LSeat Class Reference

Group of input and output devices. More...

Inheritance diagram for LSeat:

Classes
struct	OutputConfiguration
	Configuration parameters for an output. More...

Public Member Functions
	LSeat (const void *params)
	Constructor of the LSeat class. More...
	~LSeat ()
	Destructor of the LSeat class. More...
const std::vector< LGPU * > &	gpus () const noexcept
	Retrieves the available GPUs. More...
const std::vector< LOutput * > &	outputs () const noexcept
	Vector of available outputs. More...
const std::vector< LInputDevice * > &	inputDevices () const noexcept
	Vector of available input devices. More...
const std::vector< LSurface * > &	idleInhibitorSurfaces () const noexcept
	Surfaces requesting to inhibit the idle state. More...
const std::vector< const LIdleListener * > &	idleListeners () const noexcept
	Listeners used by clients to detect when the user has been idle for a specified amount of time. More...
void	setIsUserIdleHint (bool isIdle) noexcept
	Sets a hint about the user's idle state. More...
bool	isUserIdleHint () const noexcept
	Hint about the user's idle state set with setIsUserIdleHint(). More...
const char *	name () const noexcept
	The seat name. More...
LToplevelRole *	activeToplevel () const noexcept
	Active toplevel surface. More...
const std::vector< LToplevelResizeSession * > &	toplevelResizeSessions () const noexcept
	Active LToplevelRole resize sessions. More...
const std::vector< LToplevelMoveSession * > &	toplevelMoveSessions () const noexcept
	Active LToplevelRole move sessions. More...
LPointer *	pointer () const noexcept
	Access to pointer events. More...
LKeyboard *	keyboard () const noexcept
	Access to keyboard events. More...
LTouch *	touch () const noexcept
	Access to touch events. More...
LDND *	dnd () const noexcept
	Access to the drag & drop session manager. More...
LClipboard *	clipboard () const noexcept
	Access to the clipboard manager. More...
void	dismissPopups () noexcept
	Close all popups. More...
LPopupRole *	topmostPopup () const noexcept
	Retrieve the topmost popup role. More...
Public Member Functions inherited from LFactoryObject
Type	factoryObjectType () const noexcept
	Gets the base factory object type. More...
Public Member Functions inherited from LObject
	LObject (const LObject &) noexcept
	Copy constructor. More...
LObject &	operator= (const LObject &) noexcept
	Assignment operator (each object has its own individual LWeak reference count). More...
void	setUserData (UIntPtr data) const noexcept
	Store an unsigned integer value/pointer. More...
UIntPtr	userData () const noexcept
	Retrieves the stored unsigned integer value/pointer. More...

Session
void	setTTY (UInt32 tty) noexcept
	Switches session. More...
Int32	openDevice (const char *path, Int32 *fd) noexcept
	Open a device. More...
Int32	closeDevice (Int32 id) noexcept
	Closes a device. More...
libseat *	libseatHandle () const noexcept
	Libseat handle. More...
bool	enabled () const noexcept
	Check the session state. More...

Virtual Methods
virtual void	enabledChanged ()
	Notify a change in the enabled() property. More...
virtual void	outputPlugged (LOutput *output)
	New available output. More...
virtual void	outputUnplugged (LOutput *output)
	Disconnected output. More...
virtual void	inputDevicePlugged (LInputDevice *device)
	New available input device. More...
virtual void	inputDeviceUnplugged (LInputDevice *device)
	Disconnected input device. More...
virtual bool	isIdleStateInhibited () const
	Checks if the idle state is inhibited. More...
virtual void	onIdleListenerTimeout (const LIdleListener &listener)
	Notifies the timeout of an idle listener. More...
virtual void	onEvent (const LEvent &event)
	Notifies of any input event. More...
virtual void	nativeInputEvent (void *event)
	Native input backend events. More...
virtual bool	configureOutputsRequest (LClient *client, const std::vector< OutputConfiguration > &configurations)
	Handles a client request to configure outputs. More...

Additional Inherited Members
Public Types inherited from LFactoryObject
enum class	Type : Int32
	Base factory object types. More...
Protected Member Functions inherited from LObject
	LObject () noexcept=default
	Constructor of the LObject class. More...
virtual	~LObject () noexcept
	Destructor of the LObject class. More...
void	notifyDestruction () noexcept
	Notifies the object destruction. More...

Detailed Description

Group of input and output devices.

The LSeat class represents a collection of input and output devices such as a mouse, keyboard, touch screen, and displays (outputs). These devices are used within a session. Typically, for security reasons, access to these devices is restricted to a single process per session, often a Wayland compositor or X11 server.

To enable the libinput and DRM backends to manage devices without requiring superuser privileges, the openDevice() method is used to obtain device file descriptors. This method internally employs libseat.

By setting the environment variable LOUVRE_ENABLE_LIBSEAT to 0, libseat can be disabled, causing the compositor to launch without multi-session support. Consequently, certain features such as switching to another TTY may become unavailable.

Note

Disabling libseat may be necessary in scenarios where the compositor needs to be started remotely via SSH.

---

Class Documentation

Louvre::LSeat::OutputConfiguration

struct Louvre::LSeat::OutputConfiguration

Configuration parameters for an output.

This structure is used in configureOutputsRequest().

Class Members
LOutput &	output	The output to be configured.
bool	initialized	Whether to enable or disable the output, see LCompositor::addOutput() and LCompositor::removeOutput().
const LOutputMode &	mode	The desired output mode to be applied, see LOutput::setMode().
LPoint	pos	The desired output position to be applied, see LOutput::setPos().
LTransform	transform	The desired output transform to be applied, see LOutput::setTransform().
Float32	scale	The desired scale to be applied, see LOutput::setScale().

Constructor & Destructor Documentation

LSeat()

LSeat

(

const void *

params

)

Constructor of the LSeat class.

Parameters

params

Internal parameters provided in LCompositor::createObjectRequest().

~LSeat()

~LSeat

(

)

Destructor of the LSeat class.

Invoked after LCompositor::onAnticipatedObjectDestruction().

Member Function Documentation

gpus()

const std::vector< LGPU * > & gpus ( ) const

noexcept

Retrieves the available GPUs.

There is always at least one available GPU (even if virtual), and each output belongs to a single GPU.

outputs()

const std::vector< LOutput * > & outputs ( ) const

noexcept

Vector of available outputs.

This method provides a vector of currently available outputs. The vector includes connected outputs that can be initialized as well as those that are already initialized.
To obtain only initialized outputs, refer to LCompositor::outputs().

inputDevices()

const std::vector< LInputDevice * > & inputDevices ( ) const

noexcept

Vector of available input devices.

See also

inputDevicePlugged() and inputDeviceUnplugged().

idleInhibitorSurfaces()

const std::vector< LSurface * > & idleInhibitorSurfaces ( ) const

noexcept

Surfaces requesting to inhibit the idle state.

See also

LIdleListener for more details.

idleListeners()

const std::vector< const LIdleListener * > & idleListeners ( ) const

noexcept

Listeners used by clients to detect when the user has been idle for a specified amount of time.

See also

LIdleListener for more details.

setIsUserIdleHint()

void setIsUserIdleHint ( bool  isIdle )

noexcept

Sets a hint about the user's idle state.

Resetting all idle listener timers manually with LIdleListeners::resetTimer() each time an event occurs isn't very CPU-friendly, as multiple events can be triggered in a single main loop iteration.

Instead, by using this method (which only updates a boolean variable), we can ask Louvre to update all timers only once at the end of a main loop iteration.

Note

The value is automatically set to true at the start of each iteration.

See also

LIdleListener for more details.

isUserIdleHint()

bool isUserIdleHint ( ) const

noexcept

Hint about the user's idle state set with setIsUserIdleHint().

See also

LIdleListener for more details.

Returns

A boolean indicating the user's idle state. true if the user is idle, false otherwise.

name()

const char * name ( ) const

noexcept

The seat name.

This method returns the name of the seat (E.g. "seat0").

activeToplevel()

LToplevelRole * activeToplevel ( ) const

noexcept

Active toplevel surface.

This method returns the current LToplevelRole being configured with the LToplevelRole::State::Activated flag.
Only one toplevel surface can be active at a time, Louvre automatically deactivates other toplevels when one is activated.

Returns

The currently active LToplevelRole instance or nullptr if no toplevel is active.

toplevelResizeSessions()

const std::vector< LToplevelResizeSession * > & toplevelResizeSessions ( ) const

noexcept

Active LToplevelRole resize sessions.

See also

LToplevelResizeSession and LToplevelRole::startResizeRequest()

toplevelMoveSessions()

const std::vector< LToplevelMoveSession * > & toplevelMoveSessions ( ) const

noexcept

Active LToplevelRole move sessions.

See also

LToplevelMoveSession and LToplevelRole::startMoveRequest()

pointer()

LPointer* pointer ( ) const

inlinenoexcept

Access to pointer events.

Access to the LPointer instance used to receive pointer events from the backend and redirect them to clients.

keyboard()

LKeyboard* keyboard ( ) const

inlinenoexcept

Access to keyboard events.

Access to the LKeyboard instance used to receive keyboard events from the backend and redirect them to clients.

touch()

LTouch* touch ( ) const

inlinenoexcept

Access to touch events.

Access to the LTouch instance used to receive touch events from the backend and redirect them to clients.

dnd()

LDND* dnd ( ) const

inlinenoexcept

Access to the drag & drop session manager.

clipboard()

LClipboard* clipboard ( ) const

inlinenoexcept

Access to the clipboard manager.

dismissPopups()

void dismissPopups ( )

noexcept

Close all popups.

This method closes all active LPopupRole surfaces in reverse order of creation.

See also

LPopupRole::dismiss()

topmostPopup()

LPopupRole * topmostPopup ( ) const

noexcept

Retrieve the topmost popup role.

This method returns a pointer to the topmost popup.

Returns

A pointer to the topmost LPopupRole or nullptr if there is no popup.

setTTY()

void setTTY ( UInt32  tty )

noexcept

Switches session.

This method allows you to switch to another session (TTY). Louvre also allows switching sessions using the shortcuts Ctrl + Alt + [F1, F2, ..., F10].

Parameters

tty	TTY number.

openDevice()

Int32 openDevice ( const char *  path, Int32 *  fd  )

noexcept

Open a device.

Opens a device returning its ID and storing its file descriptor in fd.
The DRM and Libinput backends use this method to open GPUs and input devices respectively.

Parameters

path	Location of the device (E.g. "/dev/dri/card0")
fd	Stores the file descriptor.

Returns

The ID of the device or -1 in case of an error.

closeDevice()

Int32 closeDevice ( Int32  id )

noexcept

Closes a device.

This method is used by the input and graphic backends to close devices.

Parameters

id	The id of the device returned by openDevice().

Returns

0 if the device is closed successfully and -1 in case of error.

libseatHandle()

libseat * libseatHandle ( ) const

noexcept

Libseat handle.

struct libseat handle.

Note

Returns nullptr if libseat is not being used.

enabled()

bool enabled ( ) const

noexcept

Check the session state.

The session is considered disabled if the user is engaged in another active session (TTY).

Returns

true if the seat is active, false otherwise.

enabledChanged()

virtual void enabledChanged ( )

virtual

Notify a change in the enabled() property.

Override this virtual method if you want to be notified when the seat is enabled or disabled.
The seat is enabled when the user is in the session (TTY) in which the compositor is running, and disabled when switching to a different session.

See also

setTTY()

Default implementation

void LSeat::enabledChanged()
{
    if (!enabled())
        return;
 
    cursor()->setVisible(false);
    cursor()->setVisible(true);
    cursor()->move(1, 1);
    compositor()->repaintAllOutputs();
}

outputPlugged()

virtual void outputPlugged ( LOutput *  output )

virtual

New available output.

This event is invoked by the graphic backend when a new output is available, for example when connecting an external monitor through an HDMI port.
The default implementation initializes the new output and positions it at the end (right) of the already initialized outputs.

Default Implementation

void LSeat::outputPlugged(LOutput *output)
{
    // Probably a VR headset, meant to be leased by clients
    if (output->isNonDesktop())
    {
        output->setLeasable(true);
        return;
    }
 
    output->setScale(output->dpi() >= 200 ? 2 : 1);
 
    if (compositor()->outputs().empty())
        output->setPos(0);
    else
        output->setPos(compositor()->outputs().back()->pos() + LPoint(compositor()->outputs().back()->size().w(), 0));
 
    compositor()->addOutput(output);
    compositor()->repaintAllOutputs();
}

outputUnplugged()

virtual void outputUnplugged ( LOutput *  output )

virtual

Disconnected output.

This event is invoked by the graphic backend when an output is no longer available, for example when an external monitor connected to an HDMI port is disconnected.

The default implementation removes the output from the compositor and re-arranges the ones already initialized.

Note

Louvre automatically employs LCompositor::removeOutput() after this event, so calling it directly is not mandatory.

Default Implementation

void LSeat::outputUnplugged(LOutput *output)
{
    compositor()->removeOutput(output);
 
    Int32 totalWidth { 0 };
 
    for (LOutput *o : compositor()->outputs())
    {
        o->setPos(LPoint(totalWidth, 0));
        totalWidth += o->size().w();
    }
 
    compositor()->repaintAllOutputs();
}

inputDevicePlugged()

virtual void inputDevicePlugged ( LInputDevice *  device )

virtual

New available input device.

Default Implementation

void LSeat::inputDevicePlugged(LInputDevice *device)
{
    L_UNUSED(device);
}

inputDeviceUnplugged()

virtual void inputDeviceUnplugged ( LInputDevice *  device )

virtual

Disconnected input device.

Default Implementation

void LSeat::inputDeviceUnplugged(LInputDevice *device)
{
    L_UNUSED(device);
}

isIdleStateInhibited()

virtual bool isIdleStateInhibited ( ) const

virtual

Checks if the idle state is inhibited.

The default implementation returns true if at least one of the surfaces listed in idleInhibitorSurfaces() is mapped and visible on at least one output.

Note

Since the way of displaying surfaces is specific to each compositor, no additional checks are performed to determine if the surface is obscured by opaque areas. You may override this method to include such checks if needed.

See also

LIdleListener for more details.

Returns

Returns true if the idle state is inhibited, false otherwise.

Default Implementation

bool LSeat::isIdleStateInhibited() const
{
    for (LSurface *surface : idleInhibitorSurfaces())
        if (surface->mapped() && !surface->outputs().empty())
            return true;
 
    return false;
}

onIdleListenerTimeout()

virtual void onIdleListenerTimeout ( const LIdleListener &  listener )

virtual

Notifies the timeout of an idle listener.

If LIdleListener::resetTimer() is not called within this event, the LIdleListener::client() will be notified that the user is idle until LIdleListener::resetTimer() is called again.

If the idle state is being inhibited (see isIdleStateInhibited()) LIdleListener::resetTimer() should always be called.

See also

LIdleListener for more details.

Default Implementation

void LSeat::onIdleListenerTimeout(const LIdleListener &listener)
{
    if (isIdleStateInhibited())
        listener.resetTimer();
 
    /* If the timer is not reset, the client will assume the user is idle. */
}

onEvent()

virtual void onEvent ( const LEvent &  event )

virtual

Notifies of any input event.

This event is similar to nativeInputEvent(), but is only invoked for input event types currently supported by Louvre.

Default Implementation

void LSeat::onEvent(const LEvent &event)
{
    L_UNUSED(event)
 
    /*
     * for (const LIdleListener *idleListener : idleListeners())
     *     idleListener->resetTimer();
     *
     * Resetting all timers each time an event occurs is not CPU-friendly,
     * as multiple events can be triggered in a single main loop iteration.
     * Instead, using the option below (setIsUserIdleHint()) is more efficient.
     */
 
    /*
     * Setting this flag to false indicates the user wasn't idle during
     * this main loop iteration. If that's the case, Louvre will reset
     * all timers only once at the end of the iteration.
     * The flag is automatically set to true again afterwards.
     */
    setIsUserIdleHint(false);
}

nativeInputEvent()

virtual void nativeInputEvent ( void *  event )

virtual

Native input backend events.

Override this virtual method if you want to access all events generated by the input backend.

Parameters

event

Opaque handle to the native backend event. When using the Libinput backend it corresponds to a libinput_event struct

Note

Use LCompositor::inputBackendId() to determine which input backend is in use.

Default implementation

void LSeat::nativeInputEvent(void *event)
{
    L_UNUSED(event);
}

configureOutputsRequest()

virtual bool configureOutputsRequest ( LClient *  client, const std::vector< OutputConfiguration > &  configurations  )

virtual

Handles a client request to configure outputs.

Triggered by clients using the wlr-output-management protocol, such as wdisplays, wlr-randr, and wayland-displays.

The configurations vector contains all parameters the client intends to configure all available outputs with, including uninitialized ones (see outputs()).

The compositor can ignore the provided parameters and configure the outputs differently (e.g., to prevent overlapping). Returning true notifies the client that the configurations were fully or partially applied. Returning false indicates that the configurations failed to apply, and Louvre will revert all output parameters to their previous state.

Parameters

client	The client issuing the request.
configurations	Parameters to configure each available output.

Returns

true if the configurations were completely or partially applied, or false to revert changes.

Default implementation

bool LSeat::configureOutputsRequest(LClient *client, const std::vector<OutputConfiguration> &configurations)
{
    // All requests accepted by default (unsafe) see LCompositor::globalsFilter().
    L_UNUSED(client)
 
    for (const auto &conf : configurations)
    {
        conf.output.setPos(conf.pos);
        conf.output.setTransform(conf.transform);
        conf.output.setScale(conf.scale);
        conf.output.setMode(&conf.mode);
 
        if (conf.initialized)
            compositor()->addOutput(&conf.output);
        else
            compositor()->removeOutput(&conf.output);
    }
 
    // Revert changes if the configuration results in zero initialized outputs
    return !compositor()->outputs().empty();
}