QString &text)

This signal is sent whenever currentText changes. The new value is passed as text.

This function was introduced in Qt 5.0.

Note: Notifier signal for property currentText.

[signal] void QComboBox::editTextChanged(const QString &text)

This signal is emitted when the text in the combobox's line edit widget is changed. The new text is specified by text.

[override virtual] bool QComboBox::event(QEvent *event)

Reimplemented from QWidget::event().

int QComboBox::findData(const QVariant &data, int role, Qt::MatchFlags flags) const

Returns the index of the item containing the given data for the given role; otherwise returns -1.

The flags specify how the items in the combobox are searched.

int QComboBox::findText(const QString &text, Qt::MatchFlags flags) const

Returns the index of the item containing the given text; otherwise returns -1.

The flags specify how the items in the combobox are searched.

[override virtual protected] void QComboBox::focusInEvent(QFocusEvent *e)

Reimplemented from QWidget::focusInEvent().

[override virtual protected] void QComboBox::focusOutEvent(QFocusEvent *e)

Reimplemented from QWidget::focusOutEvent().

[override virtual protected] void QComboBox::hideEvent(QHideEvent *e)

Reimplemented from QWidget::hideEvent().

[virtual] void QComboBox::hidePopup()

Hides the list of items in the combobox if it is currently visible and resets the internal state, so that if the custom pop-up was shown inside the reimplemented showPopup(), then you also need to reimplement the hidePopup() function to hide your custom pop-up and call the base class implementation to reset the internal state whenever your custom pop-up widget is hidden.

See also showPopup().

[signal] void QComboBox::highlighted(int index)

This signal is sent when an item in the combobox popup list is highlighted by the user. The item's index is passed.

Note: Signal highlighted is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(comboBox, QOverload<int>::of(&QComboBox::highlighted),
    [=](int index){ /* ... */ });

[signal] void QComboBox::highlighted(const QString &text)

This signal is sent when an item in the combobox popup list is highlighted by the user. The item's text is passed.

Note: Signal highlighted is overloaded in this class. To connect to this signal by using the function pointer syntax, Qt provides a convenient helper for obtaining the function pointer as shown in this example:

connect(comboBox, QOverload<const QString &>::of(&QComboBox::highlighted),
    [=](const QString &text){ /* ... */ });

[protected] void QComboBox::initStyleOption(QStyleOptionComboBox *option) const

Initialize option with the values from this QComboBox. This method is useful for subclasses when they need a QStyleOptionComboBox, but don't want to fill in all the information themselves.

See also QStyleOption::initFrom().

[override virtual protected] void QComboBox::inputMethodEvent(QInputMethodEvent *e)

Reimplemented from QWidget::inputMethodEvent().

[override virtual] QVariant QComboBox::inputMethodQuery(Qt::InputMethodQuery query) const

Reimplemented from QWidget::inputMethodQuery().

void QComboBox::insertItem(int index, const QString &text, const QVariant &userData = QVariant())

Inserts the text and userData (stored in the Qt::UserRole) into the combobox at the given index.

If the index is equal to or higher than the total number of items, the new item is appended to the list of existing items. If the index is zero or negative, the new item is prepended to the list of existing items.

See also insertItems().

void QComboBox::insertItem(int index, const QIcon &icon, const QString &text, const QVariant &userData = QVariant())

Inserts the icon, text and userData (stored in the Qt::UserRole) into the combobox at the given index.

If the index is equal to or higher than the total number of items, the new item is appended to the list of existing items. If the index is zero or negative, the new item is prepended to the list of existing items.

See also insertItems().

void QComboBox::insertItems(int index, const QStringList &list)

Inserts the strings from the list into the combobox as separate items, starting at the index specified.

If the index is equal to or higher than the total number of items, the new items are appended to the list of existing items. If the index is zero or negative, the new items are prepended to the list of existing items.

See also insertItem().

void QComboBox::insertSeparator(int index)

Inserts a separator item into the combobox at the given index.

If the index is equal to or higher than the total number of items, the new item is appended to the list of existing items. If the index is zero or negative, the new item is prepended to the list of existing items.

This function was introduced in Qt 4.4.

See also insertItem().

QVariant QComboBox::itemData(int index, int role = Qt::UserRole) const

Returns the data for the given role in the given index in the combobox, or QVariant::Invalid if there is no data for this role.

See also setItemData().

QAbstractItemDelegate *QComboBox::itemDelegate() const

Returns the item delegate used by the popup list view.

See also setItemDelegate().

QIcon QComboBox::itemIcon(int index) const

Returns the icon for the given index in the combobox.

See also setItemIcon().

QString QComboBox::itemText(int index) const

Returns the text for the given index in the combobox.

See also setItemText().

[override virtual protected] void QComboBox::keyPressEvent(QKeyEvent *e)

Reimplemented from QWidget::keyPressEvent().

[override virtual protected] void QComboBox::keyReleaseEvent(QKeyEvent *e)

Reimplemented from QWidget::keyReleaseEvent().

QLineEdit *QComboBox::lineEdit() const

Returns the line edit used to edit items in the combobox, or 0 if there is no line edit.

Only editable combo boxes have a line edit.

See also setLineEdit().

[override virtual] QSize QComboBox::minimumSizeHint() const

Reimplemented from QWidget::minimumSizeHint().

QAbstractItemModel *QComboBox::model() const

Returns the model used by the combobox.

See also setModel().

[override virtual protected] void QComboBox::mousePressEvent(QMouseEvent *e)

Reimplemented from QWidget::mousePressEvent().

[override virtual protected] void QComboBox::mouseReleaseEvent(QMouseEvent *e)

Reimplemented from QWidget::mouseReleaseEvent().

[override virtual protected] void QComboBox::paintEvent(QPaintEvent *e)

Reimplemented from QWidget::paintEvent().

void QComboBox::removeItem(int index)

Removes the item at the given index from the combobox. This will update the current index if the index is removed.

This function does nothing if index is out of range.

[override virtual protected] void QComboBox::resizeEvent(QResizeEvent *e)

Reimplemented from QWidget::resizeEvent().

QModelIndex QComboBox::rootModelIndex() const

Returns the root model item index for the items in the combobox.

See also setRootModelIndex().

void QComboBox::setCompleter(QCompleter *completer)

Sets the completer to use instead of the current completer. If completer is 0, auto completion is disabled.

By default, for an editable combo box, a QCompleter that performs case insensitive inline completion is automatically created.

Note: The completer is removed when the editable property becomes false.

This function was introduced in Qt 4.2.

See also completer().

[slot] void QComboBox::setEditText(const QString &text)

Sets the text in the combobox's text edit.

void QComboBox::setItemData(int index, const QVariant &value, int role = Qt::UserRole)

Sets the data role for the item on the given index in the combobox to the specified value.

See also itemData().

void QComboBox::setItemDelegate(QAbstractItemDelegate *delegate)

Sets the item delegate for the popup list view. The combobox takes ownership of the delegate.

Warning: You should not share the same instance of a delegate between comboboxes, widget mappers or views. Doing so can cause incorrect or unintuitive editing behavior since each view connected to a given delegate may receive the closeEditor() signal, and attempt to access, modify or close an editor that has already been closed.

See also itemDelegate().

void QComboBox::setItemIcon(int index, const QIcon &icon)

Sets the icon for the item on the given index in the combobox.

See also itemIcon().

void QComboBox::setItemText(int index, const QString &text)

Sets the text for the item on the given index in the combobox.

See also itemText().

void QComboBox::setLineEdit(QLineEdit *edit)

Sets the line edit to use instead of the current line edit widget.

The combo box takes ownership of the line edit.

See also lineEdit().

void QComboBox::setModel(QAbstractItemModel *model)

Sets the model to be model. model must not be 0. If you want to clear the contents of a model, call clear().

See also model() and clear().

void QComboBox::setRootModelIndex(const QModelIndex &index)

Sets the root model item index for the items in the combobox.

See also rootModelIndex().

void QComboBox::setValidator(const QValidator *validator)

Sets the validator to use instead of the current validator.

Note: The validator is removed when the editable property becomes false.

See also validator().

void QComboBox::setView(QAbstractItemView *itemView)

Sets the view to be used in the combobox popup to the given itemView. The combobox takes ownership of the view.

Note: If you want to use the convenience views (like QListWidget, QTableWidget or QTreeWidget), make sure to call setModel() on the combobox with the convenience widgets model before calling this function.

See also view().

[override virtual protected] void QComboBox::showEvent(QShowEvent *e)

Reimplemented from QWidget::showEvent().

[virtual] void QComboBox::showPopup()

Displays the list of items in the combobox. If the list is empty then the no items will be shown.

If you reimplement this function to show a custom pop-up, make sure you call hidePopup() to reset the internal state.

See also hidePopup().

[override virtual] QSize QComboBox::sizeHint() const

Reimplemented from QWidget::sizeHint().

This implementation caches the size hint to avoid resizing when the contents change dynamically. To invalidate the cached value change the sizeAdjustPolicy.

const QValidator *QComboBox::validator() const

Returns the validator that is used to constrain text input for the combobox.

See also setValidator() and editable.

QAbstractItemView *QComboBox::view() const

Returns the list view used for the combobox popup.

See also setView().

[override virtual protected] void QComboBox::wheelEvent(QWheelEvent *e)

Reimplemented from QWidget::wheelEvent().