The QStyledItemDelegate class provides display and editing facilities for data items from a model. More...

#include <qstyleditemdelegate.h>

Inheritance diagram for QStyledItemDelegate:

Collaboration diagram for QStyledItemDelegate:

Public Member Functions
	QStyledItemDelegate (QObject *parent=nullptr)
	Constructs an item delegate with the given parent.

	~QStyledItemDelegate ()
	Destroys the item delegate.

void	paint (QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const override
	Renders the delegate using the given painter and style option for the item specified by index.

QSize	sizeHint (const QStyleOptionViewItem &option, const QModelIndex &index) const override
	Returns the size needed by the delegate to display the item specified by index, taking into account the style information provided by option.

QWidget *	createEditor (QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const override
	Returns the widget used to edit the item specified by index for editing.

void	setEditorData (QWidget *editor, const QModelIndex &index) const override
	Sets the data to be displayed and edited by the editor from the data model item specified by the model index.

void	setModelData (QWidget editor, QAbstractItemModel model, const QModelIndex &index) const override
	Gets data from the editor widget and stores it in the specified model at the item index.

void	updateEditorGeometry (QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const override
	Updates the editor for the item specified by index according to the style option given.

QItemEditorFactory *	itemEditorFactory () const
	Returns the editor factory used by the item delegate.

void	setItemEditorFactory (QItemEditorFactory *factory)
	Sets the editor factory to be used by the item delegate to be the factory specified.

virtual QString	displayText (const QVariant &value, const QLocale &locale) const
	This function returns the string that the delegate will use to display the Qt::DisplayRole of the model in locale.

Public Member Functions inherited from QAbstractItemDelegate
	QAbstractItemDelegate (QObject *parent=nullptr)
	Creates a new abstract item delegate with the given parent.

virtual	~QAbstractItemDelegate ()
	Destroys the abstract item delegate.

virtual void	destroyEditor (QWidget *editor, const QModelIndex &index) const
	Called when the editor is no longer needed for editing the data item with the given index and should be destroyed.

virtual bool	helpEvent (QHelpEvent event, QAbstractItemView view, const QStyleOptionViewItem &option, const QModelIndex &index)

virtual QList< int >	paintingRoles () const

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.

virtual	~QObject ()
	Destroys the object, deleting all its child objects.

virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.

QString	objectName () const

Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.

void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const
	Returns `true` if the object is a widget; otherwise returns `false`.

bool	isWindowType () const
	Returns `true` if the object is a window; otherwise returns `false`.

bool	isQuickItemType () const
	Returns `true` if the object is a QQuickItem; otherwise returns `false`.

bool	signalsBlocked () const noexcept
	Returns `true` if signals are blocked; otherwise returns `false`.

bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).

QThread *	thread () const
	Returns the thread in which the object lives.

bool	moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
	Changes the thread affinity for this object and its children and returns `true` on success.

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.

int	startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)
	Kills the timer with timer identifier, id.

void	killTimer (Qt::TimerId id)

template<typename T >
T	findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.

template<typename T >
QList< T >	findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.

template<typename T >
T	findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QObjectList &	children () const
	Returns a list of child objects.

void	setParent (QObject *parent)
	Makes the object a child of parent.

void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.

void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const

bool	disconnect (const char signal=nullptr, const QObject receiver=nullptr, const char *member=nullptr) const

bool	disconnect (const QObject receiver, const char member=nullptr) const

void	dumpObjectTree () const
	Dumps a tree of children to the debug output.

void	dumpObjectInfo () const
	Dumps information about signal connections, etc.

bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.

bool	setProperty (const char *name, QVariant &&value)

QVariant	property (const char *name) const
	Returns the value of the object's name property.

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const
	Returns a pointer to the parent object.

bool	inherits (const char *classname) const
	Returns `true` if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns `false`.

Protected Member Functions
virtual void	initStyleOption (QStyleOptionViewItem *option, const QModelIndex &index) const
	Initialize option with the values using the index index.

bool	eventFilter (QObject object, QEvent event) override
	Returns `true` if the given editor is a valid QWidget and the given event is handled; otherwise returns `false`.

bool	editorEvent (QEvent event, QAbstractItemModel model, const QStyleOptionViewItem &option, const QModelIndex &index) override
	\reimp

Protected Member Functions inherited from QAbstractItemDelegate
	QAbstractItemDelegate (QObjectPrivate &, QObject *parent=nullptr)

Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.

int	senderSignalIndex () const

int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.

virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.

virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Additional Inherited Members
Public Types inherited from QAbstractItemDelegate
enum	EndEditHint { NoHint , EditNextItem , EditPreviousItem , SubmitModelCache , RevertModelCache }
	This enum describes the different hints that the delegate can give to the model and view components to make editing data in a model a comfortable experience for the user. More...

Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Signals inherited from QAbstractItemDelegate
void	commitData (QWidget *editor)
	This signal must be emitted when the editor widget has completed editing the data, and wants to write it back into the model.

void	closeEditor (QWidget *editor, QAbstractItemDelegate::EndEditHint hint=NoHint)
	This signal is emitted when the user has finished editing an item using the specified editor.

void	sizeHintChanged (const QModelIndex &)

Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.

void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.

Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe

static QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)
	\threadsafe

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.

template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object receiver, Func2 slot)

template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject receiver, void **zero)

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Properties inherited from QObject
QString	objectName
	the name of this object

Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

The QStyledItemDelegate class provides display and editing facilities for data items from a model.

\inmodule QtWidgets

Since: 4.4

When displaying data from models in Qt item views, e.g., a QTableView, the individual items are drawn by a delegate. Also, when an item is edited, it provides an editor widget, which is placed on top of the item view while editing takes place. QStyledItemDelegate is the default delegate for all Qt item views, and is installed upon them when they are created.

The QStyledItemDelegate class is one of the \l{Model/View Classes} and is part of Qt's \l{Model/View Programming}{model/view framework}. The delegate allows the display and editing of items to be developed independently from the model and view.

The data of items in models are assigned an \l{Qt::}{ItemDataRole}; each item can store a QVariant for each role. QStyledItemDelegate implements display and editing for the most common datatypes expected by users, including booleans, integers, and strings.

The data will be drawn differently depending on which role they have in the model. The following table describes the roles and the data types the delegate can handle for each of them. It is often sufficient to ensure that the model returns appropriate data for each of the roles to determine the appearance of items in views.

\table \header

Role
Accepted Types \omit \row
\l Qt::AccessibleDescriptionRole
QString \row
\l Qt::AccessibleTextRole
QString \endomit \row
\l Qt::BackgroundRole
QBrush
Since
4.2 \row
\l Qt::CheckStateRole
Qt::CheckState \row
\l Qt::DecorationRole
QIcon, QPixmap, QImage and QColor \row
\l Qt::DisplayRole
QString and types with a string representation \row
\l Qt::EditRole
See QItemEditorFactory for details \row
\l Qt::FontRole
QFont \row
\l Qt::SizeHintRole
QSize \omit \row
\l Qt::StatusTipRole
\endomit \row
\l Qt::TextAlignmentRole
Qt::Alignment \row
\l Qt::ForegroundRole
QBrush
Since
4.2 \omit \row
\l Qt::ToolTipRole \row
\l Qt::WhatsThisRole \endomit \endtable

Editors are created with a QItemEditorFactory; a default static instance provided by QItemEditorFactory is installed on all item delegates. You can set a custom factory using setItemEditorFactory() or set a new default factory with QItemEditorFactory::setDefaultFactory().

QItemEditorFactory *editorFactory = new QItemEditorFactory;
QItemEditorCreatorBase *creator = new QStandardItemEditorCreator<MyFancyDateTimeEdit>();
editorFactory->registerEditor(QMetaType::QDateTime, creator);
 
QItemEditorFactory::setDefaultFactory(editorFactory);

After the new factory has been set, all standard item delegates will use it (i.e, also delegates that were created before the new default factory was set).

It is the data stored in the item model with the \l{Qt::}{EditRole} that is edited. See the QItemEditorFactory class for a more high-level introduction to item editor factories.

Definition at line 20 of file qstyleditemdelegate.h.

Constructor & Destructor Documentation

◆ QStyledItemDelegate()

QStyledItemDelegate::QStyledItemDelegate ( QObject * parent = nullptr )

explicit

Constructs an item delegate with the given parent.

Definition at line 219 of file qstyleditemdelegate.cpp.

◆ ~QStyledItemDelegate()

QStyledItemDelegate::~QStyledItemDelegate ( )

Destroys the item delegate.

Definition at line 227 of file qstyleditemdelegate.cpp.

Member Function Documentation

◆ createEditor()

QWidget * QStyledItemDelegate::createEditor	(	QWidget *	parent,
		const QStyleOptionViewItem &	option,
		const QModelIndex &	index ) const

overridevirtual

Returns the widget used to edit the item specified by index for editing.

The parent widget and style option are used to control how the editor widget appears.

See also: QAbstractItemDelegate::createEditor()

Reimplemented from QAbstractItemDelegate.

Reimplemented in SpinBoxDelegate.

Definition at line 412 of file qstyleditemdelegate.cpp.

References d, Qt::EditRole, QObject::parent(), and Q_UNUSED.

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◆ displayText()

QString QStyledItemDelegate::displayText	(	const QVariant &	value,
		const QLocale &	locale ) const

virtual

This function returns the string that the delegate will use to display the Qt::DisplayRole of the model in locale.

value is the value of the Qt::DisplayRole provided by the model.

The default implementation uses the QLocale::toString to convert value into a QString.

This function is not called for empty model indices, i.e., indices for which the model returns an invalid QVariant.

See also: QAbstractItemModel::data()

Definition at line 244 of file qstyleditemdelegate.cpp.

References Qt::DisplayRole.

Referenced by initStyleOption().

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◆ editorEvent()

bool QStyledItemDelegate::editorEvent	(	QEvent *	event,
		QAbstractItemModel *	model,
		const QStyleOptionViewItem &	option,
		const QModelIndex &	index )

overrideprotectedvirtual

\reimp

Reimplemented from QAbstractItemDelegate.

Definition at line 557 of file qstyleditemdelegate.cpp.

References QSinglePointEvent::button(), Qt::Checked, Qt::CheckStateRole, QVariant::data(), QAbstractTableModel::flags(), initStyleOption(), Qt::ItemIsEnabled, Qt::ItemIsUserCheckable, Qt::ItemIsUserTristate, QKeyEvent::key(), Qt::Key_Select, Qt::Key_Space, QEvent::KeyPress, Qt::LeftButton, model, QEvent::MouseButtonDblClick, QEvent::MouseButtonPress, QEvent::MouseButtonRelease, QSinglePointEvent::position(), Q_ASSERT, QStyle::SE_ItemViewItemCheckIndicator, QAbstractItemModel::setData(), state, QStyle::State_Enabled, QApplication::style(), QWidget::style(), QStyle::subElementRect(), QPointF::toPoint(), Qt::Unchecked, widget, and QStyledItemDelegatePrivate::widget().

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◆ eventFilter()

bool QStyledItemDelegate::eventFilter	(	QObject *	editor,
		QEvent *	event )

overrideprotectedvirtual

Returns true if the given editor is a valid QWidget and the given event is handled; otherwise returns false.

The following key press events are handled by default:

\list

\uicontrol Tab
\uicontrol Backtab
\uicontrol Enter
\uicontrol Return
\uicontrol Esc \endlist

If the editor's type is QTextEdit or QPlainTextEdit then \uicontrol Tab, \uicontrol Backtab, \uicontrol Enter and \uicontrol Return keys are not handled.

In the case of \uicontrol Tab, \uicontrol Backtab, \uicontrol Enter and \uicontrol Return key press events, the editor's data is committed to the model and the editor is closed. If the event is a \uicontrol Tab key press the view will open an editor on the next item in the view. Likewise, if the event is a \uicontrol Backtab key press the view will open an editor on the previous item in the view.

If the event is a \uicontrol Esc key press event, the editor is closed without committing its data.

See also: commitData(), closeEditor()

Reimplemented from QObject.

Definition at line 548 of file qstyleditemdelegate.cpp.

References d.

◆ initStyleOption()

void QStyledItemDelegate::initStyleOption	(	QStyleOptionViewItem *	option,
		const QModelIndex &	index ) const

protectedvirtual

Initialize option with the values using the index index.

This method is useful for subclasses when they need a QStyleOptionViewItem, but don't want to fill in all the information themselves.

See also: QStyleOption::initFrom()

Reimplemented in QSideBarDelegate.

Definition at line 256 of file qstyleditemdelegate.cpp.

References Qt::BackgroundRole, Qt::CheckStateRole, d, Qt::DecorationRole, QIcon::Disabled, Qt::DisplayRole, displayText(), Qt::FontRole, Qt::ForegroundRole, QPixmap::fromImage(), QSize::height(), QIcon::Normal, QIcon::Off, QIcon::On, pixmap, qMin(), QIcon::Selected, state, QStyle::State_Enabled, QStyle::State_Open, QStyle::State_Selected, QPalette::Text, Qt::TextAlignmentRole, and QSize::width().

Referenced by editorEvent(), QSideBarDelegate::initStyleOption(), paint(), sizeHint(), and updateEditorGeometry().

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◆ itemEditorFactory()

QItemEditorFactory * QStyledItemDelegate::itemEditorFactory ( ) const

Returns the editor factory used by the item delegate.

If no editor factory is set, the function will return null.

See also: setItemEditorFactory()

Definition at line 497 of file qstyleditemdelegate.cpp.

References d.

◆ paint()

void QStyledItemDelegate::paint	(	QPainter *	painter,
		const QStyleOptionViewItem &	option,
		const QModelIndex &	index ) const

overridevirtual

Renders the delegate using the given painter and style option for the item specified by index.

This function paints the item using the view's QStyle.

When reimplementing paint in a subclass. Use the initStyleOption() to set up the option in the same way as the QStyledItemDelegate.

Whenever possible, use the option while painting. Especially its \l{QStyleOption::}{rect} variable to decide where to draw and its \l{QStyleOption::}{state} to determine if it is enabled or selected.

After painting, you should ensure that the painter is returned to the state it was supplied in when this function was called. For example, it may be useful to call QPainter::save() before painting and QPainter::restore() afterwards.

See also: QItemDelegate::paint(), QStyle::drawControl(), QStyle::CE_ItemViewItem

Implements QAbstractItemDelegate.

Definition at line 368 of file qstyleditemdelegate.cpp.

References QStyle::CE_ItemViewItem, QStyle::drawControl(), initStyleOption(), opt, painter, Q_ASSERT, QApplication::style(), QWidget::style(), widget, and QStyledItemDelegatePrivate::widget().

Referenced by QCompleterItemDelegate::paint(), QtPrivate::QCalendarDelegate::paint(), QComboBoxDelegate::paint(), and QtPrivate::QCalendarDelegate::paintCell().

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◆ setEditorData()

void QStyledItemDelegate::setEditorData	(	QWidget *	editor,
		const QModelIndex &	index ) const

overridevirtual

Sets the data to be displayed and edited by the editor from the data model item specified by the model index.

The default implementation stores the data in the editor widget's \l {Qt's Property System} {user property}.

See also: QMetaProperty::isUser()

Reimplemented from QAbstractItemDelegate.

Reimplemented in SpinBoxDelegate.

Definition at line 432 of file qstyleditemdelegate.cpp.

References QVariant::data(), and Qt::EditRole.

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◆ setItemEditorFactory()

void QStyledItemDelegate::setItemEditorFactory ( QItemEditorFactory * factory )

Sets the editor factory to be used by the item delegate to be the factory specified.

If no editor factory is set, the item delegate will use the default editor factory.

See also: itemEditorFactory()

Definition at line 510 of file qstyleditemdelegate.cpp.

References d, and factory.

◆ setModelData()

void QStyledItemDelegate::setModelData	(	QWidget *	editor,
		QAbstractItemModel *	model,
		const QModelIndex &	index ) const

overridevirtual

Gets data from the editor widget and stores it in the specified model at the item index.

The default implementation gets the value to be stored in the data model from the editor widget's \l {Qt's Property System} {user property}.

See also: QMetaProperty::isUser()

Reimplemented from QAbstractItemDelegate.

Reimplemented in SpinBoxDelegate.

Definition at line 454 of file qstyleditemdelegate.cpp.

References d, QSqlQueryModel::data(), Qt::EditRole, model, Q_ASSERT, QAbstractItemModel::setData(), and QVariant::userType().

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◆ sizeHint()

QSize QStyledItemDelegate::sizeHint	(	const QStyleOptionViewItem &	option,
		const QModelIndex &	index ) const

overridevirtual

Returns the size needed by the delegate to display the item specified by index, taking into account the style information provided by option.

This function uses the view's QStyle to determine the size of the item.

See also: QStyle::sizeFromContents(), QStyle::CT_ItemViewItem

Implements QAbstractItemDelegate.

Definition at line 391 of file qstyleditemdelegate.cpp.

References QStyle::CT_ItemViewItem, QVariant::data(), initStyleOption(), opt, QStyle::sizeFromContents(), Qt::SizeHintRole, QApplication::style(), QWidget::style(), widget, and QStyledItemDelegatePrivate::widget().

Referenced by QComboBoxDelegate::sizeHint().

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◆ updateEditorGeometry()

void QStyledItemDelegate::updateEditorGeometry	(	QWidget *	editor,
		const QStyleOptionViewItem &	option,
		const QModelIndex &	index ) const

overridevirtual

Updates the editor for the item specified by index according to the style option given.

Reimplemented from QAbstractItemDelegate.

Reimplemented in SpinBoxDelegate.

Definition at line 473 of file qstyleditemdelegate.cpp.

References initStyleOption(), opt, Q_ASSERT, QStyle::SE_ItemViewItemText, QStyle::SH_ItemView_ShowDecorationSelected, QApplication::style(), QWidget::style(), QStyle::subElementRect(), widget, and QStyledItemDelegatePrivate::widget().

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The documentation for this class was generated from the following files:

qtbase/src/widgets/itemviews/qstyleditemdelegate.h (05fc3aef53348fb58be6308076e000825b704e58)
qtbase/src/widgets/itemviews/qstyleditemdelegate.cpp (4e1a1f3697563124588d7d00089b15084220ca42)

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QStyledItemDelegate()

◆ ~QStyledItemDelegate()

Member Function Documentation

◆ createEditor()

◆ displayText()

◆ editorEvent()

◆ eventFilter()

◆ initStyleOption()

◆ itemEditorFactory()

◆ paint()

◆ setEditorData()

◆ setItemEditorFactory()

◆ setModelData()

◆ sizeHint()

◆ updateEditorGeometry()