The QDataWidgetMapper class provides mapping between a section of a data model to widgets. More...

Inheritance diagram for QDataWidgetMapper:

Public Types
enum	SubmitPolicy

Public Signals
void	currentIndexChanged (int index)

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

void	objectNameChanged (const QString &objectName)

Public Slots
void	revert ()

virtual void	setCurrentIndex (int index)

void	setCurrentModelIndex (const QModelIndex &index)

bool	submit ()

void	toFirst ()

void	toLast ()

void	toNext ()

void	toPrevious ()

Public Slots inherited from QObject
void	deleteLater ()

Public Methods
	QDataWidgetMapper (QObject *parent=nullptr)

	~QDataWidgetMapper ()

void	addMapping (QWidget *widget, int section)

void	addMapping (QWidget *widget, int section, const QString &propertyName)

void	clearMapping ()

int	currentIndex () const

QAbstractItemDelegate *	itemDelegate () const

QString	mappedPropertyName (QWidget *widget) const

int	mappedSection (QWidget *widget) const

QWidget *	mappedWidgetAt (int section) const

QAbstractItemModel *	model () const

Qt::Orientation	orientation () const

void	removeMapping (QWidget *widget)

QModelIndex	rootIndex () const

void	setItemDelegate (QAbstractItemDelegate *delegate)

void	setModel (QAbstractItemModel *model)

void	setOrientation (Qt::Orientation newOrientation)

void	setRootIndex (const QModelIndex &index)

void	setSubmitPolicy (SubmitPolicy policy)

SubmitPolicy	submitPolicy () const

Public Methods inherited from QObject
	QObject (QObject *parent=nullptr)

	~QObject ()

bool	blockSignals (bool block)

const QList< QObject * > &	children () const

bool	connect (const QObject *sender, const QString &signalMethod, const QString &location, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	connect (const QObject *sender, const QString &signalMethod, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	disconnect (const QObject *receiver, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod, const QString &location, const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod=QString (), const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QString >	dynamicPropertyNames () const

virtual bool	event (QEvent *event)

virtual bool	eventFilter (QObject watched, QEvent event)

template<typename T >
T	findChild (const QString &childName=QString ()) const

template<class T >
QList< T >	findChildren (const QRegularExpression &regExp, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

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

bool	inherits (const QString &className) const

void	installEventFilter (QObject *filterObj)

bool	isWidgetType () const

bool	isWindowType () const

void	killTimer (int id)

const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

QString	objectName () const

QObject *	parent () const

template<class T = QVariant>
T	property (const QString &name) const

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const QString &name, const QVariant &value)

bool	signalsBlocked () const

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

QThread *	thread () const

Properties
	currentIndex

	orientation

	submitPolicy

Properties inherited from QObject
	objectName

Additional Inherited Members
Static Public Methods inherited from QObject
static bool	connect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

static bool	connect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection, const QString &location=QString ())

static bool	connect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...), Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotLambda, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, std::nullptr_t, const QObject receiver, std::nullptr_t)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...))

template<class Sender , class SignalClass , class... SignalArgs, class Receiver >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, std::nullptr_t slotMethod=nullptr)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotMethod)

static QMetaObject &	staticMetaObject ()

static QString	tr (const char text, const char comment=nullptr, std::optional< int > numArg=std::optional< int >())

Protected Methods inherited from QObject
virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const QMetaMethod &signalMethod) const

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signalMethod) const

bool	isSignalConnected (const QMetaMethod &signalMethod) const

int	receivers (const QString &signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Related Functions inherited from QObject
T	qobject_cast (QObject *object)

	QObjectList

Detailed Description

The QDataWidgetMapper class provides mapping between a section of a data model to widgets.

QDataWidgetMapper can be used to create data-aware widgets by mapping them to sections of an item model. A section is a column of a model if the orientation is horizontal (the default), otherwise a row.

Every time the current index changes, each widget is updated with data from the model via the property specified when its mapping was made. If the user edits the contents of a widget, the changes are read using the same property and written back to the model. By default, each widget's user property is used to transfer data between the model and the widget. An additional addMapping() function enables a named property to be used instead of the default user property.

It is possible to set an item delegate to support custom widgets. By default, a QItemDelegate is used to synchronize the model with the widgets.

Let us assume that we have an item model named model with the following contents:

1	Canada	Montreal
2	Australia	Darwin
3	USA	San Francisco
4	China	Beijing
5	France	Paris

The following code will map the columns of the model to widgets called mySpinBox, myLineEdit and myCountryChooser:

QDataWidgetMapper *mapper = new QDataWidgetMapper;
mapper->setModel(model);
mapper->addMapping(mySpinBox, 0);
mapper->addMapping(myLineEdit, 1);
mapper->addMapping(myCountryChooser, 2);
mapper->toFirst();

After the call to toFirst, mySpinBox displays the value 1, myLineEdit displays Canada and myCountryChooser displays Montreal. The navigational functions toFirst(), toNext(), toPrevious(), toLast() and setCurrentIndex() can be used to navigate in the model and update the widgets with contents from the model.

The setRootIndex() function enables a particular item in a model to be specified as the root index - children of this item will be mapped to the relevant widgets in the user interface.

QDataWidgetMapper supports two submit policies, AutoSubmit and ManualSubmit. AutoSubmit will update the model as soon as the current widget loses focus, ManualSubmit will not update the model unless submit() is called. ManualSubmit is useful when displaying a dialog that lets the user cancel all modifications. Also, other views that display the model will not update until the user finishes all their modifications and submits.

Note that QDataWidgetMapper keeps track of external modifications. If the contents of the model are updated in another module of the application, the widgets are updated as well.

See also: QAbstractItemModel, QAbstractItemDelegate

Member Enumeration Documentation

enum QDataWidgetMapper::SubmitPolicy

This enum describes the possible submit policies a QDataWidgetMapper supports.

Constant	Value	Description
`QDataWidgetMapper::AutoSubmit`	`0`	Whenever a widget loses focus, the widget's current value is set to the item model.
`QDataWidgetMapper::ManualSubmit`	`1`	The model is not updated until submit() is called.

Constructor & Destructor Documentation

QDataWidgetMapper::QDataWidgetMapper ( QObject * parent = nullptr )

explicit

Constructs a new QDataWidgetMapper with parent object parent. By default, the orientation is horizontal and the submit policy is AutoSubmit.

See also: setOrientation(), setSubmitPolicy()

QDataWidgetMapper::~QDataWidgetMapper ( )

Destroys the object.

Method Documentation

void QDataWidgetMapper::addMapping	(	QWidget *	widget,
		int	section
	)

Adds a mapping between a widget and a section from the model. The section is a column in the model if the orientation is horizontal (the default), otherwise a row.

For the following example, we assume a model myModel that has two columns: the first one contains the names of people in a group, and the second column contains their ages. The first column is mapped to the QLineEdit nameLineEdit, and the second is mapped to the QSpinBox ageSpinBox:

QDataWidgetMapper *mapper = new QDataWidgetMapper();
mapper->setModel(myModel);
mapper->addMapping(nameLineEdit, 0);
mapper->addMapping(ageSpinBox, 1);

If the widget is already mapped to a section, the old mapping will be replaced by the new one.
Only one-to-one mappings between sections and widgets are allowed. It is not possible to map a single section to multiple widgets, or to map a single widget to multiple sections.

See also: removeMapping(), mappedSection(), clearMapping()

void QDataWidgetMapper::addMapping	(	QWidget *	widget,
		int	section,
		const QString &	propertyName
	)

Essentially the same as addMapping(), but adds the possibility to specify the property to use specifying propertyName.

See also: addMapping()

void QDataWidgetMapper::clearMapping ( )

Clears all mappings.

See also: addMapping(), removeMapping()

int QDataWidgetMapper::currentIndex ( ) const

Returns the value of the property.

void QDataWidgetMapper::currentIndexChanged ( int index )

signal

This signal is emitted after the current index has changed and all widgets were populated with new data. index is the new current index.

See also: currentIndex(), setCurrentIndex()

QAbstractItemDelegate * QDataWidgetMapper::itemDelegate ( ) const

Returns the current item delegate.

See also: setItemDelegate()

QString QDataWidgetMapper::mappedPropertyName ( QWidget * widget ) const

Returns the name of the property that is used when mapping data to the given widget.

See also: mappedSection(), addMapping(), removeMapping()

int QDataWidgetMapper::mappedSection ( QWidget * widget ) const

Returns the section the widget is mapped to or -1 if the widget is not mapped.

See also: addMapping(), removeMapping()

QWidget * QDataWidgetMapper::mappedWidgetAt ( int section ) const

Returns the widget that is mapped at section or a nullptr if no widget is mapped at that section.

See also: addMapping(), removeMapping()

QAbstractItemModel * QDataWidgetMapper::model ( ) const

Returns the current model.

See also: setModel()

Qt::Orientation QDataWidgetMapper::orientation ( ) const

Returns the value of the property.

void QDataWidgetMapper::removeMapping ( QWidget * widget )

Removes the mapping for the given widget.

See also: addMapping(), clearMapping()

void QDataWidgetMapper::revert ( )

slot

Repopulates all widgets with the current data of the model. All unsubmitted changes will be lost.

See also: submit(), setSubmitPolicy()

QModelIndex QDataWidgetMapper::rootIndex ( ) const

Returns the current root index.

See also: setRootIndex()

void QDataWidgetMapper::setCurrentIndex ( int index )

slot

Sets the value of the property to index.

void QDataWidgetMapper::setCurrentModelIndex ( const QModelIndex & index )

slot

Sets the current index to the row of the index if the orientation is horizontal (the default), otherwise to the column of the index.

Calls setCurrentIndex() internally. This convenience slot can be connected to the signal currentRowChanged() or currentColumnChanged() of another view's selection model.

The following example illustrates how to update all widgets with new data whenever the selection of a QTableView named myTableView changes:

QDataWidgetMapper *mapper = new QDataWidgetMapper();
connect(myTableView->selectionModel(), SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
        mapper, SLOT(setCurrentModelIndex(QModelIndex)));

See also: currentIndex()

void QDataWidgetMapper::setItemDelegate ( QAbstractItemDelegate * delegate )

Sets the item delegate to delegate. The delegate will be used to write data from the model into the widget and from the widget to the model, using QAbstractItemDelegate::setEditorData() and QAbstractItemDelegate::setModelData().

The delegate also decides when to apply data and when to change the editor, using QAbstractItemDelegate::commitData() and QAbstractItemDelegate::closeEditor().

Warning: You should not share the same instance of a delegate between 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 QDataWidgetMapper::setModel ( QAbstractItemModel * model )

Sets the current model to model. If another model was set, all mappings to that old model are cleared.

See also: model()

void QDataWidgetMapper::setOrientation ( Qt::Orientation newOrientation )

Sets the value of the property to newOrientation.

void QDataWidgetMapper::setRootIndex ( const QModelIndex & index )

Sets the root item to index. This can be used to display a branch of a tree. Pass an invalid model index to display the top-most branch.

See also: rootIndex()

void QDataWidgetMapper::setSubmitPolicy ( SubmitPolicy policy )

Sets the value of the property to policy.

bool QDataWidgetMapper::submit ( )

slot

Submits all changes from the mapped widgets to the model.

For every mapped section, the item delegate reads the current value from the widget and sets it in the model. Finally, the model's submit() method is invoked.

Returns true if all the values were submitted, otherwise false.

Note: For database models, QSqlQueryModel::lastError() can be used to retrieve the last error.

See also: revert(), setSubmitPolicy()

SubmitPolicy QDataWidgetMapper::submitPolicy ( ) const

Returns the value of the property.

void QDataWidgetMapper::toFirst ( )

slot

Populates the widgets with data from the first row of the model if the orientation is horizontal (the default), otherwise with data from the first column.

This is equivalent to calling setCurrentIndex(0).

See also: toLast(), setCurrentIndex()

void QDataWidgetMapper::toLast ( )

slot

Populates the widgets with data from the last row of the model if the orientation is horizontal (the default), otherwise with data from the last column.

Calls setCurrentIndex() internally.

See also: toFirst(), setCurrentIndex()

void QDataWidgetMapper::toNext ( )

slot

Populates the widgets with data from the next row of the model if the orientation is horizontal (the default), otherwise with data from the next column.

Calls setCurrentIndex() internally. Does nothing if there is no next row in the model.

See also: toPrevious(), setCurrentIndex()

void QDataWidgetMapper::toPrevious ( )

slot

Populates the widgets with data from the previous row of the model if the orientation is horizontal (the default), otherwise with data from the previous column.

Calls setCurrentIndex() internally. Does nothing if there is no previous row in the model.

See also: toNext(), setCurrentIndex()

Property Documentation

QDataWidgetMapper::currentIndex

This property holds the current row or column.

The widgets are populated with data from the row at index if the orientation is horizontal (the default), otherwise with data from the column at index.

See also: setCurrentModelIndex(), toFirst(), toNext(), toPrevious(), toLast()

Properties	Class Methods
read	currentIndex
write	setCurrentIndex
notify	currentIndexChanged

QDataWidgetMapper::orientation

This property holds the orientation of the model.

If the orientation is Qt::Horizontal (the default), a widget is mapped to a column of a data model. The widget will be populated with the model's data from its mapped column and the row that currentIndex() points at.

Use Qt::Horizontal for tabular data that looks like this:

1	Canada	Montreal
2	Australia	Darwin
3	USA	San Francisco
4	China	Beijing
5	France	Paris

If the orientation is set to Qt::Vertical, a widget is mapped to a row. Calling setCurrentIndex() will change the current column. The widget will be populates with the model's data from its mapped row and the column that currentIndex() points at.

Use Qt::Vertical for tabular data that looks like this:

1	2	3	4	5
Canada	Australia	USA	China	France
Montreal	Darwin	San Francisco	Beijing	Paris

Changing the orientation clears all existing mappings.

Properties	Class Methods
read	orientation
write	setOrientation

QDataWidgetMapper::submitPolicy

This property holds the current submit policy.

Changing the current submit policy will revert all widgets to the current data from the model.

Properties	Class Methods
read	submitPolicy
write	setSubmitPolicy

Public Types

Public Signals

Public Slots

Public Methods

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation

Property Documentation