qmlpermissions.qdoc

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// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
 
/*!
    \page qml-application-permissions.html
    \title QML Application Permissions
    \brief Managing application permissions via QML
 
    Many features of today's devices and operating systems can have
    significant privacy, security, and performance implications if
    misused. It's therefore increasingly common for platforms to
    require explicit consent from the user before accessing these
    features.
 
    The \l{Qt Qml Core} module exposes the Qt C++
    \l [QtCore] {Application Permissions} functionality to QML via a set of
    permission types that can be used to check or request permission in a cross
    platform manner.
 
    \annotatedlist qml-permissions
 
    \note The available permission types cover core functionality of Qt modules
    like Qt Multimedia and Qt Positioning, but do not encompass all platform-specific
    permissions. Custom permission types are not currently supported.
 
    \section1 Usage
 
    To check and request a specific permission in your application,
    include an instance of the appropriate permission type, and set
    any of its properties if needed:
 
    \qml
        CalendarPermission {
            id: calendarPermission
            accessMode: CalendarPermission.ReadWrite
        }
    \endqml
 
    The type can be used to check the current state of the
    permissions, for example to drive a state based UI:
 
    \qml
        states: [
            State {
                name: "waitingForPermission"
                when: calendarPermission.status == Qt.PermissionStatus.Undetermined
                PropertyChanges { target: permissionRequestItem; visible: true }
            },
            State {
                name: "permissionDenied"
                when: calendarPermission.status == Qt.PermissionStatus.Denied
                PropertyChanges { target: permissionDeniedItem; visible: true }
            }
        ]
    \endqml
 
    In the example above, two permission specific items will be overlaid if the
    permission status is not granted. The request UI could perhaps look like:
 
    \qml
        Rectangle {
            id: permissionRequestItem
            anchors.fill: parent
            visible: false
 
            Text {
                anchors.centerIn: parent
                text: qsTr("We need your permission to access the calendar."
                    + "Please tap this screen to request permission.")
 
            }
 
            MouseArea {
                anchors.fill: parent
                onClicked: calendarPermission.request()
            }
        }
    \endqml
 
    With a corresponding denied UI:
 
    \qml
        Rectangle {
            id: permissionDeniedItem
            anchors.fill: parent
            color: "red"
            visible: false
            Text {
                anchors.centerIn: parent
                text: qsTr("We need your permission to access the calendar,"
                    + "but permission was not granted. Please resolve.")
            }
        }
    \endqml
 
    \section2 Changing permission properties
 
    The properties of a permission can be changed, even after
    a request has been initiated by calling `request()`. This
    will update the status, if it changes a result of the new
    property values, but will not result in an automatic request
    using the new set of properties.
 
    For example, if upgrading an already granted calendar permission
    for access mode \c Qt.CalendarPermission.ReadOnly to
    \c Qt.CalendarPermission.ReadWrite, the platform will
    respond in one of three ways:
 
        \list
        \li By implicitly granting the extended permission, for example
            because the platform doesn't distinguish between the two
            access modes, which will result in no state change.
        \li By moving the status back to \ Undetermined, so that
            the user can be consulted again for access to the now
            extended permission.
        \li By moving the status to \c Denied, for example if permissions
            can not be upgraded once initially requested.
        \endlist
 
    All these states should then move the application's UI into
    the appropriate state, where the user is informed of the
    new state, with the possibility of requesting the new
    permission if possible, or reverting to a less extensive
    permission.
 
    \section2 Interaction between permission items
 
    Although the permission state is ultimately tied to the
    underlying application, each permission item reports its own
    status independently of all other items, and needs to be
    independently requested if needed.
 
    For example, requesting calendar access for one item will
    not update the status of another CalendarPermission item,
    even if these have the exact same properties.
*/
 
/*!
    \include qmlpermissions.qdocinc {type-docs} {CalendarPermission} {QCalendarPermission} {calendar}
    \since 6.6
*/
/*!
    \include qmlpermissions.qdocinc {status-docs} {CalendarPermission}
*/
/*!
    \include qmlpermissions.qdocinc {request-docs} {CalendarPermission}
*/
/*!
    \include qmlpermissions.qdocinc {type-docs} {ContactsPermission} {QContactsPermission} {contacts}
    \since 6.6
*/
/*!
    \include qmlpermissions.qdocinc {status-docs} {ContactsPermission}
*/
/*!
    \include qmlpermissions.qdocinc {request-docs} {ContactsPermission}
*/
/*!
    \include qmlpermissions.qdocinc {type-docs} {CameraPermission} {QCameraPermission} {camera}
    \since 6.6
*/
/*!
    \include qmlpermissions.qdocinc {status-docs} {CameraPermission}
*/
/*!
    \include qmlpermissions.qdocinc {request-docs} {CameraPermission}
*/
/*!
    \include qmlpermissions.qdocinc {type-docs} {MicrophonePermission} {QMicrophonePermission} {microphone}
    \since 6.6
*/
/*!
    \include qmlpermissions.qdocinc {status-docs} {MicrophonePermission}
*/
/*!
    \include qmlpermissions.qdocinc {request-docs} {MicrophonePermission}
*/
/*!
    \include qmlpermissions.qdocinc {type-docs} {BluetoothPermission} {QBluetoothPermission} {Bluetooth peripherals}
    \since 6.6
*/
/*!
    \include qmlpermissions.qdocinc {status-docs} {BluetoothPermission}
*/
/*!
    \include qmlpermissions.qdocinc {request-docs} {BluetoothPermission}
*/
/*!
    \include qmlpermissions.qdocinc {type-docs} {LocationPermission} {QLocationPermission} {location}
    \since 6.6
*/
/*!
    \include qmlpermissions.qdocinc {status-docs} {LocationPermission}
*/
/*!
    \include qmlpermissions.qdocinc {request-docs} {LocationPermission}
*/