QCameraFocus *focus = camera->focus();
focus->setFocusPointMode(QCameraFocus::FocusPointCustom);
focus->setCustomFocusPoint(QPointF(0.25f, 0.75f)); // A point near the bottom left, 25% away from the corner, near that shiny vase

focus->zoomTo(3.0, 4.0); // Super zoom!

focus->setFocusPointMode(QCameraFocus::FocusPointAuto);
const QList<QCameraFocusZone> zones = focus->focusZones();
for (const QCameraFocusZone &zone : zones) {
    if (zone.status() == QCameraFocusZone::Focused) {
        // Draw a green box at zone.area()
    } else if (zone.status() == QCameraFocusZone::Selected) {
        // This area is selected for autofocusing, but is not in focus
        // Draw a yellow box at zone.area()
    }
}

Member Function Documentation

[signal] void QCameraFocus::digitalZoomChanged(qreal value)

Signal emitted when digital zoom value changes to new value.

Note: Notifier signal for property digitalZoom.

[signal] void QCameraFocus::focusZonesChanged()

This signal is emitted when the set of zones used in autofocusing is changed.

This can change when a zone is focused or loses focus, or new focus zones have been detected.

Note: Notifier signal for property focusZones.

[signal] void QCameraFocus::maximumDigitalZoomChanged(qreal zoom)

Signal emitted when the maximum supported digital zoom value changed.

The maximum supported zoom value can depend on other camera settings, like capture mode or resolution.

[signal] void QCameraFocus::maximumOpticalZoomChanged(qreal zoom)

Signal emitted when the maximum supported optical zoom value changed.

[signal] void QCameraFocus::opticalZoomChanged(qreal value)

Signal emitted when optical zoom value changes to new value.

Note: Notifier signal for property opticalZoom.

[virtual protected] QCameraFocus::~QCameraFocus()

Destroys the camera focus object.

bool QCameraFocus::isAvailable() const

Returns true if focus related settings are supported by this camera.

You may need to also check if any specific features are supported.

bool QCameraFocus::isFocusModeSupported(QCameraFocus::FocusModes mode) const

Returns true if the focus mode is supported by camera.

bool QCameraFocus::isFocusPointModeSupported(QCameraFocus::FocusPointMode mode) const

Returns true if focus point mode is supported.

qreal QCameraFocus::maximumDigitalZoom() const

Returns the maximum digital zoom

This will be 1.0 on cameras that do not support digital zoom.

qreal QCameraFocus::maximumOpticalZoom() const

Returns the maximum optical zoom.

This will be 1.0 on cameras that do not support optical zoom.

void QCameraFocus::zoomTo(qreal optical, qreal digital)

Set the camera optical and digital zoom values.

Since there may be a physical component to move, the change in zoom value may not be instantaneous.