QInputDevice Class

The QInputDevice class describes a device from which a QInputEvent originates. More...

Header:	#include <QInputDevice>
CMake:	find_package(Qt6 COMPONENTS Gui REQUIRED) target_link_libraries(mytarget PRIVATE Qt6::Gui)
qmake:	QT += gui
Since:	Qt 6.0
Inherits:	QObject
Inherited By:	QPointingDevice

• List of all members, including inherited members

Public Types

flags	Capabilities
enum class	Capability { None, Position, Area, Pressure, Velocity, …, All }
enum class	DeviceType { Unknown, Mouse, TouchScreen, TouchPad, Stylus, …, AllDevices }
flags	DeviceTypes

Public Functions

	QInputDevice(const QString &name, qint64 id, QInputDevice::DeviceType type, const QString &seatName = QString(), QObject *parent = nullptr)
	QInputDevice(QObject *parent = nullptr)
QRect	availableVirtualGeometry() const
QInputDevice::Capabilities	capabilities() const
bool	hasCapability(QInputDevice::Capability capability) const
QString	name() const
QString	seatName() const
qint64	systemId() const
QInputDevice::DeviceType	type() const

Signals

void	availableVirtualGeometryChanged(QRect area)

Static Public Members

QList<const QInputDevice *>	devices()
const QInputDevice *	primaryKeyboard(const QString &seatName = QString())

Detailed Description

Each QInputEvent contains a QInputDevice pointer to allow accessing device-specific properties like type, capabilities and seat. It is the responsibility of the platform or generic plug-ins to discover, create and register an instance of this class corresponding to each available input device, via QWindowSystemInterface::registerInputDevice(), before generating any input event referring to that device.

Applications do not need to instantiate this class, but can read the instances pointed to by QInputEvent::device() and QInputDevice::devices().

Member Type Documentation

[since 6.2] enum class QInputDevice::Capabilityflags QInputDevice::Capabilities

Indicates what kind of information the input device or its driver can provide.

Constant	Value	Description
QInputDevice::Capability::None	0	No information about input device capabilities available.
QInputDevice::Capability::Position	0x0001	Indicates that position information is available, meaning that the position() family of functions in the touch points return valid points.
QInputDevice::Capability::Area	0x0002	Indicates that touch area information is available, meaning that QEventPoint::ellipseDiameters() in the touch points return valid values.
QInputDevice::Capability::Pressure	0x0004	Indicates that pressure information is available, meaning that QEventPoint::pressure() returns a valid value.
QInputDevice::Capability::Velocity	0x0008	Indicates that velocity information is available, meaning that QEventPoint::velocity() returns a valid vector.
QInputDevice::Capability::NormalizedPosition	0x0020	Indicates that the normalized position is available, meaning that QEventPoint::globalPosition() returns a valid value.
QInputDevice::Capability::MouseEmulation	0x0040	Indicates that the device synthesizes mouse events.
QInputDevice::Capability::Scroll	0x0100	Indicates that the device has a scroll capability.
QInputDevice::Capability::PixelScroll	0x0080	Indicates that the device (usually a touchpad) scrolls with pixel precision.
QInputDevice::Capability::Hover	0x0200	Indicates that the device has a hover capability.
QInputDevice::Capability::Rotation	0x0400	Indicates that rotation information is available.
QInputDevice::Capability::XTilt	0x0800	Indicates that tilt information is available for the X-axis.
QInputDevice::Capability::YTilt	0x1000	Indicates that tilt information is available for the Y-axis.
QInputDevice::Capability::TangentialPressure	0x2000	Indicates that tangential pressure information is available.
QInputDevice::Capability::ZPosition	0x4000	Indicates that position information for the Z-axis is available.
QInputDevice::Capability::All	0x7FFFFFFF

This enum was introduced or modified in Qt 6.2.

The Capabilities type is a typedef for QFlags<Capability>. It stores an OR combination of Capability values.

enum class QInputDevice::DeviceTypeflags QInputDevice::DeviceTypes

This enum represents the type of device that generated a QPointerEvent.

Constant	Value	Description
QInputDevice::DeviceType::Unknown	0x0000	The device cannot be identified.
QInputDevice::DeviceType::Mouse	0x0001	A mouse.
QInputDevice::DeviceType::TouchScreen	0x0002	In this type of device, the touch surface and display are integrated. This means the surface and display typically have the same size, such that there is a direct relationship between the touch points' physical positions and the coordinate reported by QEventPoint. As a result, Qt allows the user to interact directly with multiple QWidgets, QGraphicsItems, or Qt Quick Items at the same time.
QInputDevice::DeviceType::TouchPad	0x0004	In this type of device, the touch surface is separate from the display. There is not a direct relationship between the physical touch location and the on-screen coordinates. Instead, they are calculated relative to the current mouse position, and the user must use the touch-pad to move this reference point. Unlike touch-screens, Qt allows users to only interact with a single QWidget or QGraphicsItem at a time.
QInputDevice::DeviceType::Stylus	0x0010	A pen-like device used on a graphics tablet such as a Wacom tablet, or on a touchscreen that provides a separate stylus sensing capability.
QInputDevice::DeviceType::Airbrush	0x0020	A stylus with a thumbwheel to adjust tangentialPressure.
QInputDevice::DeviceType::Puck	0x0008	A device that is similar to a flat mouse with a transparent circle with cross-hairs.
QInputDevice::DeviceType::Keyboard	0x1000	A keyboard.
QInputDevice::DeviceType::AllDevices	0x7FFFFFFF	Any of the above (used as a default filter value).

The DeviceTypes type is a typedef for QFlags<DeviceType>. It stores an OR combination of DeviceType values.

Member Function Documentation

QInputDevice::QInputDevice(const QString &name, qint64 id, QInputDevice::DeviceType type, const QString &seatName = QString(), QObject *parent = nullptr)

Creates a new input device instance. The given name is normally a manufacturer-assigned model name if available, or something else identifiable; id is a platform-specific number that will be unique per device (for example the xinput ID on X11); type identifies what kind of device. On window systems that are capable of handling input from multiple users or sets of input devices at the same time (such as Wayland or X11), seatName identifies the name of the set of devices that will be used together. If the device is a child or slave device (for example one of several mice that can take turns moving the "core pointer"), the master device should be given as the parent.

The platform plugin creates, registers and continues to own each device instance; usually parent should be given for memory management purposes even if there is no master for a particular device.

By default, capabilities() are None.

QInputDevice::QInputDevice(QObject *parent = nullptr)

Creates a new invalid input device instance as a child of parent.

QRect QInputDevice::availableVirtualGeometry() const

Returns the region within the virtual desktop that this device can access.

For example a TouchScreen input device is fixed in place upon a single physical screen, and usually calibrated so that this area is the same as QScreen::geometry(); whereas a Mouse can probably access all screens on the virtual desktop. A Wacom graphics tablet may be configured in a way that it's mapped to all screens, or only to the screen where the user prefers to create drawings, or to the window in which drawing occurs. A Stylus device that is integrated with a touchscreen may be physically limited to that screen.

If the returned rectangle is null, it means this device can access the entire virtual desktop.

Note: Getter function for property availableVirtualGeometry.

QInputDevice::Capabilities QInputDevice::capabilities() const

Returns the device capabilities.

Note: Getter function for property capabilities.

[static] QList<const QInputDevice *> QInputDevice::devices()

Returns a list of all registered input devices (keyboards and pointing devices).

bool QInputDevice::hasCapability(QInputDevice::Capability capability) const

Returns whether the device capabilities include the given capability.

QString QInputDevice::name() const

Returns the device name.

This string may be empty. It is however useful on systems that have multiple input devices: it can be used to differentiate from which device a QPointerEvent originates.

Note: Getter function for property name.

[static] const QInputDevice *QInputDevice::primaryKeyboard(const QString &seatName = QString())

Returns the core or master keyboard on the given seat seatName.

QString QInputDevice::seatName() const

Returns the seat with which the device is associated, if known; otherwise empty.

Devices that are intended to be used together by one user may be configured to have the same seat name. That is only possible on Wayland and X11 platforms so far.

Note: Getter function for property seatName.

qint64 QInputDevice::systemId() const

Returns the platform specific system ID (for example xinput ID on the X11 platform).

All platforms are expected to provide a unique system ID for each device.

Note: Getter function for property systemId.

QInputDevice::DeviceType QInputDevice::type() const

Returns the device type.

Note: Getter function for property type.