Qt 5.9 | Qt Multimedia | C++ Classes | QMediaService

Qt 5.9.4 Reference Documentation

# QMediaService Class

The QMediaService class provides a common base class for media service implementations. More...

Header: | #include <QMediaService>
qmake: | QT += multimedia

- List of all members, including inherited members

## Public Functions

| ~QMediaService()
virtual void | releaseControl(QMediaControl *control) = 0
virtual QMediaControl * | requestControl(const char *interface) = 0
T | requestControl()

## Protected Functions

| QMediaService(QObject *parent)

## Detailed Description

The QMediaService class provides a common base class for media service implementations.

Media services provide implementations of the functionality promised by media objects, and allow multiple providers to implement a QMediaObject.

To provide the functionality of a QMediaObject media services implement QMediaControl interfaces. Services typically implement one core media control which provides the core feature of a media object, and some number of additional controls which provide either optional features of the media object, or features of a secondary media object or peripheral object.

A pointer to media service's QMediaControl implementation can be obtained by passing the control's interface name to the requestControl() function.

      QMediaPlayerControl *control = qobject_cast<QMediaPlayerControl *>(
              mediaService->requestControl("org.qt-project.qt.mediaplayercontrol/5.0"));

Media objects can use services loaded dynamically from plug-ins or implemented statically within an applications. Plug-in based services should also implement the QMediaServiceProviderPlugin interface. Static services should implement the QMediaServiceProvider interface. In general, implementing a QMediaService is outside of the scope of this documentation and support on the relevant mailing lists or IRC channels should be sought.

See also QMediaObject and QMediaControl.

## Member Function Documentation

### `[protected]` QMediaService::QMediaService(QObject *parent)

Construct a media service with the given parent. This class is meant as a base class for Multimedia services so this constructor is protected.

### QMediaService::~QMediaService()

Destroys a media service.

### `[pure virtual]` void QMediaService::releaseControl(QMediaControl *control)

Releases a control back to the service.

### `[pure virtual]` QMediaControl *QMediaService::requestControl(const char *interface)

Returns a pointer to the media control implementing interface.

If the service does not implement the control, or if it is unavailable a null pointer is returned instead.

Controls must be returned to the service when no longer needed using the releaseControl() function.

### T QMediaService::requestControl()

Returns a pointer to the media control of type T implemented by a media service.

If the service does not implement the control, or if it is unavailable a null pointer is returned instead.

Controls must be returned to the service when no longer needed using the releaseControl() function.