QMetaDataReaderControl Class▲
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Header: QMetaDataReaderControl
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qmake: QT += multimedia
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Inherits: QMediaControl
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Inherited By:
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Group: QMetaDataReaderControl is part of multimedia_control
Detailed Description▲
If a QMediaService can provide read or write access to the meta-data of its current media it will implement QMetaDataReaderControl. This control provides functions for both retrieving and setting meta-data values. Meta-data may be addressed by the keys defined in the QMediaMetaData namespace.
The functionality provided by this control is exposed to application code by the meta-data members of QMediaObject, and so meta-data access is potentially available in any of the media object classes. Any media service may implement QMetaDataReaderControl.
The interface name of QMetaDataReaderControl is org.qt-project.qt.metadatareadercontrol/5.0 as defined in QMetaDataReaderControl_iid.
See Also▲
See also QMediaService::requestControl(), QMediaObject
Member Function Documentation▲
[explicit protected] QMetaDataReaderControl::QMetaDataReaderControl(QObject *parent = nullptr)▲
Construct a QMetaDataReaderControl with parent. This class is meant as a base class for service specific meta data providers so this constructor is protected.
[virtual] QMetaDataReaderControl::~QMetaDataReaderControl()▲
Destroy the meta-data object.
[pure virtual] QStringList QMetaDataReaderControl::availableMetaData() const▲
Returns a list of keys there is meta-data available for.
[pure virtual] bool QMetaDataReaderControl::isMetaDataAvailable() const▲
Identifies if meta-data is available from a media service.
Returns true if the meta-data is available and false otherwise.
[pure virtual] QVariant QMetaDataReaderControl::metaData(const QString &key) const▲
Returns the meta-data for the given key.
void QMetaDataReaderControl::metaDataAvailableChanged(bool available)▲
Signal the availability of meta-data has changed, available will be true if the multimedia object has meta-data.
void QMetaDataReaderControl::metaDataChanged()▲
Signal the changes of meta-data.
If multiple meta-data elements are changed, metaDataChanged(const QString &key, const QVariant &value) signal is emitted for each of them with metaDataChanged() changed emitted once.
void QMetaDataReaderControl::metaDataChanged(const QString &key, const QVariant &value)▲
Signal the changes of one meta-data element value with the given key.
Macro Documentation▲
QMetaDataReaderControl_iid▲
org.qt-project.qt.metadatareadercontrol/5.0
Defines the interface name of the QMetaDataReaderControl class.