QCameraFeedbackControl Class

The QCameraFeedbackControl class allows controlling feedback (sounds etc) during camera operation. More...

Header: #include <QCameraFeedbackControl>
qmake: QT += multimedia
Since: Qt 5.0
Inherits: QMediaControl

This class is obsolete. It is provided to keep old source code working. We strongly advise against using it in new code.

This class was introduced in Qt 5.0.

Public Types

enum EventType { ViewfinderStarted, ViewfinderStopped, ImageCaptured, ImageSaved, ImageError, …, AutoFocusFailed }

Public Functions

virtual ~QCameraFeedbackControl()
virtual bool isEventFeedbackEnabled(QCameraFeedbackControl::EventType event) const = 0
virtual bool isEventFeedbackLocked(QCameraFeedbackControl::EventType event) const = 0
virtual void resetEventFeedback(QCameraFeedbackControl::EventType event) = 0
virtual bool setEventFeedbackEnabled(QCameraFeedbackControl::EventType event, bool enabled) = 0
virtual bool setEventFeedbackSound(QCameraFeedbackControl::EventType event, const QString &filePath) = 0

Protected Functions

QCameraFeedbackControl(QObject *parent = nullptr)


Detailed Description

When using a camera, there are several times when some form of feedback to the user is given - for example, when an image is taken, or when recording is started. You can enable or disable some of this feedback, or adjust what sound might be played for these actions.

In some cases it may be undesirable to play a sound effect - for example, when initiating video recording the sound itself may be recorded.

Note: In some countries or regions, feedback sounds or other indications (e.g. a red light) are mandatory during camera operation. In these cases, you can check isEventFeedbackLocked to check if that type of feedback can be modified. Any attempts to change a locked feedback type will be ignored.

The interface name of QCameraFeedbackControl is org.qt-project.qt.camerafeedbackcontrol/5.0 as defined in QCameraFeedbackControl_iid.

See also QCamera.

Member Type Documentation

enum QCameraFeedbackControl::EventType

This enumeration describes certain events that occur during camera usage. You can associate some form of feedback to be given when the event occurs, or check whether feedback for this event is enabled or locked so that changes cannot be made.

QCameraFeedbackControl::ViewfinderStarted1The viewfinder stream was started (even if not visible)
QCameraFeedbackControl::ViewfinderStopped2The viewfinder stream was stopped
QCameraFeedbackControl::ImageCaptured3An image was captured but not yet fully processed
QCameraFeedbackControl::ImageSaved4An image is fully available and saved somewhere.
QCameraFeedbackControl::ImageError5An error occurred while capturing an image
QCameraFeedbackControl::RecordingStarted6Video recording has started
QCameraFeedbackControl::RecordingInProgress7Video recording is in progress
QCameraFeedbackControl::RecordingStopped8Video recording has stopped
QCameraFeedbackControl::AutoFocusInProgress9The camera is trying to automatically focus
QCameraFeedbackControl::AutoFocusLocked10The camera has automatically focused successfully
QCameraFeedbackControl::AutoFocusFailed11The camera was unable to focus automatically

Member Function Documentation

[protected] QCameraFeedbackControl::QCameraFeedbackControl(QObject *parent = nullptr)

Constructs a camera feedback control object with parent.

[virtual] QCameraFeedbackControl::~QCameraFeedbackControl()

Destroys the camera feedback control object.

[pure virtual] bool QCameraFeedbackControl::isEventFeedbackEnabled(QCameraFeedbackControl::EventType event) const

Returns true if the feedback for event is enabled.

This function was introduced in Qt 5.0.

[pure virtual] bool QCameraFeedbackControl::isEventFeedbackLocked(QCameraFeedbackControl::EventType event) const

Returns true if the feedback setting for event is locked. This may be true because of legal compliance issues, or because configurability of this event's feedback is not supported.

This function was introduced in Qt 5.0.

[pure virtual] void QCameraFeedbackControl::resetEventFeedback(QCameraFeedbackControl::EventType event)

Restores the feedback setting for this event to its default setting.

This function was introduced in Qt 5.0.

[pure virtual] bool QCameraFeedbackControl::setEventFeedbackEnabled(QCameraFeedbackControl::EventType event, bool enabled)

Turns on feedback for the specific event if enabled is true, otherwise disables the feedback. Returns true if the feedback could be modified, or false otherwise (e.g. this feedback type is locked).

This function was introduced in Qt 5.0.

See also isEventFeedbackEnabled().

[pure virtual] bool QCameraFeedbackControl::setEventFeedbackSound(QCameraFeedbackControl::EventType event, const QString &filePath)

When the given event occurs, the sound effect referenced by filePath will be played instead of the default sound.

If this feedback type is locked, or if the supplied path is inaccessible, this function will return false. In addition, some forms of feedback may be non-auditory (e.g. a red light, or a vibration), and false may be returned in this case.

The file referenced should be linear PCM (WAV format).

Note: In the case that a valid file path to an unsupported file is given, this function will return true but the feedback will use the original setting.

This function was introduced in Qt 5.0.

Macro Documentation



Defines the interface name of the QCameraFeedbackControl class.

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