- Qt 6.8
- Qt Core
- C++ Classes
- QPermission
- Qt 6.8.3 Reference Documentation

# QPermission Class

An opaque wrapper of a typed permission. More...

Header: | `#include <QPermissions>`
CMake: | `find_package(Qt6 REQUIRED COMPONENTS Core)` `target_link_libraries(mytarget PRIVATE Qt6::Core)`
qmake: | `QT += core`
Since: | Qt 6.5

- List of all members, including inherited members

## Public Functions

| QPermission(const T &type)
Qt::PermissionStatus | status() const
QMetaType | type() const
std::optional<T> | value() const

## Detailed Description

The QPermission class is an opaque wrapper of a typed permission, used when checking or requesting permissions. You do not need to construct this type explicitly, as the type is automatically used when checking or requesting permissions:

     qApp->checkPermission(QCameraPermission{});

When requesting permissions, the given functor will be passed an instance of a QPermission, which can be used to check the result of the request:

     qApp->requestPermission(QCameraPermission{}, [](const QPermission &permission) {
         if (permission.status() == Qt::PermissionStatus::Granted)
             takePhoto();
     });

To inspect the properties of the original, typed permission, use the value() function:

     QLocationPermission locationPermission;
     locationPermission.setAccuracy(QLocationPermission::Precise);
     qApp->requestPermission(locationPermission, this, &LocationWidget::permissionUpdated);

     void LocationWidget::permissionUpdated(const QPermission &permission)
     {
         if (permission.status() != Qt::PermissionStatus::Granted)
             return;
         auto locationPermission = permission.value<QLocationPermission>();
         if (!locationPermission || locationPermission->accuracy() != QLocationPermission::Precise)
             return;
         updatePreciseLocation();
     }

#### Typed Permissions

The following permissions are available:

QBluetoothPermission | Access Bluetooth peripherals
QCalendarPermission | Access the user's calendar
QCameraPermission | Access the camera for taking pictures or videos
QContactsPermission | Access the user's contacts
QLocationPermission | Access the user's location
QMicrophonePermission | Access the microphone for monitoring or recording sound

See also Application Permissions.

## Member Function Documentation

### template <typename T, QPermission::if_permission<T> = true> QPermission::QPermission(const T &type)

Constructs a permission from the given typed permission type.

You do not need to construct this type explicitly, as the type is automatically used when checking or requesting permissions.

This constructor participates in overload resolution only if `T` is one of the typed permission classes:

QBluetoothPermission | Access Bluetooth peripherals
QCalendarPermission | Access the user's calendar
QCameraPermission | Access the camera for taking pictures or videos
QContactsPermission | Access the user's contacts
QLocationPermission | Access the user's location
QMicrophonePermission | Access the microphone for monitoring or recording sound

### Qt::PermissionStatus QPermission::status() const

Returns the status of the permission.

### QMetaType QPermission::type() const

Returns the type of the permission.

### template <typename T, QPermission::if_permission<T> = true> std::optional<T> QPermission::value() const

Returns the typed permission of type `T`, or `std::nullopt` if this QPermission object doesn't contain one.

Use type() for dynamically choosing which typed permission to request.

This function participates in overload resolution only if `T` is one of the typed permission classes:

QBluetoothPermission | Access Bluetooth peripherals
QCalendarPermission | Access the user's calendar
QCameraPermission | Access the camera for taking pictures or videos
QContactsPermission | Access the user's contacts
QLocationPermission | Access the user's location
QMicrophonePermission | Access the microphone for monitoring or recording sound