Qt 5.9 | Qt Multimedia | C++ Classes | QMediaControl

Qt 5.9.4 Reference Documentation

# QMediaControl Class

The QMediaControl class provides a base interface for media service controls. More...

Header: | #include <QMediaControl>
qmake: | QT += multimedia
Inherited By: | QAudioDecoderControl, QAudioEncoderSettingsControl, QAudioInputSelectorControl, QAudioOutputSelectorControl, QAudioRoleControl, QCameraCaptureBufferFormatControl, QCameraCaptureDestinationControl, QCameraControl, QCameraExposureControl, QCameraFeedbackControl, QCameraFlashControl, QCameraFocusControl, QCameraImageCaptureControl, QCameraImageProcessingControl, QCameraInfoControl, QCameraLocksControl, QCameraViewfinderSettingsControl, QCameraViewfinderSettingsControl2, QCameraZoomControl, QImageEncoderControl, QMediaAudioProbeControl, QMediaAvailabilityControl, QMediaContainerControl, QMediaGaplessPlaybackControl, QMediaNetworkAccessControl, QMediaPlayerControl, QMediaRecorderControl, QMediaStreamsControl, QMediaVideoProbeControl, QMetaDataReaderControl, QMetaDataWriterControl, QRadioDataControl, QRadioTunerControl, QVideoDeviceSelectorControl, QVideoEncoderSettingsControl, QVideoRendererControl, QVideoWidgetControl, and QVideoWindowControl

- List of all members, including inherited members

## Public Functions

| ~QMediaControl()

## Protected Functions

| QMediaControl(QObject *parent = Q_NULLPTR)

## Macros

| Q_MEDIA_DECLARE_CONTROL(Class, IId)

## Detailed Description

The QMediaControl class provides a base interface for media service controls.

Media controls provide an interface to individual features provided by a media service. Most services implement a principal control which exposes the core functionality of the service and a number of optional controls which expose any additional functionality.

A pointer to a control implemented by a media service can be obtained using the QMediaService::requestControl() member of QMediaService. If the service doesn't implement a control it will instead return a null pointer.

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

Alternatively if the IId of the control has been declared using Q_MEDIA_DECLARE_CONTROL the template version of QMediaService::requestControl() can be used to request the service without explicitly passing the IId or using qobject_cast().

      QMediaPlayerControl *control = mediaService->requestControl<QMediaPlayerControl *>();

Most application code will not interface directly with a media service's controls, instead the QMediaObject which owns the service acts as an intermediary between one or more controls and the application.

See also QMediaService and QMediaObject.

## Member Function Documentation

### `[protected]` QMediaControl::QMediaControl(QObject *parent = Q_NULLPTR)

Constructs a media control with the given parent.

### QMediaControl::~QMediaControl()

Destroys a media control.

## Macro Documentation

### Q_MEDIA_DECLARE_CONTROL(Class, IId)

The Q_MEDIA_DECLARE_CONTROL macro declares an IId for a Class that inherits from QMediaControl.

Declaring an IId for a QMediaControl allows an instance of that control to be requested from QMediaService::requestControl() without explicitly passing the IId.

      QMediaPlayerControl *control = mediaService->requestControl<QMediaPlayerControl *>();

See also QMediaService::requestControl().