Phonon::ObjectDescriptionModel

Phonon
ObjectDescriptionModel

#include <Phonon/ObjectDescriptionModel>

Inheritance diagram for Phonon::ObjectDescriptionModel< type >:

[legend]

Public Member Functions
	ObjectDescriptionModel (const QList< ObjectDescription< type > > &data, QObject *parent=nullptr)

	ObjectDescriptionModel (QObject *parent=nullptr)

QVariant	data (const QModelIndex &index, int role=Qt::DisplayRole) const override

bool	dropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) override

Qt::ItemFlags	flags (const QModelIndex &index) const override

PHONON_TEMPLATE_CLASS_MEMBER_EXPORT const QMetaObject *	metaObject () const override

QMimeData *	mimeData (const QModelIndexList &indexes) const override

QStringList	mimeTypes () const override

QList< ObjectDescription< type > >	modelData () const

ObjectDescription< type >	modelData (const QModelIndex &index) const

void	moveDown (const QModelIndex &index)

void	moveUp (const QModelIndex &index)

PHONON_TEMPLATE_CLASS_MEMBER_EXPORT void *	qt_metacast (const char *_clname) override

bool	removeRows (int row, int count, const QModelIndex &parent=QModelIndex()) override

int	rowCount (const QModelIndex &parent=QModelIndex()) const override

void	setModelData (const QList< ObjectDescription< type > > &data)

const QMetaObject	staticMetaObject

const QMetaObject	staticMetaObject

const QMetaObject	staticMetaObject

const QMetaObject	staticMetaObject

const QMetaObject	staticMetaObject

const QMetaObject	staticMetaObject

Qt::DropActions	supportedDropActions () const override

int	tupleIndexAtPositionIndex (int positionIndex) const

QList< int >	tupleIndexOrder () const

Public Member Functions inherited from QAbstractListModel
	QAbstractListModel (QObject *parent)

virtual QModelIndex	index (int row, int column, const QModelIndex &parent) const const override

virtual QModelIndex	sibling (int row, int column, const QModelIndex &idx) const const override

Public Member Functions inherited from QAbstractItemModel
	QAbstractItemModel (QObject *parent)

virtual QModelIndex	buddy (const QModelIndex &index) const const

virtual bool	canDropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) const const

virtual bool	canFetchMore (const QModelIndex &parent) const const

bool	checkIndex (const QModelIndex &index, CheckIndexOptions options) const const

virtual bool	clearItemData (const QModelIndex &index)

virtual int	columnCount (const QModelIndex &parent) const const=0

void	columnsAboutToBeInserted (const QModelIndex &parent, int first, int last)

void	columnsAboutToBeMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationColumn)

void	columnsAboutToBeRemoved (const QModelIndex &parent, int first, int last)

void	columnsInserted (const QModelIndex &parent, int first, int last)

void	columnsMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationColumn)

void	columnsRemoved (const QModelIndex &parent, int first, int last)

void	dataChanged (const QModelIndex &topLeft, const QModelIndex &bottomRight, const QList< int > &roles)

virtual void	fetchMore (const QModelIndex &parent)

virtual bool	hasChildren (const QModelIndex &parent) const const

bool	hasIndex (int row, int column, const QModelIndex &parent) const const

virtual QVariant	headerData (int section, Qt::Orientation orientation, int role) const const

void	headerDataChanged (Qt::Orientation orientation, int first, int last)

bool	insertColumn (int column, const QModelIndex &parent)

virtual bool	insertColumns (int column, int count, const QModelIndex &parent)

bool	insertRow (int row, const QModelIndex &parent)

virtual bool	insertRows (int row, int count, const QModelIndex &parent)

virtual QMap< int, QVariant >	itemData (const QModelIndex &index) const const

void	layoutAboutToBeChanged (const QList< QPersistentModelIndex > &parents, QAbstractItemModel::LayoutChangeHint hint)

void	layoutChanged (const QList< QPersistentModelIndex > &parents, QAbstractItemModel::LayoutChangeHint hint)

virtual QModelIndexList	match (const QModelIndex &start, int role, const QVariant &value, int hits, Qt::MatchFlags flags) const const

void	modelAboutToBeReset ()

void	modelReset ()

bool	moveColumn (const QModelIndex &sourceParent, int sourceColumn, const QModelIndex &destinationParent, int destinationChild)

virtual bool	moveColumns (const QModelIndex &sourceParent, int sourceColumn, int count, const QModelIndex &destinationParent, int destinationChild)

bool	moveRow (const QModelIndex &sourceParent, int sourceRow, const QModelIndex &destinationParent, int destinationChild)

virtual bool	moveRows (const QModelIndex &sourceParent, int sourceRow, int count, const QModelIndex &destinationParent, int destinationChild)

virtual void	multiData (const QModelIndex &index, QModelRoleDataSpan roleDataSpan) const const

virtual QModelIndex	parent (const QModelIndex &index) const const=0

bool	removeColumn (int column, const QModelIndex &parent)

virtual bool	removeColumns (int column, int count, const QModelIndex &parent)

bool	removeRow (int row, const QModelIndex &parent)

virtual void	revert ()

virtual QHash< int, QByteArray >	roleNames () const const

void	rowsAboutToBeInserted (const QModelIndex &parent, int start, int end)

void	rowsAboutToBeMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow)

void	rowsAboutToBeRemoved (const QModelIndex &parent, int first, int last)

void	rowsInserted (const QModelIndex &parent, int first, int last)

void	rowsMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow)

void	rowsRemoved (const QModelIndex &parent, int first, int last)

virtual bool	setData (const QModelIndex &index, const QVariant &value, int role)

virtual bool	setHeaderData (int section, Qt::Orientation orientation, const QVariant &value, int role)

virtual bool	setItemData (const QModelIndex &index, const QMap< int, QVariant > &roles)

virtual void	sort (int column, Qt::SortOrder order)

virtual QSize	span (const QModelIndex &index) const const

virtual bool	submit ()

virtual Qt::DropActions	supportedDragActions () const const

Public Member Functions inherited from QObject
	QObject (QObject *parent)

QBindable< QString >	bindableObjectName ()

bool	blockSignals (bool block)

const QObjectList &	children () const const

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

void	deleteLater ()

void	destroyed (QObject *obj)

bool	disconnect (const char signal, const QObject receiver, const char *method) const const

bool	disconnect (const QObject receiver, const char method) const const

void	dumpObjectInfo () const const

void	dumpObjectTree () const const

QList< QByteArray >	dynamicPropertyNames () const const

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

T	findChild (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (Qt::FindChildOptions options) const const

bool	inherits (const char *className) const const

void	installEventFilter (QObject *filterObj)

bool	isQuickItemType () const const

bool	isWidgetType () const const

bool	isWindowType () const const

void	killTimer (int id)

void	moveToThread (QThread *targetThread)

QString	objectName () const const

void	objectNameChanged (const QString &objectName)

QObject *	parent () const const

QVariant	property (const char *name) const const

	Q_CLASSINFO (Name, Value)

	Q_EMIT Q_EMIT

	Q_ENUM (...)

	Q_ENUM_NS (...)

	Q_ENUMS (...)

	Q_FLAG (...)

	Q_FLAG_NS (...)

	Q_FLAGS (...)

	Q_GADGET Q_GADGET

	Q_GADGET_EXPORT (EXPORT_MACRO)

	Q_INTERFACES (...)

	Q_INVOKABLE Q_INVOKABLE

	Q_MOC_INCLUDE Q_MOC_INCLUDE

	Q_NAMESPACE Q_NAMESPACE

	Q_NAMESPACE_EXPORT (EXPORT_MACRO)

	Q_OBJECT Q_OBJECT

	Q_PROPERTY (...)

	Q_REVISION Q_REVISION

	Q_SET_OBJECT_NAME (Object)

	Q_SIGNAL Q_SIGNAL

	Q_SIGNALS Q_SIGNALS

	Q_SLOT Q_SLOT

	Q_SLOTS Q_SLOTS

T	qobject_cast (const QObject *object)

T	qobject_cast (QObject *object)

	QT_NO_NARROWING_CONVERSIONS_IN_CONNECT QT_NO_NARROWING_CONVERSIONS_IN_CONNECT

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setObjectName (QAnyStringView name)

void	setParent (QObject *parent)

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

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

bool	signalsBlocked () const const

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

int	startTimer (std::chrono::milliseconds interval, Qt::TimerType timerType)

QThread *	thread () const const

Static Public Attributes
static PHONON_TEMPLATE_CLASS_MEMBER_EXPORT const QMetaObject	staticMetaObject

Protected Attributes
ObjectDescriptionModelData *const	d

Additional Inherited Members
Public Types inherited from QAbstractItemModel
enum	CheckIndexOption

typedef	CheckIndexOptions

enum	LayoutChangeHint

Public Types inherited from QObject
typedef	QObjectList

Properties inherited from QObject
	objectName

Static Public Member Functions inherited from QObject
QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

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

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject context, Functor functor, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)

bool	disconnect (const QMetaObject::Connection &connection)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

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

bool	disconnect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method)

QString	tr (const char sourceText, const char disambiguation, int n)

Public Attributes inherited from QAbstractItemModel
	DoNotUseParent

	HorizontalSortHint

	IndexIsValid

	NoLayoutChangeHint

	NoOption

	ParentIsInvalid

	VerticalSortHint

Protected Member Functions inherited from QAbstractItemModel
void	beginInsertColumns (const QModelIndex &parent, int first, int last)

void	beginInsertRows (const QModelIndex &parent, int first, int last)

bool	beginMoveColumns (const QModelIndex &sourceParent, int sourceFirst, int sourceLast, const QModelIndex &destinationParent, int destinationChild)

bool	beginMoveRows (const QModelIndex &sourceParent, int sourceFirst, int sourceLast, const QModelIndex &destinationParent, int destinationChild)

void	beginRemoveColumns (const QModelIndex &parent, int first, int last)

void	beginRemoveRows (const QModelIndex &parent, int first, int last)

void	beginResetModel ()

void	changePersistentIndex (const QModelIndex &from, const QModelIndex &to)

void	changePersistentIndexList (const QModelIndexList &from, const QModelIndexList &to)

QModelIndex	createIndex (int row, int column, const void *ptr) const const

QModelIndex	createIndex (int row, int column, quintptr id) const const

void	endInsertColumns ()

void	endInsertRows ()

void	endMoveColumns ()

void	endMoveRows ()

void	endRemoveColumns ()

void	endRemoveRows ()

void	endResetModel ()

QModelIndexList	persistentIndexList () const const

virtual void	resetInternalData ()

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

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signal)

bool	isSignalConnected (const QMetaMethod &signal) const const

int	receivers (const char *signal) const const

QObject *	sender () const const

int	senderSignalIndex () const const

virtual void	timerEvent (QTimerEvent *event)

Detailed Description

template<ObjectDescriptionType type>
class Phonon::ObjectDescriptionModel< type >

The ObjectDescriptionModel class provides a model from a list of ObjectDescription objects.

ObjectDescriptionModel is a readonly model that supplies a list using ObjectDescription::name() for the text and ObjectDescription::description() for the tooltip. If set the properties "icon" and "available" are used to set the decoration and disable the item (disabled only visually, you can still select and drag it).

It also provides the methods moveUp() and moveDown() to order the list. Additionally drag and drop is possible so that QAbstractItemView::InternalMove can be used. The resulting order of the ObjectDescription::index() values can then be retrieved using tupleIndexOrder().

An example use case would be to give the user a QComboBox to select the output device:

QComboBox *cb = new QComboBox(parentWidget);
ObjectDescriptionModel *model = new ObjectDescriptionModel(cb);
model->setModelData(BackendCapabilities::availableAudioOutputDevices());
cb->setModel(model);
cb->setCurrentIndex(0); // select first entry

And to retrieve the selected AudioOutputDevice:

int cbIndex = cb->currentIndex();

AudioOutputDevice selectedDevice = model->modelData(cbIndex);

Phonon::ObjectDescriptionModel::modelData

QList< ObjectDescription< type > > modelData() const

Returns the model data.

Definition objectdescriptionmodel.h:310

Phonon::ObjectDescription

Provides a tuple of enduser visible name and description.

Definition objectdescription.h:183

Author: Matthias Kretz kretz.nosp@m.@kde.nosp@m..org

Definition at line 191 of file objectdescriptionmodel.h.

Constructor & Destructor Documentation

◆ ObjectDescriptionModel() [1/2]

template<ObjectDescriptionType type>

Phonon::ObjectDescriptionModel< type >::ObjectDescriptionModel ( QObject * parent = nullptr )

inlineexplicit

Constructs a ObjectDescription model with the given parent.

Definition at line 282 of file objectdescriptionmodel.h.

◆ ObjectDescriptionModel() [2/2]

template<ObjectDescriptionType type>

Phonon::ObjectDescriptionModel< type >::ObjectDescriptionModel	(	const QList< ObjectDescription< type > > &	data,
		QObject *	parent = nullptr )

inlineexplicit

Constructs a ObjectDescription model with the given parent and the given data.

Definition at line 288 of file objectdescriptionmodel.h.

Member Function Documentation

◆ data()

template<ObjectDescriptionType type>

QVariant Phonon::ObjectDescriptionModel< type >::data	(	const QModelIndex &	index,
		int	role = Qt::DisplayRole ) const

inlineoverridevirtual

Returns data from the item with the given index for the specified role.

If the view requests an invalid index, an invalid variant is returned.

Reimplemented from QAbstractItemModel.

See also: QAbstractItemModel::data; Qt::ItemDataRole

Implements QAbstractItemModel.

Definition at line 227 of file objectdescriptionmodel.h.

◆ dropMimeData()

template<ObjectDescriptionType type>

bool Phonon::ObjectDescriptionModel< type >::dropMimeData	(	const QMimeData *	data,
		Qt::DropAction	action,
		int	row,
		int	column,
		const QModelIndex &	parent )

inlineoverridevirtual

Accept drops from other models of the same ObjectDescriptionType.

If a valid parent is given the dropped items will be inserted above that item.

Reimplemented from QAbstractListModel.

Definition at line 336 of file objectdescriptionmodel.h.

◆ flags()

template<ObjectDescriptionType type>

Qt::ItemFlags Phonon::ObjectDescriptionModel< type >::flags ( const QModelIndex & index ) const

inlineoverridevirtual

Reimplemented to show unavailable devices as disabled (but still selectable).

Reimplemented from QAbstractListModel.

Definition at line 233 of file objectdescriptionmodel.h.

◆ metaObject()

template<ObjectDescriptionType type>

const QMetaObject * Phonon::ObjectDescriptionModel< type >::metaObject ( ) const

overridevirtual

Reimplemented from QObject.

Definition at line 124 of file objectdescriptionmodel.cpp.

◆ mimeData()

template<ObjectDescriptionType type>

QMimeData * Phonon::ObjectDescriptionModel< type >::mimeData ( const QModelIndexList & indexes ) const

inlineoverridevirtual

Returns the MIME data that dropMimeData() can use to create new items.

Reimplemented from QAbstractItemModel.

Definition at line 260 of file objectdescriptionmodel.h.

◆ mimeTypes()

template<ObjectDescriptionType type>

QStringList Phonon::ObjectDescriptionModel< type >::mimeTypes ( ) const

inlineoverridevirtual

Returns a list of supported drag and drop MIME types.

Currently it only supports one type used internally.

Reimplemented from QAbstractItemModel.

Definition at line 356 of file objectdescriptionmodel.h.

◆ modelData() [1/2]

template<ObjectDescriptionType type>

QList< ObjectDescription< type > > Phonon::ObjectDescriptionModel< type >::modelData ( ) const

inline

Returns the model data.

As the order of the list might have changed this can be different to what was set using setModelData().

Definition at line 310 of file objectdescriptionmodel.h.

◆ modelData() [2/2]

template<ObjectDescriptionType type>

ObjectDescription< type > Phonon::ObjectDescriptionModel< type >::modelData ( const QModelIndex & index ) const

inline

Returns one ObjectDescription of the model data for the given index.

Definition at line 322 of file objectdescriptionmodel.h.

◆ moveDown()

template<ObjectDescriptionType type>

void Phonon::ObjectDescriptionModel< type >::moveDown ( const QModelIndex & index )

inline

Moves the item at the given index down.

In the resulting list the items at index.row() and index.row() + 1 are swapped.

Connected views are updated automatically.

Definition at line 276 of file objectdescriptionmodel.h.

◆ moveUp()

template<ObjectDescriptionType type>

void Phonon::ObjectDescriptionModel< type >::moveUp ( const QModelIndex & index )

inline

Moves the item at the given index up.

In the resulting list the items at index.row() and index.row() - 1 are swapped.

Connected views are updated automatically.

Definition at line 268 of file objectdescriptionmodel.h.

◆ qt_metacast()

template<ObjectDescriptionType type>

void * Phonon::ObjectDescriptionModel< type >::qt_metacast ( const char * _clname )

override

Definition at line 130 of file objectdescriptionmodel.cpp.

◆ removeRows()

template<ObjectDescriptionType type>

bool Phonon::ObjectDescriptionModel< type >::removeRows	(	int	row,
		int	count,
		const QModelIndex &	parent = QModelIndex() )

inlineoverridevirtual

Removes count rows starting with the given row.

If a valid parent is given no rows are removed since this is a list model.

Returns true if the rows were successfully removed; otherwise returns false.

Reimplemented from QAbstractItemModel.

Definition at line 348 of file objectdescriptionmodel.h.

◆ rowCount()

template<ObjectDescriptionType type>

int Phonon::ObjectDescriptionModel< type >::rowCount ( const QModelIndex & parent = QModelIndex() ) const

inlineoverridevirtual

Returns the number of rows in the model.

This value corresponds to the size of the list passed through setModelData.

Parameters

parent The optional parent argument is used in most models to specify the parent of the rows to be counted. Because this is a list if a valid parent is specified the result will always be 0.

Reimplemented from QAbstractItemModel.

See also: QAbstractItemModel::rowCount

Implements QAbstractItemModel.

Definition at line 214 of file objectdescriptionmodel.h.

◆ setModelData()

template<ObjectDescriptionType type>

void Phonon::ObjectDescriptionModel< type >::setModelData ( const QList< ObjectDescription< type > > & data )

inline

Sets the model data using the list provided by data.

All previous model data is cleared.

Definition at line 296 of file objectdescriptionmodel.h.

◆ staticMetaObject() [1/6]

const QMetaObject Phonon::ObjectDescriptionModel< AudioOutputDeviceType >::staticMetaObject

Definition at line 104 of file objectdescriptionmodel.cpp.

◆ staticMetaObject() [2/6]

const QMetaObject Phonon::ObjectDescriptionModel< AudioCaptureDeviceType >::staticMetaObject

Definition at line 107 of file objectdescriptionmodel.cpp.

◆ staticMetaObject() [3/6]

const QMetaObject Phonon::ObjectDescriptionModel< VideoCaptureDeviceType >::staticMetaObject

Definition at line 110 of file objectdescriptionmodel.cpp.

◆ staticMetaObject() [4/6]

const QMetaObject Phonon::ObjectDescriptionModel< EffectType >::staticMetaObject

Definition at line 113 of file objectdescriptionmodel.cpp.

◆ staticMetaObject() [5/6]

const QMetaObject Phonon::ObjectDescriptionModel< AudioChannelType >::staticMetaObject

Definition at line 116 of file objectdescriptionmodel.cpp.

◆ staticMetaObject() [6/6]

const QMetaObject Phonon::ObjectDescriptionModel< SubtitleType >::staticMetaObject

Definition at line 119 of file objectdescriptionmodel.cpp.

◆ supportedDropActions()

template<ObjectDescriptionType type>

Qt::DropActions Phonon::ObjectDescriptionModel< type >::supportedDropActions ( ) const

inlineoverridevirtual

This model supports drag and drop to copy or move items.

Reimplemented from QAbstractItemModel.

Definition at line 328 of file objectdescriptionmodel.h.

◆ tupleIndexAtPositionIndex()

template<ObjectDescriptionType type>

int Phonon::ObjectDescriptionModel< type >::tupleIndexAtPositionIndex ( int positionIndex ) const

inline

Returns the ObjectDescription::index for the tuple at the given position positionIndex.

For example a QComboBox will give you the currentIndex as the position in the list. But to select the according AudioOutputDevice using AudioOutputDevice::fromIndex you can use this method.

Parameters

positionIndex The position in the list.

Definition at line 254 of file objectdescriptionmodel.h.

◆ tupleIndexOrder()

template<ObjectDescriptionType type>

QList< int > Phonon::ObjectDescriptionModel< type >::tupleIndexOrder ( ) const

inline

Returns a list of indexes in the same order as they are in the model.

The indexes come from the ObjectDescription::index method.

This is useful to let the user define a list of preference.

Definition at line 242 of file objectdescriptionmodel.h.

Member Data Documentation

◆ d

template<ObjectDescriptionType type>

ObjectDescriptionModelData* const Phonon::ObjectDescriptionModel< type >::d

protected

Definition at line 359 of file objectdescriptionmodel.h.

◆ staticMetaObject

template<ObjectDescriptionType type>

PHONON_TEMPLATE_CLASS_MEMBER_EXPORT const QMetaObject Phonon::ObjectDescriptionModel< type >::staticMetaObject

static

Definition at line 195 of file objectdescriptionmodel.h.

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

KDE's Doxygen guidelines are available online.

Class Picker

Quick Links

About Phonon

Phonon::ObjectDescriptionModel

Public Member Functions

Static Public Attributes

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ObjectDescriptionModel() [1/2]

◆ ObjectDescriptionModel() [2/2]

Member Function Documentation

◆ data()

◆ dropMimeData()

◆ flags()

◆ metaObject()

◆ mimeData()

◆ mimeTypes()

◆ modelData() [1/2]

◆ modelData() [2/2]

◆ moveDown()

◆ moveUp()

◆ qt_metacast()

◆ removeRows()

◆ rowCount()

◆ setModelData()

◆ staticMetaObject() [1/6]

◆ staticMetaObject() [2/6]

◆ staticMetaObject() [3/6]

◆ staticMetaObject() [4/6]

◆ staticMetaObject() [5/6]

◆ staticMetaObject() [6/6]

◆ supportedDropActions()

◆ tupleIndexAtPositionIndex()

◆ tupleIndexOrder()

Member Data Documentation

◆ d

◆ staticMetaObject