LKeyboard Class Reference

Class for handling keyboard events. More...

Inheritance diagram for LKeyboard:

Public Member Functions
	LKeyboard (const void *params) noexcept
	Constructor of the LKeyboard class. More...
	~LKeyboard ()
	Destructor of the LKeyboard class. More...
void	setFocus (LSurface *surface)
	Set keyboard focus. More...
LSurface *	focus () const noexcept
	Focused surface. More...
void	setGrab (LSurface *surface)
	Sets a keyboard grab. More...
LSurface *	grab () const noexcept
	Gets the grab surface. More...
const LKeyboardModifiersEvent::Modifiers &	modifiers () const noexcept
	Current keyboard modifiers state. More...
Int32	keymapFd () const noexcept
	Keyboard map file descriptor. More...
Int32	keymapSize () const noexcept
	Size of the keyboard map in bytes. More...
UInt32	keymapFormat () const noexcept
	Keymap format. More...
Int32	repeatRate () const noexcept
	Repetition rate. More...
Int32	repeatDelay () const noexcept
	Repetition delay. More...
void	setRepeatInfo (Int32 rate, Int32 msDelay) noexcept
	Set the key repeat rate and delay. More...
xkb_keysym_t	keySymbol (UInt32 keyCode) noexcept
	Key symbol. More...
xkb_state *	keymapState () const noexcept
	Keymap state. More...
bool	isModActive (const char *name, xkb_state_component type) const noexcept
	Checks the state of a modifier. More...
const std::vector< UInt32 > &	pressedKeys () const noexcept
	All currently pressed key codes. More...
bool	isKeyCodePressed (UInt32 keyCode) const noexcept
	Checks if a key code is pressed. More...
bool	isKeySymbolPressed (xkb_keysym_t keySymbol) const noexcept
	Check if a key symbol is pressed. More...
bool	setKeymap (const char *rules=nullptr, const char *model=nullptr, const char *layout=nullptr, const char *variant=nullptr, const char *options=nullptr) noexcept
	Sets the keyboard map. More...
void	sendKeyEvent (const LKeyboardKeyEvent &event) noexcept
	Sends a key event to the currently focused surface. 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...

Virtual Methods
virtual void	keyEvent (const LKeyboardKeyEvent &event)
	Keyboard key event generated by the input backend. More...
virtual void	focusChanged ()
	Notifies that the focused surface has changed. 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

Class for handling keyboard events.

The LKeyboard class lets you handle keyboard events generated by the input backend, redirect them to clients, and configure parameters such as the keyboard map and key repeat rate.
There is a single instance of LKeyboard, which can be accessed from LSeat::keyboard().

Wayland Events

To send keyboard events to clients, you must first assign focus to a surface using setFocus() and then all subsequent keyboard events sent with sendKeyEvent() will be directed to that surface.

Constructor & Destructor Documentation

LKeyboard()

LKeyboard ( const void *  params )

noexcept

Constructor of the LKeyboard class.

There is a single instance of LKeyboard, which can be accessed from LSeat::keyboard().

Parameters

params

Internal parameters provided in LCompositor::createObjectRequest().

~LKeyboard()

~LKeyboard

(

)

Destructor of the LKeyboard class.

Invoked after LCompositor::onAnticipatedObjectDestruction().

Member Function Documentation

setFocus()

void setFocus

(

LSurface *

surface

)

Set keyboard focus.

This method assigns keyboard focus to the specified surface. Only one surface can have keyboard focus at a time, and this method automatically removes focus from any previously focused surface.
To remove focus from all surfaces, pass nullptr as the argument.

Note

Calling this method while there is a surface grabbing the keyboard is a no-op.

focus()

LSurface * focus ( ) const

noexcept

Focused surface.

See also

setFocus().

Returns

The focused surface or nullptr if no surface has keyboard focus.

setGrab()

void setGrab

(

LSurface *

surface

)

Sets a keyboard grab.

Setting a keyboard grab prevents other surfaces from gain focus with setFocus().
If the surface grabbing the keyboard is destroyed the grab is automatically assigned to its parent or unset if it has no parent.
For example, an LPopupRole can request to make a keyboard grab with LPopupRole::grabKeyboardRequest().

If 'surface' is set to nullptr, the keyboard grab is unset.

Parameters

surface

The surface that will grab the keyboard events or nullptr to disable it.

grab()

LSurface * grab ( ) const

noexcept

Gets the grab surface.

See also

setGrab()

Returns

The grabbing surface, or nullptr if unset.

modifiers()

const LKeyboardModifiersEvent::Modifiers & modifiers ( ) const

noexcept

Current keyboard modifiers state.

keymapFd()

Int32 keymapFd ( ) const

noexcept

Keyboard map file descriptor.

File descriptor of the XKB keyboard map assigned with setKeymap().

keymapSize()

Int32 keymapSize ( ) const

noexcept

Size of the keyboard map in bytes.

Size in bytes of the XKB keyboard map loaded with setKeymap().

keymapFormat()

UInt32 keymapFormat ( ) const

noexcept

Keymap format.

The keymap format can be either WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1, which indicates the presence of a valid XKB keymap set, or WL_KEYBOARD_KEYMAP_FORMAT_NO_KEYMAP, indicating an issue with the XKB system configuration.

repeatRate()

Int32 repeatRate ( ) const

noexcept

Repetition rate.

Number of repetitions per second of a key when held down, assigned with setRepeatInfo().

The default value is 32 repetitions per second.

repeatDelay()

Int32 repeatDelay ( ) const

noexcept

Repetition delay.

Delay in milliseconds before triggering the repetition of a key by holding it down, set with setRepeatInfo().

The default value is 500 ms.

setRepeatInfo()

void setRepeatInfo ( Int32  rate, Int32  msDelay  )

noexcept

Set the key repeat rate and delay.

Assigns the repeat rate and delay when holding down a key.

Note

This impacts how clients respond to a key being held down.

Parameters

rate	Number of repetitions per second. 0 turns off repetition.
msDelay	Delay in milliseconds before triggering the replay.

keySymbol()

xkb_keysym_t keySymbol ( UInt32  keyCode )

noexcept

Key symbol.

Returns the symbol of a raw key code generated by the input backend according to the current keymap state.

The complete list of symbols can be found in <xkbcommon/xkbcommon-keysyms.h>.

keymapState()

xkb_state * keymapState ( ) const

noexcept

Keymap state.

XKB keyboard map state.

isModActive()

bool isModActive ( const char *  name, xkb_state_component  type  ) const

noexcept

Checks the state of a modifier.

Parameters

name	Modifier name defined in <xkbcommon/xkbcommon_names.h> such as XKB_MOD_NAME_SHIFT, XKB_LED_NAME_CAPS, etc.
type	In XKB, the XKB_STATE_MODS_DEPRESSED, XKB_STATE_MODS_LATCHED, XKB_STATE_MODS_LOCKED, and XKB_STATE_MODS_EFFECTIVE are flags used to represent different aspects of the keyboard modifier keys' states.

XKB_STATE_MODS_DEPRESSED: This flag represents the currently depressed (pressed down) modifiers. When a modifier key is pressed, it falls into the depressed state. This flag helps identify which modifiers are currently held down.

XKB_STATE_MODS_LATCHED: This flag represents modifiers that are latched. A latched modifier is one that will be activated with the next non-modifier key press. Once the latched modifier is used, it returns to its original state.

XKB_STATE_MODS_LOCKED: This flag represents modifiers that are locked. When a modifier is locked, it stays active until explicitly unlocked. For example, if Caps Lock is activated, the Caps Lock state is locked until Caps Lock is pressed again.

XKB_STATE_MODS_EFFECTIVE: This flag represents the effective state of the modifiers. It takes into account the depressed, latched, and locked states to provide a combined view of the current modifier key states.

Returns

true if the modifier is active and false otherwise.

pressedKeys()

const std::vector< UInt32 > & pressedKeys ( ) const

noexcept

All currently pressed key codes.

isKeyCodePressed()

bool isKeyCodePressed ( UInt32  keyCode ) const

noexcept

Checks if a key code is pressed.

isKeySymbolPressed()

bool isKeySymbolPressed ( xkb_keysym_t  keySymbol ) const

noexcept

Check if a key symbol is pressed.

setKeymap()

bool setKeymap ( const char *  rules = nullptr, const char *  model = nullptr, const char *  layout = nullptr, const char *  variant = nullptr, const char *  options = nullptr  )

noexcept

Sets the keyboard map.

This method finds and assigns a keyboard map that matches the parameters passed in the arguments.
The keyboard map is automatically sent to clients when they connect to the compositor and use the wl_keyboard interface of the Wayland protocol. If a client is already connected, Louvre re-sends it the new keyboard map.

Parameters

rules	Rules on how to interpret the other arguments. Can be nullptr. More information.
model	Keyboard model. Can be nullptr. More information.
layout	Keyboard layouts separated by comma (e.g. "latam"). Can be nullptr. More information.
variant	Variants of layouts. Can be nullptr. More information.
options	Preferences not related to layouts. Can be nullptr. More information.

sendKeyEvent()

void sendKeyEvent ( const LKeyboardKeyEvent &  event )

noexcept

Sends a key event to the currently focused surface.

See also

setFocus() and setGrab().

keyEvent()

virtual void keyEvent ( const LKeyboardKeyEvent &  event )

virtual

Keyboard key event generated by the input backend.

Default implementation

void LKeyboard::keyEvent(const LKeyboardKeyEvent &event)
{
    const bool sessionLocked { sessionLockManager()->state() != LSessionLockManager::Unlocked };
 
    sendKeyEvent(event);
 
    const bool L_CTRL      { isKeyCodePressed(KEY_LEFTCTRL) };
    const bool L_SHIFT     { isKeyCodePressed(KEY_LEFTSHIFT) };
    const bool mods        { isKeyCodePressed(KEY_LEFTALT) && L_CTRL };
    const xkb_keysym_t sym { keySymbol(event.keyCode()) };
 
    if (event.state() == LKeyboardKeyEvent::Released)
    {
        if (event.keyCode() == KEY_ESC && L_CTRL && L_SHIFT)
        {
            compositor()->finish();
            return;
        }
        else if (L_CTRL && !L_SHIFT)
            seat()->dnd()->setPreferredAction(LDND::Copy);
        else if (!L_CTRL && L_SHIFT)
            seat()->dnd()->setPreferredAction(LDND::Move);
        else if (!L_CTRL && !L_SHIFT)
            seat()->dnd()->setPreferredAction(LDND::NoAction);
 
        if (sessionLocked)
            return;
 
        if (event.keyCode() == KEY_F1 && !mods)
            LLauncher::launch("weston-terminal");
        else if (L_CTRL && (sym == XKB_KEY_q || sym == XKB_KEY_Q))
        {
            if (focus())
                focus()->client()->destroyLater();
        }
        else if (L_CTRL && (sym == XKB_KEY_m || sym == XKB_KEY_M))
        {
            if (focus() && focus()->toplevel() && !focus()->toplevel()->fullscreen())
                focus()->setMinimized(true);
        }
        // Screenshot
        else if (L_CTRL && L_SHIFT && event.keyCode() == KEY_3)
        {
            if (cursor()->output() && cursor()->output()->bufferTexture(0))
            {
                std::filesystem::path path { getenvString("HOME") };
 
                if (path.empty())
                    return;
 
                path /= "Desktop/Louvre_Screenshoot_";
 
                char timeString[32];
                const auto now { std::chrono::system_clock::now() };
                const auto time { std::chrono::system_clock::to_time_t(now) };
                std::strftime(timeString, sizeof(timeString), "%Y-%m-%d %H:%M:%S.png", std::localtime(&time));
 
                path += timeString;
 
                cursor()->output()->bufferTexture(0)->save(path);
            }
        }
    }
 
    // Key pressed
    else
    {
        // CTRL sets Copy as the preferred action in drag & drop session
        if (L_CTRL)
            seat()->dnd()->setPreferredAction(LDND::Copy);
 
        // SHIFT sets Move as the preferred action in drag & drop session
        else if (L_SHIFT)
            seat()->dnd()->setPreferredAction(LDND::Move);
    }
}

focusChanged()

virtual void focusChanged ( )

virtual

Notifies that the focused surface has changed.

Default Implementation

void LKeyboard::focusChanged()
{
    /* No default implementation. */
}