libxkbcommon: Keyboard State

libxkbcommon 1.13.2 Library implementing the XKB specification for parsing keyboard descriptions and handling keyboard state

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Enumerations | Functions
Keyboard State

## Enumerations
enum | xkb_key_direction { XKB_KEY_UP , XKB_KEY_DOWN }
enum | xkb_state_component { XKB_STATE_MODS_DEPRESSED = (1 << 0) , XKB_STATE_MODS_LATCHED = (1 << 1) , XKB_STATE_MODS_LOCKED = (1 << 2) , XKB_STATE_MODS_EFFECTIVE = (1 << 3) , XKB_STATE_LAYOUT_DEPRESSED = (1 << 4) , XKB_STATE_LAYOUT_LATCHED = (1 << 5) , XKB_STATE_LAYOUT_LOCKED = (1 << 6) , XKB_STATE_LAYOUT_EFFECTIVE = (1 << 7) , XKB_STATE_LEDS = (1 << 8) }
enum | xkb_state_match { XKB_STATE_MATCH_ANY = (1 << 0) , XKB_STATE_MATCH_ALL = (1 << 1) , XKB_STATE_MATCH_NON_EXCLUSIVE = (1 << 16) }
enum | xkb_consumed_mode { XKB_CONSUMED_MODE_XKB , XKB_CONSUMED_MODE_GTK }

## Functions
XKB_EXPORT struct xkb_state * | xkb_state::xkb_state_new (struct xkb_keymap *keymap)
XKB_EXPORT struct xkb_state * | xkb_state::xkb_state_ref (struct xkb_state *state)
XKB_EXPORT void | xkb_state::xkb_state_unref (struct xkb_state *state)
XKB_EXPORT struct xkb_keymap * | xkb_state::xkb_state_get_keymap (struct xkb_state *state)
XKB_EXPORT enum xkb_state_component | xkb_state::xkb_state_update_key (struct xkb_state *state, xkb_keycode_t key, enum xkb_key_direction direction)
XKB_EXPORT enum xkb_state_component | xkb_state::xkb_state_update_latched_locked (struct xkb_state *state, xkb_mod_mask_t affect_latched_mods, xkb_mod_mask_t latched_mods, bool affect_latched_layout, int32_t latched_layout, xkb_mod_mask_t affect_locked_mods, xkb_mod_mask_t locked_mods, bool affect_locked_layout, int32_t locked_layout)
XKB_EXPORT enum xkb_state_component | xkb_state::xkb_state_update_mask (struct xkb_state *state, xkb_mod_mask_t depressed_mods, xkb_mod_mask_t latched_mods, xkb_mod_mask_t locked_mods, xkb_layout_index_t depressed_layout, xkb_layout_index_t latched_layout, xkb_layout_index_t locked_layout)
XKB_EXPORT int | xkb_state::xkb_state_key_get_syms (struct xkb_state *state, xkb_keycode_t key, const xkb_keysym_t **syms_out)
XKB_EXPORT int | xkb_state::xkb_state_key_get_utf8 (struct xkb_state *state, xkb_keycode_t key, char *buffer, size_t size)
XKB_EXPORT uint32_t | xkb_state::xkb_state_key_get_utf32 (struct xkb_state *state, xkb_keycode_t key)
XKB_EXPORT xkb_keysym_t | xkb_state::xkb_state_key_get_one_sym (struct xkb_state *state, xkb_keycode_t key)
XKB_EXPORT xkb_layout_index_t | xkb_state::xkb_state_key_get_layout (struct xkb_state *state, xkb_keycode_t key)
XKB_EXPORT xkb_level_index_t | xkb_state::xkb_state_key_get_level (struct xkb_state *state, xkb_keycode_t key, xkb_layout_index_t layout)
XKB_EXPORT xkb_mod_mask_t | xkb_state::xkb_state_serialize_mods (struct xkb_state *state, enum xkb_state_component components)
XKB_EXPORT xkb_layout_index_t | xkb_state::xkb_state_serialize_layout (struct xkb_state *state, enum xkb_state_component components)
XKB_EXPORT int | xkb_state::xkb_state_mod_name_is_active (struct xkb_state *state, const char *name, enum xkb_state_component type)
XKB_EXPORT int | xkb_state::xkb_state_mod_names_are_active (struct xkb_state *state, enum xkb_state_component type, enum xkb_state_match match,...)
XKB_EXPORT int | xkb_state::xkb_state_mod_index_is_active (struct xkb_state *state, xkb_mod_index_t idx, enum xkb_state_component type)
XKB_EXPORT int | xkb_state::xkb_state_mod_indices_are_active (struct xkb_state *state, enum xkb_state_component type, enum xkb_state_match match,...)
XKB_EXPORT xkb_mod_mask_t | xkb_state::xkb_state_key_get_consumed_mods2 (struct xkb_state *state, xkb_keycode_t key, enum xkb_consumed_mode mode)
XKB_EXPORT xkb_mod_mask_t | xkb_state::xkb_state_key_get_consumed_mods (struct xkb_state *state, xkb_keycode_t key)
XKB_EXPORT int | xkb_state::xkb_state_mod_index_is_consumed2 (struct xkb_state *state, xkb_keycode_t key, xkb_mod_index_t idx, enum xkb_consumed_mode mode)
XKB_EXPORT int | xkb_state::xkb_state_mod_index_is_consumed (struct xkb_state *state, xkb_keycode_t key, xkb_mod_index_t idx)
XKB_EXPORT xkb_mod_mask_t | xkb_state::xkb_state_mod_mask_remove_consumed (struct xkb_state *state, xkb_keycode_t key, xkb_mod_mask_t mask)
XKB_EXPORT int | xkb_state::xkb_state_layout_name_is_active (struct xkb_state *state, const char *name, enum xkb_state_component type)
XKB_EXPORT int | xkb_state::xkb_state_layout_index_is_active (struct xkb_state *state, xkb_layout_index_t idx, enum xkb_state_component type)
XKB_EXPORT int | xkb_state::xkb_state_led_name_is_active (struct xkb_state *state, const char *name)
XKB_EXPORT int | xkb_state::xkb_state_led_index_is_active (struct xkb_state *state, xkb_led_index_t idx)

## Detailed Description

Creating, destroying and manipulating keyboard state objects.

### Server State and Client State

The xkb_state API is used by two distinct actors in most window-system architectures:

1. A server - for example, a Wayland compositor, an X11 server, an evdev listener.

   Servers maintain the XKB state for a device according to input events from the device, such as key presses and releases, and out-of-band events from the user, like UI layout switchers.

2. A client - for example, a Wayland client, an X11 client.

   Clients do not listen to input from the device; instead, whenever the server state changes, the server serializes the state and notifies the clients that the state has changed; the clients then update the state from the serialization.

Some entry points in the xkb_state API are only meant for servers and some are only meant for clients, and the two should generally not be mixed.

### Consumed Modifiers

Some functions, like xkb_state::xkb_state_key_get_syms(), look at the state of the modifiers in the keymap and derive from it the correct shift level to use for the key. For example, in a US layout, pressing the key labeled <A> while the Shift modifier is active, generates the keysym A. In this case, the Shift modifier is said to be consumed. However, the Num Lock modifier does not affect this translation at all, even if it is active, so it is not consumed by this translation.

It may be desirable for some application to not reuse consumed modifiers for further processing, e.g. for hotkeys or keyboard shortcuts. To understand why, consider some requirements from a standard shortcut mechanism, and how they are implemented:

1. The shortcut’s modifiers must match exactly to the state. For example, it is possible to bind separate actions to <Alt><Tab> and to <Alt><Shift><Tab>. Further, if only <Alt><Tab> is bound to an action, pressing <Alt><Shift><Tab> should not trigger the shortcut. Effectively, this means that the modifiers are compared using the equality operator (==).
2. Only relevant modifiers are considered for the matching. For example, Caps Lock and Num Lock should not generally affect the matching, e.g. when matching <Alt><Tab> against the state, it does not matter whether Num Lock is active or not. These relevant, or significant, modifiers usually include Alt, Control, Shift, Super and similar. Effectively, this means that non-significant modifiers are masked out, before doing the comparison as described above.
3. The matching must be independent of the layout/keymap. For example, the <Plus> (+) symbol is found on the first level on some layouts, but requires holding Shift on others. If you simply bind the action to the <Plus> keysym, it would work for the unshifted kind, but not for the others, because the match against Shift would fail. If you bind the action to <Shift><Plus>, only the shifted kind would work. So what is needed is to recognize that Shift is used up in the translation of the keysym itself, and therefore should not be included in the matching. Effectively, this means that consumed modifiers (Shift in this example) are masked out as well, before doing the comparison.

In summary, this is approximately how the matching would be performed:

(keysym == shortcut_keysym) &&
((state_mods & ~consumed_mods & significant_mods) == shortcut_mods)

`state_mods` are the modifiers reported by xkb_state::xkb_state_mod_index_is_active() and similar functions. `consumed_mods` are the modifiers reported by xkb_state::xkb_state_mod_index_is_consumed() and similar functions. `significant_mods` are decided upon by the application/toolkit/user; it is up to them to decide whether these are configurable or hard-coded.

## Enumeration Type Documentation

## ◆ xkb_key_direction

enum xkb_key_direction

Specifies the direction of the key (press / release).

Enumerator
XKB_KEY_UP | The key was released.
XKB_KEY_DOWN | The key was pressed.

## ◆ xkb_state_component

enum xkb_state_component

Modifier and layout types for state objects.

This enum is bitmaskable, e.g. (XKB_STATE_MODS_DEPRESSED | XKB_STATE_MODS_LATCHED) is valid to exclude locked modifiers.

In XKB, the DEPRESSED components are also known as base.

Enumerator
XKB_STATE_MODS_DEPRESSED | Depressed modifiers, i.e. a key is physically holding them.
XKB_STATE_MODS_LATCHED | Latched modifiers, i.e. will be unset after the next non-modifier key press.
XKB_STATE_MODS_LOCKED | Locked modifiers, i.e. will be unset after the key provoking the lock has been pressed again.
XKB_STATE_MODS_EFFECTIVE | Effective modifiers, i.e. currently active and affect key processing (derived from the other state components). Use this unless you explicitly care how the state came about.
XKB_STATE_LAYOUT_DEPRESSED | Depressed layout, i.e. a key is physically holding it.
XKB_STATE_LAYOUT_LATCHED | Latched layout, i.e. will be unset after the next non-modifier key press.
XKB_STATE_LAYOUT_LOCKED | Locked layout, i.e. will be unset after the key provoking the lock has been pressed again.
XKB_STATE_LAYOUT_EFFECTIVE | Effective layout, i.e. currently active and affects key processing (derived from the other state components). Use this unless you explicitly care how the state came about.
XKB_STATE_LEDS | LEDs (derived from the other state components).

## ◆ xkb_state_match

enum xkb_state_match

Match flags for xkb_state::xkb_state_mod_indices_are_active() and xkb_state::xkb_state_mod_names_are_active(), specifying the conditions for a successful match.

XKB_STATE_MATCH_NON_EXCLUSIVE is bitmaskable with the other modes.

Enumerator
XKB_STATE_MATCH_ANY | Returns true if any of the modifiers are active.
XKB_STATE_MATCH_ALL | Returns true if all of the modifiers are active.
XKB_STATE_MATCH_NON_EXCLUSIVE | Makes matching non-exclusive, i.e. will not return false if a modifier not specified in the arguments is active.

## ◆ xkb_consumed_mode

enum xkb_consumed_mode

Consumed modifiers mode.

There are several possible methods for deciding which modifiers are consumed and which are not, each applicable for different systems or situations. The mode selects the method to use.

Keep in mind that in all methods, the keymap may decide to preserve a modifier, meaning it is not reported as consumed even if it would have otherwise.

Enumerator
XKB_CONSUMED_MODE_XKB | This is the mode defined in the XKB specification and used by libX11. A modifier is consumed if and only if it may affect key translation. For example, if Control+Alt+<Backspace> produces some assigned keysym, then when pressing just <Backspace>, Control and Alt are consumed, even though they are not active, since if they were active they would have affected key translation.
XKB_CONSUMED_MODE_GTK | This is the mode used by the GTK+ toolkit. The mode consists of the following two independent heuristics: The currently active set of modifiers, excluding modifiers which do not affect the key (as described for XKB_CONSUMED_MODE_XKB), are considered consumed, if the keysyms produced when all of them are active are different from the keysyms produced when no modifiers are active. A single modifier is considered consumed if the keysyms produced for the key when it is the only active modifier are different from the keysyms produced when no modifiers are active.

## Function Documentation

## ◆ xkb_state_new()

XKB_EXPORT struct xkb_state * xkb_state_new | ( | struct xkb_keymap * | keymap | ) |

Create a new keyboard state object.

Parameters

  keymap | The keymap which the state will use.

Returns
  A new keyboard state object, or NULL on failure.

## ◆ xkb_state_ref()

XKB_EXPORT struct xkb_state * xkb_state_ref | ( | struct xkb_state * | state | ) |

Take a new reference on a keyboard state object.

Returns
  The passed in object.

## ◆ xkb_state_unref()

XKB_EXPORT void xkb_state_unref | ( | struct xkb_state * | state | ) |

Release a reference on a keyboard state object, and possibly free it.

Parameters

  state | The state. If it is NULL, this function does nothing.

## ◆ xkb_state_get_keymap()

XKB_EXPORT struct xkb_keymap * xkb_state_get_keymap | ( | struct xkb_state * | state | ) |

Get the keymap which a keyboard state object is using.

Returns
  The keymap which was passed to xkb_state_new() when creating this state object.

This function does not take a new reference on the keymap; you must explicitly reference it yourself if you plan to use it beyond the lifetime of the state.

## ◆ xkb_state_update_key()

XKB_EXPORT enum xkb_state_component xkb_state_update_key | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | enum xkb_key_direction | direction )

Update the keyboard state to reflect a given key being pressed or released.

This entry point is intended for server applications and should not be used by client applications; see Server State and Client State for details.

A series of calls to this function should be consistent; that is, a call with XKB_KEY_DOWN for a key should be matched by an XKB_KEY_UP; if a key is pressed twice, it should be released twice; etc. Otherwise (e.g. due to missed input events), situations like “stuck modifiers” may occur.

This function is often used in conjunction with the function xkb_state_key_get_syms() (or xkb_state_key_get_one_sym()), for example, when handling a key event. In this case, you should prefer to get the keysyms before updating the key, such that the keysyms reported for the key event are not affected by the event itself. This is the conventional behavior.

Returns
  A mask of state components that have changed as a result of the update. If nothing in the state has changed, returns 0.

See also
  xkb_state_update_mask()

## ◆ xkb_state_update_latched_locked()

XKB_EXPORT enum xkb_state_component xkb_state_update_latched_locked | ( | struct xkb_state * | state,
|  | xkb_mod_mask_t | affect_latched_mods,
|  | xkb_mod_mask_t | latched_mods,
|  | bool | affect_latched_layout,
|  | int32_t | latched_layout,
|  | xkb_mod_mask_t | affect_locked_mods,
|  | xkb_mod_mask_t | locked_mods,
|  | bool | affect_locked_layout,
|  | int32_t | locked_layout )

Update the keyboard state to change the latched and locked state of the modifiers and layout.

This entry point is intended for server applications and should not be used by client applications; see Server State and Client State for details.

Use this function to update the latched and locked state according to “out of band” (non-device) inputs, such as UI layout switchers.

Layout out of range

  If the effective layout, after taking into account the depressed, latched and locked layout, is out of range (negative or greater than the maximum layout), it is brought into range. Currently, the layout is wrapped using integer modulus (with negative values wrapping from the end). The wrapping behavior may be made configurable in the future.

Parameters

  state | The keyboard state object.
  affect_latched_mods |
  latched_mods | Modifiers to set as latched or unlatched. Only modifiers in `affect_latched_mods` are considered.
  affect_latched_layout |
  latched_layout | Layout to latch. Only considered if `affect_latched_layout` is true. Maybe be out of range (including negative) – see note above.
  affect_locked_mods |
  locked_mods | Modifiers to set as locked or unlocked. Only modifiers in `affect_locked_mods` are considered.
  affect_locked_layout |
  locked_layout | Layout to lock. Only considered if `affect_locked_layout` is true. Maybe be out of range (including negative) – see note above.

Returns
  A mask of state components that have changed as a result of the update. If nothing in the state has changed, returns 0.

See also
  xkb_state_update_mask()

## ◆ xkb_state_update_mask()

XKB_EXPORT enum xkb_state_component xkb_state_update_mask | ( | struct xkb_state * | state,
|  | xkb_mod_mask_t | depressed_mods,
|  | xkb_mod_mask_t | latched_mods,
|  | xkb_mod_mask_t | locked_mods,
|  | xkb_layout_index_t | depressed_layout,
|  | xkb_layout_index_t | latched_layout,
|  | xkb_layout_index_t | locked_layout )

Update a keyboard state from a set of explicit masks.

This entry point is intended for client applications; see Server State and Client State for details. Server applications should use xkb_state_update_key() instead.

All parameters must always be passed, or the resulting state may be incoherent.

Warning
  The serialization is lossy and will not survive round trips; it must only be used to feed client state objects, and must not be used to update the server state.

Returns
  A mask of state components that have changed as a result of the update. If nothing in the state has changed, returns 0.

See also
  xkb_state_component
  xkb_state_update_key()

## ◆ xkb_state_key_get_syms()

XKB_EXPORT int xkb_state_key_get_syms | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | const xkb_keysym_t ** | syms_out )

Get the keysyms obtained from pressing a particular key in a given keyboard state.

Get the keysyms for a key according to the current active layout, modifiers and shift level for the key, as determined by a keyboard state.

Parameters

  [in] | state | The keyboard state object.
  [in] | key | The keycode of the key.
  [out] | syms_out | An immutable array of keysyms corresponding the key in the given keyboard state.

As an extension to XKB, this function can return more than one keysym. If you do not want to handle this case, you can use xkb_state_key_get_one_sym() for a simpler interface.

Returns
  The number of keysyms in the syms_out array. If no keysyms are produced by the key in the given keyboard state, returns 0 and sets syms_out to NULL.

This function performs Capitalization Keysym Transformations.

Since
  1.9.0 This function now performs Keysym Transformations.

## ◆ xkb_state_key_get_utf8()

XKB_EXPORT int xkb_state_key_get_utf8 | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | char * | buffer,
|  | size_t | size )

Get the Unicode/UTF-8 string obtained from pressing a particular key in a given keyboard state.

Parameters

  [in] | state | The keyboard state object.
  [in] | key | The keycode of the key.
  [out] | buffer | A buffer to write the string into.
  [in] | size | Size of the buffer.

Warning
  If the buffer passed is too small, the string is truncated (though still NULL-terminated).

Returns
  The number of bytes required for the string, excluding the NULL byte. If there is nothing to write, returns 0.

You may check if truncation has occurred by comparing the return value with the size of `buffer`, similarly to the snprintf(3) function. You may safely pass NULL and 0 to `buffer` and `size` to find the required size (without the NULL-byte).

This function performs Capitalization and Control Keysym Transformations.

Since
  0.4.1

## ◆ xkb_state_key_get_utf32()

XKB_EXPORT uint32_t xkb_state_key_get_utf32 | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key )

Get the Unicode/UTF-32 codepoint obtained from pressing a particular key in a a given keyboard state.

Returns
  The UTF-32 representation for the key, if it consists of only a single codepoint. Otherwise, returns 0.

This function performs Capitalization and Control Keysym Transformations.

Since
  0.4.1

## ◆ xkb_state_key_get_one_sym()

XKB_EXPORT xkb_keysym_t xkb_state_key_get_one_sym | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key )

Get the single keysym obtained from pressing a particular key in a given keyboard state.

This function is similar to xkb_state_key_get_syms(), but intended for users which cannot or do not want to handle the case where multiple keysyms are returned (in which case this function is preferred).

Returns
  The keysym. If the key does not have exactly one keysym, returns XKB_KEY_NoSymbol.

This function performs Capitalization Keysym Transformations.

See also
  xkb_state_key_get_syms()

## ◆ xkb_state_key_get_layout()

XKB_EXPORT xkb_layout_index_t xkb_state_key_get_layout | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key )

Get the effective layout index for a key in a given keyboard state.

Returns
  The layout index for the key in the given keyboard state. If the given keycode is invalid, or if the key is not included in any layout at all, returns XKB_LAYOUT_INVALID.

Invariant
  If the returned layout is valid, the following always holds:
  xkb_state_key_get_layout(state, key) < xkb_keymap_num_layouts_for_key(keymap, key)
  xkb_state::xkb_state_key_get_layout
  XKB_EXPORT xkb_layout_index_t xkb_state_key_get_layout(struct xkb_state *state, xkb_keycode_t key)
  Get the effective layout index for a key in a given keyboard state.

## ◆ xkb_state_key_get_level()

XKB_EXPORT xkb_level_index_t xkb_state_key_get_level | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | xkb_layout_index_t | layout )

Get the effective shift level for a key in a given keyboard state and layout.

Parameters

  state | The keyboard state.
  key | The keycode of the key.
  layout | The layout for which to get the shift level. This must be smaller than: xkb_keymap_num_layouts_for_key(keymap, key) usually it would be: xkb_state_key_get_layout(state, key)

Returns
  The shift level index. If the key or layout are invalid, returns XKB_LEVEL_INVALID.

Invariant
  If the returned level is valid, the following always holds:
  xkb_state_key_get_level(state, key, layout) < xkb_keymap_num_levels_for_key(keymap, key, layout)
  xkb_state::xkb_state_key_get_level
  XKB_EXPORT xkb_level_index_t xkb_state_key_get_level(struct xkb_state *state, xkb_keycode_t key, xkb_layout_index_t layout)
  Get the effective shift level for a key in a given keyboard state and layout.

## ◆ xkb_state_serialize_mods()

XKB_EXPORT xkb_mod_mask_t xkb_state_serialize_mods | ( | struct xkb_state * | state,
|  | enum xkb_state_component | components )

The counterpart to xkb_state::xkb_state_update_mask() for modifiers, to be used on the server side of serialization.

This entry point is intended for server applications; see Server State and Client State for details. Client applications should use the xkb_state_mod_*_is_active API.

Parameters

  state | The keyboard state.
  components | A mask of the modifier state components to serialize. State components other than XKB_STATE_MODS_* are ignored. If XKB_STATE_MODS_EFFECTIVE is included, all other state components are ignored.

Returns
  A xkb_mod_mask_t representing the given components of the modifier state.

## ◆ xkb_state_serialize_layout()

XKB_EXPORT xkb_layout_index_t xkb_state_serialize_layout | ( | struct xkb_state * | state,
|  | enum xkb_state_component | components )

The counterpart to xkb_state::xkb_state_update_mask() for layouts, to be used on the server side of serialization.

This entry point is intended for server applications; see Server State and Client State for details. Client applications should use the xkb_state_layout_*_is_active API.

Parameters

  state | The keyboard state.
  components | A mask of the layout state components to serialize. State components other than XKB_STATE_LAYOUT_* are ignored. If XKB_STATE_LAYOUT_EFFECTIVE is included, all other state components are ignored.

Returns
  A layout index representing the given components of the layout state.

## ◆ xkb_state_mod_name_is_active()

XKB_EXPORT int xkb_state_mod_name_is_active | ( | struct xkb_state * | state,
|  | const char * | name,
|  | enum xkb_state_component | type )

Test whether a modifier is active in a given keyboard state by name.

Warning
  For virtual modifiers, this function may overmatch in case there are virtual modifiers with overlapping mappings to real modifiers.

Returns
  1 if the modifier is active, 0 if it is not. If the modifier name does not exist in the keymap, returns -1.

Since
  0.1.0: Works only with real modifiers
  1.8.0: Works also with virtual modifiers

## ◆ xkb_state_mod_names_are_active()

XKB_EXPORT int xkb_state_mod_names_are_active | ( | struct xkb_state * | state,
|  | enum xkb_state_component | type,
|  | enum xkb_state_match | match,
|  |  | ... )

Test whether a set of modifiers are active in a given keyboard state by name.

Warning
  For virtual modifiers, this function may overmatch in case there are virtual modifiers with overlapping mappings to real modifiers.

Parameters

  state | The keyboard state.
  type | The component of the state against which to match the given modifiers.
  match | The manner by which to match the state against the given modifiers.
  ... | The set of of modifier names to test, terminated by a NULL argument (sentinel).

Returns
  1 if the modifiers are active, 0 if they are not. If any of the modifier names do not exist in the keymap, returns -1.

Since
  0.1.0: Works only with real modifiers
  1.8.0: Works also with virtual modifiers

## ◆ xkb_state_mod_index_is_active()

XKB_EXPORT int xkb_state_mod_index_is_active | ( | struct xkb_state * | state,
|  | xkb_mod_index_t | idx,
|  | enum xkb_state_component | type )

Test whether a modifier is active in a given keyboard state by index.

Warning
  For virtual modifiers, this function may overmatch in case there are virtual modifiers with overlapping mappings to real modifiers.

Returns
  1 if the modifier is active, 0 if it is not. If the modifier index is invalid in the keymap, returns -1.

Since
  0.1.0: Works only with real modifiers
  1.8.0: Works also with virtual modifiers

## ◆ xkb_state_mod_indices_are_active()

XKB_EXPORT int xkb_state_mod_indices_are_active | ( | struct xkb_state * | state,
|  | enum xkb_state_component | type,
|  | enum xkb_state_match | match,
|  |  | ... )

Test whether a set of modifiers are active in a given keyboard state by index.

Warning
  For virtual modifiers, this function may overmatch in case there are virtual modifiers with overlapping mappings to real modifiers.

Parameters

  state | The keyboard state.
  type | The component of the state against which to match the given modifiers.
  match | The manner by which to match the state against the given modifiers.
  ... | The set of of modifier indices to test, terminated by a XKB_MOD_INVALID argument (sentinel).

Returns
  1 if the modifiers are active, 0 if they are not. If any of the modifier indices are invalid in the keymap, returns -1.

Since
  0.1.0: Works only with real modifiers
  1.8.0: Works also with virtual modifiers

## ◆ xkb_state_key_get_consumed_mods2()

XKB_EXPORT xkb_mod_mask_t xkb_state_key_get_consumed_mods2 | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | enum xkb_consumed_mode | mode )

Get the mask of modifiers consumed by translating a given key.

Parameters

  state | The keyboard state.
  key | The keycode of the key.
  mode | The consumed modifiers mode to use; see enum description.

Returns
  a mask of the consumed real modifiers modifiers.

Since
  0.7.0

## ◆ xkb_state_key_get_consumed_mods()

XKB_EXPORT xkb_mod_mask_t xkb_state_key_get_consumed_mods | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key )

Same as xkb_state_key_get_consumed_mods2() with mode XKB_CONSUMED_MODE_XKB.

Since
  0.4.1

## ◆ xkb_state_mod_index_is_consumed2()

XKB_EXPORT int xkb_state_mod_index_is_consumed2 | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | xkb_mod_index_t | idx,
|  | enum xkb_consumed_mode | mode )

Test whether a modifier is consumed by keyboard state translation for a key.

Warning
  For virtual modifiers, this function may overmatch in case there are virtual modifiers with overlapping mappings to real modifiers.

Parameters

  state | The keyboard state.
  key | The keycode of the key.
  idx | The index of the modifier to check.
  mode | The consumed modifiers mode to use; see enum description.

Returns
  1 if the modifier is consumed, 0 if it is not. If the modifier index is not valid in the keymap, returns -1.

See also
  xkb_state_mod_mask_remove_consumed()
  xkb_state_key_get_consumed_mods()

Since
  0.7.0: Works only with real modifiers
  1.8.0: Works also with virtual modifiers

## ◆ xkb_state_mod_index_is_consumed()

XKB_EXPORT int xkb_state_mod_index_is_consumed | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | xkb_mod_index_t | idx )

Same as xkb_state_mod_index_is_consumed2() with mode ::XKB_CONSUMED_MOD_XKB.

Warning
  For virtual modifiers, this function may overmatch in case there are virtual modifiers with overlapping mappings to real modifiers.

Since
  0.4.1: Works only with real modifiers
  1.8.0: Works also with virtual modifiers

## ◆ xkb_state_mod_mask_remove_consumed()

XKB_EXPORT xkb_mod_mask_t xkb_state_mod_mask_remove_consumed | ( | struct xkb_state * | state,
|  | xkb_keycode_t | key,
|  | xkb_mod_mask_t | mask )

Remove consumed modifiers from a modifier mask for a key.

Deprecated
  Use xkb_state_key_get_consumed_mods2() instead.

Takes the given modifier mask, and removes all modifiers which are consumed for that particular key (as in xkb_state_mod_index_is_consumed()).

Returns
  a mask of real modifiers modifiers.

See also
  xkb_state_mod_index_is_consumed()

Since
  0.5.0: Works only with real modifiers
  1.8.0: Works also with virtual modifiers

## ◆ xkb_state_layout_name_is_active()

XKB_EXPORT int xkb_state_layout_name_is_active | ( | struct xkb_state * | state,
|  | const char * | name,
|  | enum xkb_state_component | type )

Test whether a layout is active in a given keyboard state by name.

Returns
  1 if the layout is active, 0 if it is not. If no layout with this name exists in the keymap, return -1.

If multiple layouts in the keymap have this name, the one with the lowest index is tested.

See also
  xkb_layout_index_t

## ◆ xkb_state_layout_index_is_active()

XKB_EXPORT int xkb_state_layout_index_is_active | ( | struct xkb_state * | state,
|  | xkb_layout_index_t | idx,
|  | enum xkb_state_component | type )

Test whether a layout is active in a given keyboard state by index.

Returns
  1 if the layout is active, 0 if it is not. If the layout index is not valid in the keymap, returns -1.

See also
  xkb_layout_index_t

## ◆ xkb_state_led_name_is_active()

XKB_EXPORT int xkb_state_led_name_is_active | ( | struct xkb_state * | state,
|  | const char * | name )

Test whether a LED is active in a given keyboard state by name.

Returns
  1 if the LED is active, 0 if it not. If no LED with this name exists in the keymap, returns -1.

See also
  xkb_led_index_t

## ◆ xkb_state_led_index_is_active()

XKB_EXPORT int xkb_state_led_index_is_active | ( | struct xkb_state * | state,
|  | xkb_led_index_t | idx )

Test whether a LED is active in a given keyboard state by index.

Returns
  1 if the LED is active, 0 if it not. If the LED index is not valid in the keymap, returns -1.

See also
  xkb_led_index_t