path: root/src/multimedia/camera/qcamerainfo.cpp

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#include "qcamerainfo.h"

#include "qcamera_p.h"
#include "qmediaserviceprovider_p.h"

#include <qvideodeviceselectorcontrol.h>
#include <qcamerainfocontrol.h>

QT_BEGIN_NAMESPACE

/*!
    \class QCameraInfo
    \brief The QCameraInfo class provides general information about camera devices.
    \since 5.3
    \inmodule QtMultimedia
    \ingroup multimedia
    \ingroup multimedia_camera

    QCameraInfo lets you query for camera devices that are currently available on the system.

    The static functions defaultCamera() and availableCameras() provide you a list of all
    available cameras.

    This example prints the name of all available cameras:

    \snippet multimedia-snippets/camera.cpp Camera listing

    A QCameraInfo can be used to construct a QCamera. The following example instantiates a QCamera
    whose camera device is named 'mycamera':

    \snippet multimedia-snippets/camera.cpp Camera selection

    You can also use QCameraInfo to get general information about a camera device such as
    description, physical position on the system, or camera sensor orientation.

    \snippet multimedia-snippets/camera.cpp Camera info

    \sa QCamera
*/

class QCameraInfoPrivate
{
public:
    QCameraInfoPrivate() : isNull(true), position(QCamera::UnspecifiedPosition), orientation(0)
    { }

    bool isNull;
    QString deviceName;
    QString description;
    QCamera::Position position;
    int orientation;
};

/*!
    Constructs a camera info object for \a camera.

    You can use it to query information about the \a camera object passed as argument.

    If the \a camera is invalid, for example when no camera device is available on the system,
    the QCameraInfo object will be invalid and isNull() will return true.
*/
QCameraInfo::QCameraInfo(const QCamera &camera)
    : d(new QCameraInfoPrivate)
{
    const QVideoDeviceSelectorControl *deviceControl = camera.d_func()->deviceControl;
    if (deviceControl && deviceControl->deviceCount() > 0) {
        const int selectedDevice = deviceControl->selectedDevice();
        d->deviceName = deviceControl->deviceName(selectedDevice);
        d->description = deviceControl->deviceDescription(selectedDevice);
        d->isNull = false;
    }

    const QCameraInfoControl *infoControl = camera.d_func()->infoControl;
    if (infoControl) {
        d->position = infoControl->cameraPosition(d->deviceName);
        d->orientation = infoControl->cameraOrientation(d->deviceName);
        d->isNull = false;
    }
}

/*!
    Constructs a camera info object from a camera device \a name.

    If no such device exists, the QCameraInfo object will be invalid and isNull() will return true.
*/
QCameraInfo::QCameraInfo(const QByteArray &name)
    : d(new QCameraInfoPrivate)
{
    if (!name.isNull()) {
        QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
        const QByteArray service(Q_MEDIASERVICE_CAMERA);
        if (provider->devices(service).contains(name)) {
            d->deviceName = QString::fromLatin1(name);
            d->description = provider->deviceDescription(service, name);
            d->position = provider->cameraPosition(name);
            d->orientation = provider->cameraOrientation(name);
            d->isNull = false;
        }
    }
}

/*!
    Constructs a copy of \a other.
*/
QCameraInfo::QCameraInfo(const QCameraInfo &other)
    : d(other.d)
{
}

/*!
    Destroys the QCameraInfo.
*/
QCameraInfo::~QCameraInfo()
{
}

/*!
    Returns true if this QCameraInfo is equal to \a other.
*/
bool QCameraInfo::operator==(const QCameraInfo &other) const
{
    if (d == other.d)
        return true;

    return (d->deviceName == other.d->deviceName
            && d->description == other.d->description
            && d->position == other.d->position
            && d->orientation == other.d->orientation);
}

/*!
    Returns true if this QCameraInfo is null or invalid.
*/
bool QCameraInfo::isNull() const
{
    return d->isNull;
}

/*!
    Returns the device name of the camera

    This is a unique ID to identify the camera and may not be human-readable.
*/
QString QCameraInfo::deviceName() const
{
    return d->deviceName;
}

/*!
    Returns the human-readable description of the camera.
*/
QString QCameraInfo::description() const
{
    return d->description;
}

/*!
    Returns the physical position of the camera on the hardware system.
*/
QCamera::Position QCameraInfo::position() const
{
    return d->position;
}

/*!
    Returns the physical orientation of the camera sensor.

    The value is the orientation angle (clockwise, in steps of 90 degrees) of the camera sensor
    in relation to the display in its natural orientation.

    You can show the camera image in the correct orientation by rotating it by this value in the
    anti-clockwise direction.

    For example, suppose a mobile device which is naturally in portrait orientation. The back-facing
    camera is mounted in landscape. If the top side of the camera sensor is aligned with the
    right edge of the screen in natural orientation, the value should be 270. If the top side of a
    front-facing camera sensor is aligned with the right of the screen, the value should be 90.
*/
int QCameraInfo::orientation() const
{
    return d->orientation;
}

/*!
    Returns the default camera on the system.

    The returned object should be checked using isNull() before being used, in case there is no
    default camera or no cameras at all.

    \sa availableCameras()
*/
QCameraInfo QCameraInfo::defaultCamera()
{
    return QCameraInfo(QMediaServiceProvider::defaultServiceProvider()->defaultDevice(Q_MEDIASERVICE_CAMERA));
}

/*!
    Returns a list of available cameras on the system which are located at \a position.

    If \a position is not specified or if the value is QCamera::UnspecifiedPosition, a list of
    all available cameras will be returned.
*/
QList<QCameraInfo> QCameraInfo::availableCameras(QCamera::Position position)
{
    QList<QCameraInfo> cameras;

    const QMediaServiceProvider *provider = QMediaServiceProvider::defaultServiceProvider();
    const QByteArray service(Q_MEDIASERVICE_CAMERA);
    const QList<QByteArray> devices = provider->devices(service);
    for (int i = 0; i < devices.count(); ++i) {
        const QByteArray &name = devices.at(i);
        if (position == QCamera::UnspecifiedPosition
                || position == provider->cameraPosition(name)) {
            cameras.append(QCameraInfo(name));
        }
    }

    return cameras;
}

/*!
    Sets the QCameraInfo object to be equal to \a other.
*/
QCameraInfo& QCameraInfo::operator=(const QCameraInfo& other)
{
    d = other.d;
    return *this;
}

/*!
    \fn QCameraInfo::operator!=(const QCameraInfo &other) const

    Returns true if this QCameraInfo is different from \a other.
*/

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug d, const QCameraInfo &camera)
{
    d.maybeSpace() << QStringLiteral("QCameraInfo(deviceName=%1, position=%2, orientation=%3)")
                          .arg(camera.deviceName())
                          .arg(QString::fromLatin1(QCamera::staticMetaObject.enumerator(QCamera::staticMetaObject.indexOfEnumerator("Position"))
                               .valueToKey(camera.position())))
                          .arg(camera.orientation());
    return d.space();
}
#endif

QT_END_NAMESPACE