Qt 5.7 | Qt Multimedia | C++ Classes | QCameraViewfinderSettingsControl

Qt 5.7.1 Reference Documentation

# QCameraViewfinderSettingsControl Class

The QCameraViewfinderSettingsControl class provides an abstract class for controlling camera viewfinder parameters. More...

Header: | #include <QCameraViewfinderSettingsControl>
qmake: | QT += multimedia
Inherits: | QMediaControl

- List of all members, including inherited members

## Public Types

enum | ViewfinderParameter { Resolution, PixelAspectRatio, MinimumFrameRate, MaximumFrameRate, PixelFormat, UserParameter }

## Public Functions

| ~QCameraViewfinderSettingsControl()
virtual bool | isViewfinderParameterSupported(ViewfinderParameter parameter) const = 0
virtual void | setViewfinderParameter(ViewfinderParameter parameter, const QVariant &value) = 0
virtual QVariant | viewfinderParameter(ViewfinderParameter parameter) const = 0

## Protected Functions

| QCameraViewfinderSettingsControl(QObject *parent = Q_NULLPTR)

## Macros

| QCameraViewfinderSettingsControl_iid

## Detailed Description

The QCameraViewfinderSettingsControl class provides an abstract class for controlling camera viewfinder parameters.

The interface name of QCameraViewfinderSettingsControl is `org.qt-project.qt.cameraviewfindersettingscontrol/5.0` as defined in QCameraViewfinderSettingsControl_iid.

Warning: New backends should implement QCameraViewfinderSettingsControl2 instead. Application developers should request this control only if QCameraViewfinderSettingsControl2 is not available.

See also QMediaService::requestControl(), QCameraViewfinderSettingsControl2, and QCamera.

## Member Type Documentation

### enum QCameraViewfinderSettingsControl::ViewfinderParameter

Constant | Value | Description
--- | --- | ---
`QCameraViewfinderSettingsControl::Resolution` | `0` | Viewfinder resolution, QSize.
`QCameraViewfinderSettingsControl::PixelAspectRatio` | `1` | Pixel aspect ratio, QSize as in QVideoSurfaceFormat::pixelAspectRatio
`QCameraViewfinderSettingsControl::MinimumFrameRate` | `2` | Minimum viewfinder frame rate, qreal
`QCameraViewfinderSettingsControl::MaximumFrameRate` | `3` | Maximum viewfinder frame rate, qreal
`QCameraViewfinderSettingsControl::PixelFormat` | `4` | Viewfinder pixel format, QVideoFrame::PixelFormat
`QCameraViewfinderSettingsControl::UserParameter` | `1000` | The base value for platform specific extended parameters. For such parameters the sequential values starting from UserParameter should be used.

## Member Function Documentation

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

Constructs a camera viewfinder control object with parent.

### QCameraViewfinderSettingsControl::~QCameraViewfinderSettingsControl()

Destroys the camera viewfinder control object.

### `[pure virtual]` bool QCameraViewfinderSettingsControl::isViewfinderParameterSupported(ViewfinderParameter parameter) const

Returns true if configuration of viewfinder parameter is supported by camera backend.

### `[pure virtual]` void QCameraViewfinderSettingsControl::setViewfinderParameter(ViewfinderParameter parameter, const QVariant &value)

Set the prefferred value of viewfinder parameter.

Calling this while the camera is active may result in the camera being stopped and reloaded. If video recording is in progress, this call may be ignored.

If an unsupported parameter is specified the camera may fail to load, or the setting may be ignored.

Viewfinder parameters may also depend on other camera settings, especially in video capture mode. If camera configuration conflicts with viewfinder settings, the camara configuration is usually preferred.

See also viewfinderParameter().

### `[pure virtual]` QVariant QCameraViewfinderSettingsControl::viewfinderParameter(ViewfinderParameter parameter) const

Returns the value of viewfinder parameter.

See also setViewfinderParameter().

## Macro Documentation

### QCameraViewfinderSettingsControl_iid

`org.qt-project.qt.cameraviewfindersettingscontrol/5.0`

Defines the interface name of the QCameraViewfinderSettingsControl class.