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

#include <qitemdelegate.h>

Inheritance diagram for QItemDelegate:

Collaboration diagram for QItemDelegate:

Public Member Functions
	QItemDelegate (QObject *parent=nullptr)

	~QItemDelegate ()

bool	hasClipping () const

void	setClipping (bool clip)

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

QSize	sizeHint (const QStyleOptionViewItem &option, const QModelIndex &index) const override

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

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

void	setModelData (QWidget editor, QAbstractItemModel model, const QModelIndex &index) const override

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

QItemEditorFactory *	itemEditorFactory () const

void	setItemEditorFactory (QItemEditorFactory *factory)

Public Member Functions inherited from QAbstractItemDelegate
	QAbstractItemDelegate (QObject *parent=nullptr)

virtual	~QAbstractItemDelegate ()

virtual void	destroyEditor (QWidget *editor, const QModelIndex &index) const

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)

virtual	~QObject ()

virtual bool	event (QEvent *event)

QString	objectName () const

void	setObjectName (const QString &name)

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const

bool	isWindowType () const

bool	signalsBlocked () const noexcept

bool	blockSignals (bool b) noexcept

QThread *	thread () const

void	moveToThread (QThread *thread)

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)

template<typename T >
T	findChild (const QString &aName=QString(), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (const QString &aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

const QObjectList &	children () const

void	setParent (QObject *parent)

void	installEventFilter (QObject *filterObj)

void	removeEventFilter (QObject *obj)

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

void	dumpObjectInfo () const

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

QVariant	property (const char *name) const

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const

bool	inherits (const char *classname) const

Protected Member Functions
virtual void	drawDisplay (QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect, const QString &text) const

virtual void	drawDecoration (QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect, const QPixmap &pixmap) const

virtual void	drawFocus (QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect) const

virtual void	drawCheck (QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect, Qt::CheckState state) const

void	drawBackground (QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const

void	doLayout (const QStyleOptionViewItem &option, QRect checkRect, QRect iconRect, QRect *textRect, bool hint) const

QRect	rect (const QStyleOptionViewItem &option, const QModelIndex &index, int role) const

bool	eventFilter (QObject object, QEvent event) override

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

QStyleOptionViewItem	setOptions (const QModelIndex &index, const QStyleOptionViewItem &option) const

QPixmap	decoration (const QStyleOptionViewItem &option, const QVariant &variant) const

QRect	doCheck (const QStyleOptionViewItem &option, const QRect &bounding, const QVariant &variant) const

QRect	textRectangle (QPainter *painter, const QRect &rect, const QFont &font, const QString &text) const

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

Protected Member Functions inherited from QObject
QObject *	sender () const

int	senderSignalIndex () const

int	receivers (const char *signal) const

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)

virtual void	childEvent (QChildEvent *event)

virtual void	customEvent (QEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

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

Static Protected Member Functions
static QPixmap	selectedPixmap (const QPixmap &pixmap, const QPalette &palette, bool enabled)

Properties
bool	clipping
	if the delegate should clip the paint events More...

Properties inherited from QObject
QString	objectName
	the name of this object More...

Additional Inherited Members
Public Types inherited from QAbstractItemDelegate
enum	EndEditHint { NoHint , EditNextItem , EditPreviousItem , SubmitModelCache , RevertModelCache }

Public Slots inherited from QObject
void	deleteLater ()

Signals inherited from QAbstractItemDelegate
void	commitData (QWidget *editor)

void	closeEditor (QWidget *editor, QAbstractItemDelegate::EndEditHint hint=NoHint)

void	sizeHintChanged (const QModelIndex &)

Signals inherited from QObject
void	destroyed (QObject *=nullptr)

void	objectNameChanged (const QString &objectName, QPrivateSignal)

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)

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::FunctionPointer< Func2 >::Object receiver, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

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

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

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 slot)

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject context, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

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

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

static bool	disconnect (const QMetaObject::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

Related Functions inherited from QObject
template< class T > T	qobject_cast (const QObject *object)

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

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

	QObjectList

Detailed Description

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

\inmodule QtWidgets

QItemDelegate can be used to provide custom display features and editor widgets for item views based on QAbstractItemView subclasses. Using a delegate for this purpose allows the display and editing mechanisms to be customized and developed independently from the model and view.

The QItemDelegate class is one of the \l{Model/View Classes} and is part of Qt's \l{Model/View Programming}{model/view framework}. Note that QStyledItemDelegate has taken over the job of drawing Qt's item views. We recommend the use of QStyledItemDelegate when creating new delegates.

When displaying items from a custom model in a standard view, it is often sufficient to simply ensure that the model returns appropriate data for each of the \l{Qt::ItemDataRole}{roles} that determine the appearance of items in views. The default delegate used by Qt's standard views uses this role information to display items in most of the common forms expected by users. However, it is sometimes necessary to have even more control over the appearance of items than the default delegate can provide.

This class provides default implementations of the functions for painting item data in a view and editing data from item models. Default implementations of the paint() and sizeHint() virtual functions, defined in QAbstractItemDelegate, are provided to ensure that the delegate implements the correct basic behavior expected by views. You can reimplement these functions in subclasses to customize the appearance of items.

When editing data in an item view, QItemDelegate provides an editor widget, which is a widget that is placed on top of the view while editing takes place. 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(). It is the data stored in the item model with the Qt::EditRole that is edited.

Only the standard editing functions for widget-based delegates are reimplemented here:

\list

createEditor() returns the widget used to change data from the model and can be reimplemented to customize editing behavior.
setEditorData() provides the widget with data to manipulate.
updateEditorGeometry() ensures that the editor is displayed correctly with respect to the item view.
setModelData() returns updated data to the model. \endlist

The closeEditor() signal indicates that the user has completed editing the data, and that the editor widget can be destroyed.

Definition at line 56 of file qitemdelegate.h.

Constructor & Destructor Documentation

◆ QItemDelegate()

QItemDelegate::QItemDelegate ( QObject * parent = nullptr )

explicit

Constructs an item delegate with the given parent.

Definition at line 329 of file qitemdelegate.cpp.

◆ ~QItemDelegate()

QItemDelegate::~QItemDelegate ( )

Destroys the item delegate.

Definition at line 339 of file qitemdelegate.cpp.

Member Function Documentation

◆ createEditor()

QWidget * QItemDelegate::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 ChooseEditorDelegate, and ExampleDelegate.

Definition at line 498 of file qitemdelegate.cpp.

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◆ decoration()

QPixmap QItemDelegate::decoration	(	const QStyleOptionViewItem &	option,
		const QVariant &	variant
	)		const

protected

Definition at line 970 of file qitemdelegate.cpp.

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◆ doCheck()

QRect QItemDelegate::doCheck	(	const QStyleOptionViewItem &	option,
		const QRect &	bounding,
		const QVariant &	variant
	)		const

protected

Definition at line 1083 of file qitemdelegate.cpp.

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◆ doLayout()

void QItemDelegate::doLayout	(	const QStyleOptionViewItem &	option,
		QRect *	checkRect,
		QRect *	iconRect,
		QRect *	textRect,
		bool	hint
	)		const

protected

Definition at line 832 of file qitemdelegate.cpp.

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◆ drawBackground()

void QItemDelegate::drawBackground	(	QPainter *	painter,
		const QStyleOptionViewItem &	option,
		const QModelIndex &	index
	)		const

protected

Since: 4.2

Renders the item background for the given index, using the given painter and style option.

Definition at line 803 of file qitemdelegate.cpp.

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◆ drawCheck()

void QItemDelegate::drawCheck	(	QPainter *	painter,
		const QStyleOptionViewItem &	option,
		const QRect &	rect,
		Qt::CheckState	state
	)		const

protectedvirtual

Renders a check indicator within the rectangle specified by rect, using the given painter and style option, using the given state.

Definition at line 767 of file qitemdelegate.cpp.

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◆ drawDecoration()

void QItemDelegate::drawDecoration	(	QPainter *	painter,
		const QStyleOptionViewItem &	option,
		const QRect &	rect,
		const QPixmap &	pixmap
	)		const

protectedvirtual

Renders the decoration pixmap within the rectangle specified by rect using the given painter and style option.

Reimplemented in TestItemDelegate.

Definition at line 712 of file qitemdelegate.cpp.

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◆ drawDisplay()

void QItemDelegate::drawDisplay	(	QPainter *	painter,
		const QStyleOptionViewItem &	option,
		const QRect &	rect,
		const QString &	text
	)		const

protectedvirtual

Renders the item view text within the rectangle specified by rect using the given painter and style option.

Reimplemented in TestItemDelegate.

Definition at line 626 of file qitemdelegate.cpp.

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◆ drawFocus()

void QItemDelegate::drawFocus	(	QPainter *	painter,
		const QStyleOptionViewItem &	option,
		const QRect &	rect
	)		const

protectedvirtual

Renders the region within the rectangle specified by rect, indicating that it has the focus, using the given painter and style option.

Definition at line 740 of file qitemdelegate.cpp.

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◆ editorEvent()

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

overrideprotectedvirtual

\reimp

Reimplemented from QAbstractItemDelegate.

Reimplemented in TestItemDelegate.

Definition at line 1154 of file qitemdelegate.cpp.

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◆ eventFilter()

bool QItemDelegate::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

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.

Reimplemented in TestItemDelegate.

Definition at line 1144 of file qitemdelegate.cpp.

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◆ hasClipping()

bool QItemDelegate::hasClipping ( ) const

Definition at line 353 of file qitemdelegate.cpp.

◆ itemEditorFactory()

QItemEditorFactory * QItemDelegate::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 602 of file qitemdelegate.cpp.

◆ paint()

void QItemDelegate::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.

When reimplementing this function in a subclass, you should update the area held by the option's \l{QStyleOption::rect}{rect} variable, using the option's \l{QStyleOption::state}{state} variable to determine the state of the item to be displayed, and adjust the way it is painted accordingly.

For example, a selected item may need to be displayed differently to unselected items, as shown in the following code:

\dots

After painting, you should ensure that the painter is returned to its 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: QStyle::State

Implements QAbstractItemDelegate.

Definition at line 392 of file qitemdelegate.cpp.

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◆ rect()

QRect QItemDelegate::rect	(	const QStyleOptionViewItem &	option,
		const QModelIndex &	index,
		int	role
	)		const

protected

Definition at line 1042 of file qitemdelegate.cpp.

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◆ selectedPixmap()

QPixmap QItemDelegate::selectedPixmap	(	const QPixmap &	pixmap,
		const QPalette &	palette,
		bool	enabled
	)

staticprotected

Definition at line 1012 of file qitemdelegate.cpp.

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◆ setClipping()

void QItemDelegate::setClipping ( bool clip )

Definition at line 359 of file qitemdelegate.cpp.

◆ setEditorData()

void QItemDelegate::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 ExampleDelegate.

Definition at line 524 of file qitemdelegate.cpp.

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◆ setItemEditorFactory()

void QItemDelegate::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 615 of file qitemdelegate.cpp.

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◆ setModelData()

void QItemDelegate::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.

Definition at line 552 of file qitemdelegate.cpp.

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◆ setOptions()

QStyleOptionViewItem QItemDelegate::setOptions	(	const QModelIndex &	index,
		const QStyleOptionViewItem &	option
	)		const

protected

Definition at line 1209 of file qitemdelegate.cpp.

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◆ sizeHint()

QSize QItemDelegate::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.

When reimplementing this function, note that in case of text items, QItemDelegate adds a margin (i.e. 2 * QStyle::PM_FocusFrameHMargin) to the length of the text.

Implements QAbstractItemDelegate.

Definition at line 474 of file qitemdelegate.cpp.

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◆ textRectangle()

QRect QItemDelegate::textRectangle	(	QPainter *	painter,
		const QRect &	rect,
		const QFont &	font,
		const QString &	text
	)		const

protected

Definition at line 1101 of file qitemdelegate.cpp.

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◆ updateEditorGeometry()

void QItemDelegate::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.

Definition at line 578 of file qitemdelegate.cpp.

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Property Documentation

◆ clipping

QItemDelegate::clipping

readwrite

if the delegate should clip the paint events

Since: 4.2

This property will set the paint clip to the size of the item. The default value is on. It is useful for cases such as when images are larger than the size of the item.

Definition at line 129 of file qitemdelegate.h.

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

src/widgets/itemviews/qitemdelegate.h
src/widgets/itemviews/qitemdelegate.cpp

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Properties

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QItemDelegate()

◆ ~QItemDelegate()

Member Function Documentation

◆ createEditor()

◆ decoration()

◆ doCheck()

◆ doLayout()

◆ drawBackground()

◆ drawCheck()

◆ drawDecoration()

◆ drawDisplay()

◆ drawFocus()

◆ editorEvent()

◆ eventFilter()

◆ hasClipping()

◆ itemEditorFactory()

◆ paint()

◆ rect()

◆ selectedPixmap()

◆ setClipping()

◆ setEditorData()

◆ setItemEditorFactory()

◆ setModelData()

◆ setOptions()

◆ sizeHint()

◆ textRectangle()

◆ updateEditorGeometry()

Property Documentation

◆ clipping