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 /*
  * Copyright 1985, 1987, 1990, 1998  The Open Group
  * Copyright 2008  Dan Nicholson
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  * Except as contained in this notice, the names of the authors or their
  * institutions shall not be used in advertising or otherwise to promote the
  * sale, use or other dealings in this Software without prior written
  * authorization from the authors.
  */
 
 /************************************************************
  * Copyright (c) 1993 by Silicon Graphics Computer Systems, Inc.
  *
  * Permission to use, copy, modify, and distribute this
  * software and its documentation for any purpose and without
  * fee is hereby granted, provided that the above copyright
  * notice appear in all copies and that both that copyright
  * notice and this permission notice appear in supporting
  * documentation, and that the name of Silicon Graphics not be
  * used in advertising or publicity pertaining to distribution
  * of the software without specific prior written permission.
  * Silicon Graphics makes no representation about the suitability
  * of this software for any purpose. It is provided "as is"
  * without any express or implied warranty.
  *
  * SILICON GRAPHICS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
  * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
  * GRAPHICS BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION  WITH
  * THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  ********************************************************/
 
 /*
  * Copyright © 2009-2012 Daniel Stone
  * Copyright © 2012 Intel Corporation
  * Copyright © 2012 Ran Benita
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  *
  * Author: Daniel Stone <daniel@fooishbar.org>
  */
 
 #ifndef _XKBCOMMON_H_
 #define _XKBCOMMON_H_
 
 #include <stdint.h>
 #include <stdio.h>
 #include <stdarg.h>
 
 #include <xkbcommon/xkbcommon-names.h>
 #include <xkbcommon/xkbcommon-keysyms.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /**
  * @file
  * Main libxkbcommon API.
  */
 
 /**
  * @struct xkb_context
  * Opaque top level library context object.
  *
  * The context contains various general library data and state, like
  * logging level and include paths.
  *
  * Objects are created in a specific context, and multiple contexts may
  * coexist simultaneously.  Objects from different contexts are completely
  * separated and do not share any memory or state.
  */
 struct xkb_context;
 
 /**
  * @struct xkb_keymap
  * Opaque compiled keymap object.
  *
  * The keymap object holds all of the static keyboard information obtained
  * from compiling XKB files.
  *
  * A keymap is immutable after it is created (besides reference counts, etc.);
  * if you need to change it, you must create a new one.
  */
 struct xkb_keymap;
 
 /**
  * @struct xkb_state
  * Opaque keyboard state object.
  *
  * State objects contain the active state of a keyboard (or keyboards), such
  * as the currently effective layout and the active modifiers.  It acts as a
  * simple state machine, wherein key presses and releases are the input, and
  * key symbols (keysyms) are the output.
  */
 struct xkb_state;
 
 /**
  * A number used to represent a physical key on a keyboard.
  *
  * A standard PC-compatible keyboard might have 102 keys.  An appropriate
  * keymap would assign each of them a keycode, by which the user should
  * refer to the key throughout the library.
  *
  * Historically, the X11 protocol, and consequentially the XKB protocol,
  * assign only 8 bits for keycodes.  This limits the number of different
  * keys that can be used simultaneously in a single keymap to 256
  * (disregarding other limitations).  This library does not share this limit;
  * keycodes beyond 255 ('extended keycodes') are not treated specially.
  * Keymaps and applications which are compatible with X11 should not use
  * these keycodes.
  *
  * The values of specific keycodes are determined by the keymap and the
  * underlying input system.  For example, with an X11-compatible keymap
  * and Linux evdev scan codes (see linux/input.h), a fixed offset is used:
  *
  * The keymap defines a canonical name for each key, plus possible aliases.
  * Historically, the XKB protocol restricts these names to at most 4 (ASCII)
  * characters, but this library does not share this limit.
  *
  * @code
  * xkb_keycode_t keycode_A = KEY_A + 8;
  * @endcode
  *
  * @sa xkb_keycode_is_legal_ext() xkb_keycode_is_legal_x11()
  */
 typedef uint32_t xkb_keycode_t;
 
 /**
  * A number used to represent the symbols generated from a key on a keyboard.
  *
  * A key, represented by a keycode, may generate different symbols according
  * to keyboard state.  For example, on a QWERTY keyboard, pressing the key
  * labled \<A\> generates the symbol ‘a’.  If the Shift key is held, it
  * generates the symbol ‘A’.  If a different layout is used, say Greek,
  * it generates the symbol ‘α’.  And so on.
  *
  * Each such symbol is represented by a *keysym* (short for “key symbol”).
  * Note that keysyms are somewhat more general, in that they can also represent
  * some “function”, such as “Left” or “Right” for the arrow keys.  For more
  * information, see: Appendix A [“KEYSYM Encoding”][encoding] of the X Window
  * System Protocol.
  *
  * Specifically named keysyms can be found in the
  * xkbcommon/xkbcommon-keysyms.h header file.  Their name does not include
  * the `XKB_KEY_` prefix.
  *
  * Besides those, any Unicode/ISO&nbsp;10646 character in the range U+0100 to
  * U+10FFFF can be represented by a keysym value in the range 0x01000100 to
  * 0x0110FFFF.  The name of Unicode keysyms is `U<codepoint>`, e.g. `UA1B2`.
  *
  * The name of other unnamed keysyms is the hexadecimal representation of
  * their value, e.g. `0xabcd1234`.
  *
  * Keysym names are case-sensitive.
  *
  * @note **Encoding:** Keysyms are 32-bit integers with the 3 most significant
  * bits always set to zero.  See: Appendix A [“KEYSYM Encoding”][encoding] of
  * the X Window System Protocol.
  *
  * [encoding]: https://www.x.org/releases/current/doc/xproto/x11protocol.html#keysym_encoding
  *
  * @ingroup keysyms
  * @sa XKB_KEYSYM_MAX
  */
 typedef uint32_t xkb_keysym_t;
 
 /**
  * Index of a keyboard layout.
  *
  * The layout index is a state component which detemines which <em>keyboard
  * layout</em> is active.  These may be different alphabets, different key
  * arrangements, etc.
  *
  * Layout indices are consecutive.  The first layout has index 0.
  *
  * Each layout is not required to have a name, and the names are not
  * guaranteed to be unique (though they are usually provided and unique).
  * Therefore, it is not safe to use the name as a unique identifier for a
  * layout.  Layout names are case-sensitive.
  *
  * Layout names are specified in the layout's definition, for example
  * "English (US)".  These are different from the (conventionally) short names
  * which are used to locate the layout, for example "us" or "us(intl)".  These
  * names are not present in a compiled keymap.
  *
  * If the user selects layouts from a list generated from the XKB registry
  * (using libxkbregistry or directly), and this metadata is needed later on, it
  * is recommended to store it along with the keymap.
  *
  * Layouts are also called "groups" by XKB.
  *
  * @sa xkb_keymap_num_layouts() xkb_keymap_num_layouts_for_key()
  */
 typedef uint32_t xkb_layout_index_t;
 /** A mask of layout indices. */
 typedef uint32_t xkb_layout_mask_t;
 
 /**
  * Index of a shift level.
  *
  * Any key, in any layout, can have several <em>shift levels</em>.  Each
  * shift level can assign different keysyms to the key.  The shift level
  * to use is chosen according to the current keyboard state; for example,
  * if no keys are pressed, the first level may be used; if the Left Shift
  * key is pressed, the second; if Num Lock is pressed, the third; and
  * many such combinations are possible (see xkb_mod_index_t).
  *
  * Level indices are consecutive.  The first level has index 0.
  */
 typedef uint32_t xkb_level_index_t;
 
 /**
  * Index of a modifier.
  *
  * A @e modifier is a state component which changes the way keys are
  * interpreted.  A keymap defines a set of modifiers, such as Alt, Shift,
  * Num Lock or Meta, and specifies which keys may @e activate which
  * modifiers (in a many-to-many relationship, i.e. a key can activate
  * several modifiers, and a modifier may be activated by several keys.
  * Different keymaps do this differently).
  *
  * When retrieving the keysyms for a key, the active modifier set is
  * consulted; this detemines the correct shift level to use within the
  * currently active layout (see xkb_level_index_t).
  *
  * Modifier indices are consecutive.  The first modifier has index 0.
  *
  * Each modifier must have a name, and the names are unique.  Therefore, it
  * is safe to use the name as a unique identifier for a modifier.  The names
  * of some common modifiers are provided in the xkbcommon/xkbcommon-names.h
  * header file.  Modifier names are case-sensitive.
  *
  * @sa xkb_keymap_num_mods()
  */
 typedef uint32_t xkb_mod_index_t;
 /** A mask of modifier indices. */
 typedef uint32_t xkb_mod_mask_t;
 
 /**
  * Index of a keyboard LED.
  *
  * LEDs are logical objects which may be @e active or @e inactive.  They
  * typically correspond to the lights on the keyboard. Their state is
  * determined by the current keyboard state.
  *
  * LED indices are non-consecutive.  The first LED has index 0.
  *
  * Each LED must have a name, and the names are unique. Therefore,
  * it is safe to use the name as a unique identifier for a LED.  The names
  * of some common LEDs are provided in the xkbcommon/xkbcommon-names.h
  * header file.  LED names are case-sensitive.
  *
  * @warning A given keymap may specify an exact index for a given LED.
  * Therefore, LED indexing is not necessarily sequential, as opposed to
  * modifiers and layouts.  This means that when iterating over the LEDs
  * in a keymap using e.g. xkb_keymap_num_leds(), some indices might be
  * invalid.  Given such an index, functions like xkb_keymap_led_get_name()
  * will return NULL, and xkb_state_led_index_is_active() will return -1.
  *
  * LEDs are also called "indicators" by XKB.
  *
  * @sa xkb_keymap_num_leds()
  */
 typedef uint32_t xkb_led_index_t;
 /** A mask of LED indices. */
 typedef uint32_t xkb_led_mask_t;
 
 #define XKB_KEYCODE_INVALID (0xffffffff)
 #define XKB_LAYOUT_INVALID  (0xffffffff)
 #define XKB_LEVEL_INVALID   (0xffffffff)
 #define XKB_MOD_INVALID     (0xffffffff)
 #define XKB_LED_INVALID     (0xffffffff)
 
 #define XKB_KEYCODE_MAX     (0xffffffff - 1)
 
 /**
  * Maximum keysym value
  *
  * @since 1.6.0
  * @sa xkb_keysym_t
  * @ingroup keysyms
  */
 #define XKB_KEYSYM_MAX      0x1fffffff
 
 /**
  * Test whether a value is a valid extended keycode.
  * @sa xkb_keycode_t
  **/
 #define xkb_keycode_is_legal_ext(key) (key <= XKB_KEYCODE_MAX)
 
 /**
  * Test whether a value is a valid X11 keycode.
  * @sa xkb_keycode_t
  */
 #define xkb_keycode_is_legal_x11(key) (key >= 8 && key <= 255)
 
 /**
  * Names to compile a keymap with, also known as RMLVO.
  *
  * The names are the common configuration values by which a user picks
  * a keymap.
  *
  * If the entire struct is NULL, then each field is taken to be NULL.
  * You should prefer passing NULL instead of choosing your own defaults.
  */
 struct xkb_rule_names {
     /**
      * The rules file to use. The rules file describes how to interpret
      * the values of the model, layout, variant and options fields.
      *
      * If NULL or the empty string "", a default value is used.
      * If the XKB_DEFAULT_RULES environment variable is set, it is used
      * as the default.  Otherwise the system default is used.
      */
     const char *rules;
     /**
      * The keyboard model by which to interpret keycodes and LEDs.
      *
      * If NULL or the empty string "", a default value is used.
      * If the XKB_DEFAULT_MODEL environment variable is set, it is used
      * as the default.  Otherwise the system default is used.
      */
     const char *model;
     /**
      * A comma separated list of layouts (languages) to include in the
      * keymap.
      *
      * If NULL or the empty string "", a default value is used.
      * If the XKB_DEFAULT_LAYOUT environment variable is set, it is used
      * as the default.  Otherwise the system default is used.
      */
     const char *layout;
     /**
      * A comma separated list of variants, one per layout, which may
      * modify or augment the respective layout in various ways.
      *
      * Generally, should either be empty or have the same number of values
      * as the number of layouts. You may use empty values as in "intl,,neo".
      *
      * If NULL or the empty string "", and a default value is also used
      * for the layout, a default value is used.  Otherwise no variant is
      * used.
      * If the XKB_DEFAULT_VARIANT environment variable is set, it is used
      * as the default.  Otherwise the system default is used.
      */
     const char *variant;
     /**
      * A comma separated list of options, through which the user specifies
      * non-layout related preferences, like which key combinations are used
      * for switching layouts, or which key is the Compose key.
      *
      * If NULL, a default value is used.  If the empty string "", no
      * options are used.
      * If the XKB_DEFAULT_OPTIONS environment variable is set, it is used
      * as the default.  Otherwise the system default is used.
      */
     const char *options;
 };
 
 /**
  * @defgroup keysyms Keysyms
  * Utility functions related to *keysyms* (short for “key symbols”).
  *
  * @{
  */
 
 /**
  * @page keysym-transformations Keysym Transformations
  *
  * Keysym translation is subject to several "keysym transformations",
  * as described in the XKB specification.  These are:
  *
  * - Capitalization transformation.  If the Caps Lock modifier is
  *   active and was not consumed by the translation process, a single
  *   keysym is transformed to its upper-case form (if applicable).
  *   Similarly, the UTF-8/UTF-32 string produced is capitalized.
  *
  *   This is described in:
  *   https://www.x.org/releases/current/doc/kbproto/xkbproto.html#Interpreting_the_Lock_Modifier
  *
  * - Control transformation.  If the Control modifier is active and
  *   was not consumed by the translation process, the string produced
  *   is transformed to its matching ASCII control character (if
  *   applicable).  Keysyms are not affected.
  *
  *   This is described in:
  *   https://www.x.org/releases/current/doc/kbproto/xkbproto.html#Interpreting_the_Control_Modifier
  *
  * Each relevant function discusses which transformations it performs.
  *
  * These transformations are not applicable when a key produces multiple
  * keysyms.
  */
 
 
 /**
  * Get the name of a keysym.
  *
  * For a description of how keysyms are named, see @ref xkb_keysym_t.
  *
  * @param[in]  keysym The keysym.
  * @param[out] buffer A string buffer to write the name into.
  * @param[in]  size   Size of the buffer.
  *
  * @warning If the buffer passed is too small, the string is truncated
  * (though still NUL-terminated); a size of at least 64 bytes is recommended.
  *
  * @returns The number of bytes in the name, excluding the NUL byte. If
  * the keysym is invalid, returns -1.
  *
  * You may check if truncation has occurred by comparing the return value
  * with the length of buffer, similarly to the snprintf(3) function.
  *
  * @sa xkb_keysym_t
  */
 int
 xkb_keysym_get_name(xkb_keysym_t keysym, char *buffer, size_t size);
 
 /** Flags for xkb_keysym_from_name(). */
 enum xkb_keysym_flags {
     /** Do not apply any flags. */
     XKB_KEYSYM_NO_FLAGS = 0,
     /** Find keysym by case-insensitive search. */
     XKB_KEYSYM_CASE_INSENSITIVE = (1 << 0)
 };
 
 /**
  * Get a keysym from its name.
  *
  * @param name The name of a keysym. See remarks in xkb_keysym_get_name();
  * this function will accept any name returned by that function.
  * @param flags A set of flags controlling how the search is done. If
  * invalid flags are passed, this will fail with XKB_KEY_NoSymbol.
  *
  * If you use the XKB_KEYSYM_CASE_INSENSITIVE flag and two keysym names
  * differ only by case, then the lower-case keysym name is returned.  For
  * instance, for KEY_a and KEY_A, this function would return KEY_a for the
  * case-insensitive search.  If this functionality is needed, it is
  * recommended to first call this function without this flag; and if that
  * fails, only then to try with this flag, while possibly warning the user
  * he had misspelled the name, and might get wrong results.
  *
  * Case folding is done according to the C locale; the current locale is not
  * consulted.
  *
  * @returns The keysym. If the name is invalid, returns XKB_KEY_NoSymbol.
  *
  * @sa xkb_keysym_t
  */
 xkb_keysym_t
 xkb_keysym_from_name(const char *name, enum xkb_keysym_flags flags);
 
 /**
  * Get the Unicode/UTF-8 representation of a keysym.
  *
  * @param[in]  keysym The keysym.
  * @param[out] buffer A buffer to write the UTF-8 string into.
  * @param[in]  size   The size of buffer.  Must be at least 7.
  *
  * @returns The number of bytes written to the buffer (including the
  * terminating byte).  If the keysym does not have a Unicode
  * representation, returns 0.  If the buffer is too small, returns -1.
  *
  * This function does not perform any @ref keysym-transformations.
  * Therefore, prefer to use xkb_state_key_get_utf8() if possible.
  *
  * @sa xkb_state_key_get_utf8()
  */
 int
 xkb_keysym_to_utf8(xkb_keysym_t keysym, char *buffer, size_t size);
 
 /**
  * Get the Unicode/UTF-32 representation of a keysym.
  *
  * @returns The Unicode/UTF-32 representation of keysym, which is also
  * compatible with UCS-4.  If the keysym does not have a Unicode
  * representation, returns 0.
  *
  * This function does not perform any @ref keysym-transformations.
  * Therefore, prefer to use xkb_state_key_get_utf32() if possible.
  *
  * @sa xkb_state_key_get_utf32()
  */
 uint32_t
 xkb_keysym_to_utf32(xkb_keysym_t keysym);
 
 /**
  * Get the keysym corresponding to a Unicode/UTF-32 codepoint.
  *
  * @returns The keysym corresponding to the specified Unicode
  * codepoint, or XKB_KEY_NoSymbol if there is none.
  *
  * This function is the inverse of @ref xkb_keysym_to_utf32. In cases
  * where a single codepoint corresponds to multiple keysyms, returns
  * the keysym with the lowest value.
  *
  * Unicode codepoints which do not have a special (legacy) keysym
  * encoding use a direct encoding scheme. These keysyms don't usually
  * have an associated keysym constant (XKB_KEY_*).
  *
  * For noncharacter Unicode codepoints and codepoints outside of the
  * defined Unicode planes this function returns XKB_KEY_NoSymbol.
  *
  * @sa xkb_keysym_to_utf32()
  * @since 1.0.0
  */
 xkb_keysym_t
 xkb_utf32_to_keysym(uint32_t ucs);
 
 /**
  * Convert a keysym to its uppercase form.
  *
  * If there is no such form, the keysym is returned unchanged.
  *
  * The conversion rules may be incomplete; prefer to work with the Unicode
  * representation instead, when possible.
  */
 xkb_keysym_t
 xkb_keysym_to_upper(xkb_keysym_t ks);
 
 /**
  * Convert a keysym to its lowercase form.
  *
  * The conversion rules may be incomplete; prefer to work with the Unicode
  * representation instead, when possible.
  */
 xkb_keysym_t
 xkb_keysym_to_lower(xkb_keysym_t ks);
 
 /** @} */
 
 /**
  * @defgroup context Library Context
  * Creating, destroying and using library contexts.
  *
  * Every keymap compilation request must have a context associated with
  * it.  The context keeps around state such as the include path.
  *
  * @{
  */
 
 /**
  * @page envvars Environment Variables
  *
  * The user may set some environment variables which affect the library:
  *
  * - `XKB_CONFIG_ROOT`, `XKB_CONFIG_EXTRA_PATH`, `XDG_CONFIG_DIR`, `HOME` - see @ref include-path.
  * - `XKB_LOG_LEVEL` - see xkb_context_set_log_level().
  * - `XKB_LOG_VERBOSITY` - see xkb_context_set_log_verbosity().
  * - `XKB_DEFAULT_RULES`, `XKB_DEFAULT_MODEL`, `XKB_DEFAULT_LAYOUT`,
  *   `XKB_DEFAULT_VARIANT`, `XKB_DEFAULT_OPTIONS` - see xkb_rule_names.
  */
 
 /** Flags for context creation. */
 enum xkb_context_flags {
     /** Do not apply any context flags. */
     XKB_CONTEXT_NO_FLAGS = 0,
     /** Create this context with an empty include path. */
     XKB_CONTEXT_NO_DEFAULT_INCLUDES = (1 << 0),
     /**
      * Don't take RMLVO names from the environment.
      *
      * @since 0.3.0
      */
     XKB_CONTEXT_NO_ENVIRONMENT_NAMES = (1 << 1),
     /**
      * Disable the use of secure_getenv for this context, so that privileged
      * processes can use environment variables. Client uses at their own risk.
      *
      * @since 1.5.0
      */
     XKB_CONTEXT_NO_SECURE_GETENV = (1 << 2)
 };
 
 /**
  * Create a new context.
  *
  * @param flags Optional flags for the context, or 0.
  *
  * @returns A new context, or NULL on failure.
  *
  * @memberof xkb_context
  */
 struct xkb_context *
 xkb_context_new(enum xkb_context_flags flags);
 
 /**
  * Take a new reference on a context.
  *
  * @returns The passed in context.
  *
  * @memberof xkb_context
  */
 struct xkb_context *
 xkb_context_ref(struct xkb_context *context);
 
 /**
  * Release a reference on a context, and possibly free it.
  *
  * @param context The context.  If it is NULL, this function does nothing.
  *
  * @memberof xkb_context
  */
 void
 xkb_context_unref(struct xkb_context *context);
 
 /**
  * Store custom user data in the context.
  *
  * This may be useful in conjunction with xkb_context_set_log_fn() or other
  * callbacks.
  *
  * @memberof xkb_context
  */
 void
 xkb_context_set_user_data(struct xkb_context *context, void *user_data);
 
 /**
  * Retrieves stored user data from the context.
  *
  * @returns The stored user data.  If the user data wasn't set, or the
  * passed in context is NULL, returns NULL.
  *
  * This may be useful to access private user data from callbacks like a
  * custom logging function.
  *
  * @memberof xkb_context
  **/
 void *
 xkb_context_get_user_data(struct xkb_context *context);
 
 /** @} */
 
 /**
  * @defgroup include-path Include Paths
  * Manipulating the include paths in a context.
  *
  * The include paths are the file-system paths that are searched when an
  * include statement is encountered during keymap compilation.
  *
  * The default include paths are, in that lookup order:
  * - The path `$XDG_CONFIG_HOME/xkb`, with the usual `XDG_CONFIG_HOME`
  *   fallback to `$HOME/.config/` if unset.
  * - The path `$HOME/.xkb`, where $HOME is the value of the environment
  *   variable `HOME`.
  * - The `XKB_CONFIG_EXTRA_PATH` environment variable, if defined, otherwise the
  *   system configuration directory, defined at library configuration time
  *   (usually `/etc/xkb`).
  * - The `XKB_CONFIG_ROOT` environment variable, if defined, otherwise
  *   the system XKB root, defined at library configuration time.
  *
  * @{
  */
 
 /**
  * Append a new entry to the context's include path.
  *
  * @returns 1 on success, or 0 if the include path could not be added or is
  * inaccessible.
  *
  * @memberof xkb_context
  */
 int
 xkb_context_include_path_append(struct xkb_context *context, const char *path);
 
 /**
  * Append the default include paths to the context's include path.
  *
  * @returns 1 on success, or 0 if the primary include path could not be added.
  *
  * @memberof xkb_context
  */
 int
 xkb_context_include_path_append_default(struct xkb_context *context);
 
 /**
  * Reset the context's include path to the default.
  *
  * Removes all entries from the context's include path, and inserts the
  * default paths.
  *
  * @returns 1 on success, or 0 if the primary include path could not be added.
  *
  * @memberof xkb_context
  */
 int
 xkb_context_include_path_reset_defaults(struct xkb_context *context);
 
 /**
  * Remove all entries from the context's include path.
  *
  * @memberof xkb_context
  */
 void
 xkb_context_include_path_clear(struct xkb_context *context);
 
 /**
  * Get the number of paths in the context's include path.
  *
  * @memberof xkb_context
  */
 unsigned int
 xkb_context_num_include_paths(struct xkb_context *context);
 
 /**
  * Get a specific include path from the context's include path.
  *
  * @returns The include path at the specified index.  If the index is
  * invalid, returns NULL.
  *
  * @memberof xkb_context
  */
 const char *
 xkb_context_include_path_get(struct xkb_context *context, unsigned int index);
 
 /** @} */
 
 /**
  * @defgroup logging Logging Handling
  * Manipulating how logging from this library is handled.
  *
  * @{
  */
 
 /** Specifies a logging level. */
 enum xkb_log_level {
     XKB_LOG_LEVEL_CRITICAL = 10, /**< Log critical internal errors only. */
     XKB_LOG_LEVEL_ERROR = 20,    /**< Log all errors. */
     XKB_LOG_LEVEL_WARNING = 30,  /**< Log warnings and errors. */
     XKB_LOG_LEVEL_INFO = 40,     /**< Log information, warnings, and errors. */
     XKB_LOG_LEVEL_DEBUG = 50     /**< Log everything. */
 };
 
 /**
  * Set the current logging level.
  *
  * @param context The context in which to set the logging level.
  * @param level   The logging level to use.  Only messages from this level
  * and below will be logged.
  *
  * The default level is XKB_LOG_LEVEL_ERROR.  The environment variable
  * XKB_LOG_LEVEL, if set in the time the context was created, overrides the
  * default value.  It may be specified as a level number or name.
  *
  * @memberof xkb_context
  */
 void
 xkb_context_set_log_level(struct xkb_context *context,
                           enum xkb_log_level level);
 
 /**
  * Get the current logging level.
  *
  * @memberof xkb_context
  */
 enum xkb_log_level
 xkb_context_get_log_level(struct xkb_context *context);
 
 /**
  * Sets the current logging verbosity.
  *
  * The library can generate a number of warnings which are not helpful to
  * ordinary users of the library.  The verbosity may be increased if more
  * information is desired (e.g. when developing a new keymap).
  *
  * The default verbosity is 0.  The environment variable XKB_LOG_VERBOSITY,
  * if set in the time the context was created, overrides the default value.
  *
  * @param context   The context in which to use the set verbosity.
  * @param verbosity The verbosity to use.  Currently used values are
  * 1 to 10, higher values being more verbose.  0 would result in no verbose
  * messages being logged.
  *
  * Most verbose messages are of level XKB_LOG_LEVEL_WARNING or lower.
  *
  * @memberof xkb_context
  */
 void
 xkb_context_set_log_verbosity(struct xkb_context *context, int verbosity);
 
 /**
  * Get the current logging verbosity of the context.
  *
  * @memberof xkb_context
  */
 int
 xkb_context_get_log_verbosity(struct xkb_context *context);
 
 /**
  * Set a custom function to handle logging messages.
  *
  * @param context The context in which to use the set logging function.
  * @param log_fn  The function that will be called for logging messages.
  * Passing NULL restores the default function, which logs to stderr.
  *
  * By default, log messages from this library are printed to stderr.  This
  * function allows you to replace the default behavior with a custom
  * handler.  The handler is only called with messages which match the
  * current logging level and verbosity settings for the context.
  * level is the logging level of the message.  @a format and @a args are
  * the same as in the vprintf(3) function.
  *
  * You may use xkb_context_set_user_data() on the context, and then call
  * xkb_context_get_user_data() from within the logging function to provide
  * it with additional private context.
  *
  * @memberof xkb_context
  */
 void
 xkb_context_set_log_fn(struct xkb_context *context,
                        void (*log_fn)(struct xkb_context *context,
                                       enum xkb_log_level level,
                                       const char *format, va_list args));
 
 /** @} */
 
 /**
  * @defgroup keymap Keymap Creation
  * Creating and destroying keymaps.
  *
  * @{
  */
 
 /** Flags for keymap compilation. */
 enum xkb_keymap_compile_flags {
     /** Do not apply any flags. */
     XKB_KEYMAP_COMPILE_NO_FLAGS = 0
 };
 
 /**
  * Create a keymap from RMLVO names.
  *
  * The primary keymap entry point: creates a new XKB keymap from a set of
  * RMLVO (Rules + Model + Layouts + Variants + Options) names.
  *
  * @param context The context in which to create the keymap.
  * @param names   The RMLVO names to use.  See xkb_rule_names.
  * @param flags   Optional flags for the keymap, or 0.
  *
  * @returns A keymap compiled according to the RMLVO names, or NULL if
  * the compilation failed.
  *
  * @sa xkb_rule_names
  * @memberof xkb_keymap
  */
 struct xkb_keymap *
 xkb_keymap_new_from_names(struct xkb_context *context,
                           const struct xkb_rule_names *names,
                           enum xkb_keymap_compile_flags flags);
 
 /** The possible keymap formats. */
 enum xkb_keymap_format {
     /** The current/classic XKB text format, as generated by xkbcomp -xkb. */
     XKB_KEYMAP_FORMAT_TEXT_V1 = 1
 };
 
 /**
  * Create a keymap from a keymap file.
  *
  * @param context The context in which to create the keymap.
  * @param file    The keymap file to compile.
  * @param format  The text format of the keymap file to compile.
  * @param flags   Optional flags for the keymap, or 0.
  *
  * @returns A keymap compiled from the given XKB keymap file, or NULL if
  * the compilation failed.
  *
  * The file must contain a complete keymap.  For example, in the
  * XKB_KEYMAP_FORMAT_TEXT_V1 format, this means the file must contain one
  * top level '%xkb_keymap' section, which in turn contains other required
  * sections.
  *
  * @memberof xkb_keymap
  */
 struct xkb_keymap *
 xkb_keymap_new_from_file(struct xkb_context *context, FILE *file,
                          enum xkb_keymap_format format,
                          enum xkb_keymap_compile_flags flags);
 
 /**
  * Create a keymap from a keymap string.
  *
  * This is just like xkb_keymap_new_from_file(), but instead of a file, gets
  * the keymap as one enormous string.
  *
  * @see xkb_keymap_new_from_file()
  * @memberof xkb_keymap
  */
 struct xkb_keymap *
 xkb_keymap_new_from_string(struct xkb_context *context, const char *string,
                            enum xkb_keymap_format format,
                            enum xkb_keymap_compile_flags flags);
 
 /**
  * Create a keymap from a memory buffer.
  *
  * This is just like xkb_keymap_new_from_string(), but takes a length argument
  * so the input string does not have to be zero-terminated.
  *
  * @see xkb_keymap_new_from_string()
  * @memberof xkb_keymap
  * @since 0.3.0
  */
 struct xkb_keymap *
 xkb_keymap_new_from_buffer(struct xkb_context *context, const char *buffer,
                            size_t length, enum xkb_keymap_format format,
                            enum xkb_keymap_compile_flags flags);
 
 /**
  * Take a new reference on a keymap.
  *
  * @returns The passed in keymap.
  *
  * @memberof xkb_keymap
  */
 struct xkb_keymap *
 xkb_keymap_ref(struct xkb_keymap *keymap);
 
 /**
  * Release a reference on a keymap, and possibly free it.
  *
  * @param keymap The keymap.  If it is NULL, this function does nothing.
  *
  * @memberof xkb_keymap
  */
 void
 xkb_keymap_unref(struct xkb_keymap *keymap);
 
 /**
  * Get the keymap as a string in the format from which it was created.
  * @sa xkb_keymap_get_as_string()
  **/
 #define XKB_KEYMAP_USE_ORIGINAL_FORMAT ((enum xkb_keymap_format) -1)
 
 /**
  * Get the compiled keymap as a string.
  *
  * @param keymap The keymap to get as a string.
  * @param format The keymap format to use for the string.  You can pass
  * in the special value XKB_KEYMAP_USE_ORIGINAL_FORMAT to use the format
  * from which the keymap was originally created.
  *
  * @returns The keymap as a NUL-terminated string, or NULL if unsuccessful.
  *
  * The returned string may be fed back into xkb_keymap_new_from_string() to get
  * the exact same keymap (possibly in another process, etc.).
  *
  * The returned string is dynamically allocated and should be freed by the
  * caller.
  *
  * @memberof xkb_keymap
  */
 char *
 xkb_keymap_get_as_string(struct xkb_keymap *keymap,
                          enum xkb_keymap_format format);
 
 /** @} */
 
 /**
  * @defgroup components Keymap Components
  * Enumeration of state components in a keymap.
  *
  * @{
  */
 
 /**
  * Get the minimum keycode in the keymap.
  *
  * @sa xkb_keycode_t
  * @memberof xkb_keymap
  * @since 0.3.1
  */
 xkb_keycode_t
 xkb_keymap_min_keycode(struct xkb_keymap *keymap);
 
 /**
  * Get the maximum keycode in the keymap.
  *
  * @sa xkb_keycode_t
  * @memberof xkb_keymap
  * @since 0.3.1
  */
 xkb_keycode_t
 xkb_keymap_max_keycode(struct xkb_keymap *keymap);
 
 /**
  * The iterator used by xkb_keymap_key_for_each().
  *
  * @sa xkb_keymap_key_for_each
  * @memberof xkb_keymap
  * @since 0.3.1
  */
 typedef void
 (*xkb_keymap_key_iter_t)(struct xkb_keymap *keymap, xkb_keycode_t key,
                          void *data);
 
 /**
  * Run a specified function for every valid keycode in the keymap.  If a
  * keymap is sparse, this function may be called fewer than
  * (max_keycode - min_keycode + 1) times.
  *
  * @sa xkb_keymap_min_keycode() xkb_keymap_max_keycode() xkb_keycode_t
  * @memberof xkb_keymap
  * @since 0.3.1
  */
 void
 xkb_keymap_key_for_each(struct xkb_keymap *keymap, xkb_keymap_key_iter_t iter,
                         void *data);
 
 /**
  * Find the name of the key with the given keycode.
  *
  * This function always returns the canonical name of the key (see
  * description in xkb_keycode_t).
  *
  * @returns The key name. If no key with this keycode exists,
  * returns NULL.
  *
  * @sa xkb_keycode_t
  * @memberof xkb_keymap
  * @since 0.6.0
  */
 const char *
 xkb_keymap_key_get_name(struct xkb_keymap *keymap, xkb_keycode_t key);
 
 /**
  * Find the keycode of the key with the given name.
  *
  * The name can be either a canonical name or an alias.
  *
  * @returns The keycode. If no key with this name exists,
  * returns XKB_KEYCODE_INVALID.
  *
  * @sa xkb_keycode_t
  * @memberof xkb_keymap
  * @since 0.6.0
  */
 xkb_keycode_t
 xkb_keymap_key_by_name(struct xkb_keymap *keymap, const char *name);
 
 /**
  * Get the number of modifiers in the keymap.
  *
  * @sa xkb_mod_index_t
  * @memberof xkb_keymap
  */
 xkb_mod_index_t
 xkb_keymap_num_mods(struct xkb_keymap *keymap);
 
 /**
  * Get the name of a modifier by index.
  *
  * @returns The name.  If the index is invalid, returns NULL.
  *
  * @sa xkb_mod_index_t
  * @memberof xkb_keymap
  */
 const char *
 xkb_keymap_mod_get_name(struct xkb_keymap *keymap, xkb_mod_index_t idx);
 
 /**
  * Get the index of a modifier by name.
  *
  * @returns The index.  If no modifier with this name exists, returns
  * XKB_MOD_INVALID.
  *
  * @sa xkb_mod_index_t
  * @memberof xkb_keymap
  */
 xkb_mod_index_t
 xkb_keymap_mod_get_index(struct xkb_keymap *keymap, const char *name);
 
 /**
  * Get the number of layouts in the keymap.
  *
  * @sa xkb_layout_index_t xkb_rule_names xkb_keymap_num_layouts_for_key()
  * @memberof xkb_keymap
  */
 xkb_layout_index_t
 xkb_keymap_num_layouts(struct xkb_keymap *keymap);
 
 /**
  * Get the name of a layout by index.
  *
  * @returns The name.  If the index is invalid, or the layout does not have
  * a name, returns NULL.
  *
  * @sa xkb_layout_index_t
  *     For notes on layout names.
  * @memberof xkb_keymap
  */
 const char *
 xkb_keymap_layout_get_name(struct xkb_keymap *keymap, xkb_layout_index_t idx);
 
 /**
  * Get the index of a layout by name.
  *
  * @returns The index.  If no layout exists with this name, returns
  * XKB_LAYOUT_INVALID.  If more than one layout in the keymap has this name,
  * returns the lowest index among them.
  *
  * @sa xkb_layout_index_t
  *     For notes on layout names.
  * @memberof xkb_keymap
  */
 xkb_layout_index_t
 xkb_keymap_layout_get_index(struct xkb_keymap *keymap, const char *name);
 
 /**
  * Get the number of LEDs in the keymap.
  *
  * @warning The range [ 0...xkb_keymap_num_leds() ) includes all of the LEDs
  * in the keymap, but may also contain inactive LEDs.  When iterating over
  * this range, you need the handle this case when calling functions such as
  * xkb_keymap_led_get_name() or xkb_state_led_index_is_active().
  *
  * @sa xkb_led_index_t
  * @memberof xkb_keymap
  */
 xkb_led_index_t
 xkb_keymap_num_leds(struct xkb_keymap *keymap);
 
 /**
  * Get the name of a LED by index.
  *
  * @returns The name.  If the index is invalid, returns NULL.
  *
  * @memberof xkb_keymap
  */
 const char *
 xkb_keymap_led_get_name(struct xkb_keymap *keymap, xkb_led_index_t idx);
 
 /**
  * Get the index of a LED by name.
  *
  * @returns The index.  If no LED with this name exists, returns
  * XKB_LED_INVALID.
  *
  * @memberof xkb_keymap
  */
 xkb_led_index_t
 xkb_keymap_led_get_index(struct xkb_keymap *keymap, const char *name);
 
 /**
  * Get the number of layouts for a specific key.
  *
  * This number can be different from xkb_keymap_num_layouts(), but is always
  * smaller.  It is the appropriate value to use when iterating over the
  * layouts of a key.
  *
  * @sa xkb_layout_index_t
  * @memberof xkb_keymap
  */
 xkb_layout_index_t
 xkb_keymap_num_layouts_for_key(struct xkb_keymap *keymap, xkb_keycode_t key);
 
 /**
  * Get the number of shift levels for a specific key and layout.
  *
  * If @c layout is out of range for this key (that is, larger or equal to
  * the value returned by xkb_keymap_num_layouts_for_key()), it is brought
  * back into range in a manner consistent with xkb_state_key_get_layout().
  *
  * @sa xkb_level_index_t
  * @memberof xkb_keymap
  */
 xkb_level_index_t
 xkb_keymap_num_levels_for_key(struct xkb_keymap *keymap, xkb_keycode_t key,
                               xkb_layout_index_t layout);
 
 /**
  * Retrieves every possible modifier mask that produces the specified
  * shift level for a specific key and layout.
  *
  * This API is useful for inverse key transformation; i.e. finding out
  * which modifiers need to be active in order to be able to type the
  * keysym(s) corresponding to the specific key code, layout and level.
  *
  * @warning It returns only up to masks_size modifier masks. If the
  * buffer passed is too small, some of the possible modifier combinations
  * will not be returned.
  *
  * @param[in] keymap      The keymap.
  * @param[in] key         The keycode of the key.
  * @param[in] layout      The layout for which to get modifiers.
  * @param[in] level       The shift level in the layout for which to get the
  * modifiers. This should be smaller than:
  * @code xkb_keymap_num_levels_for_key(keymap, key) @endcode
  * @param[out] masks_out  A buffer in which the requested masks should be
  * stored.
  * @param[out] masks_size The number of elements in the buffer pointed to by
  * masks_out.
  *
  * If @c layout is out of range for this key (that is, larger or equal to
  * the value returned by xkb_keymap_num_layouts_for_key()), it is brought
  * back into range in a manner consistent with xkb_state_key_get_layout().
  *
  * @returns The number of modifier masks stored in the masks_out array.
  * If the key is not in the keymap or if the specified shift level cannot
  * be reached it returns 0 and does not modify the masks_out buffer.
  *
  * @sa xkb_level_index_t
  * @sa xkb_mod_mask_t
  * @memberof xkb_keymap
  * @since 1.0.0
  */
 size_t
 xkb_keymap_key_get_mods_for_level(struct xkb_keymap *keymap,
                                   xkb_keycode_t key,
                                   xkb_layout_index_t layout,
                                   xkb_level_index_t level,
                                   xkb_mod_mask_t *masks_out,
                                   size_t masks_size);
 
 /**
  * Get the keysyms obtained from pressing a key in a given layout and
  * shift level.
  *
  * This function is like xkb_state_key_get_syms(), only the layout and
  * shift level are not derived from the keyboard state but are instead
  * specified explicitly.
  *
  * @param[in] keymap    The keymap.
  * @param[in] key       The keycode of the key.
  * @param[in] layout    The layout for which to get the keysyms.
  * @param[in] level     The shift level in the layout for which to get the
  * keysyms. This should be smaller than:
  * @code xkb_keymap_num_levels_for_key(keymap, key) @endcode
  * @param[out] syms_out An immutable array of keysyms corresponding to the
  * key in the given layout and shift level.
  *
  * If @c layout is out of range for this key (that is, larger or equal to
  * the value returned by xkb_keymap_num_layouts_for_key()), it is brought
  * back into range in a manner consistent with xkb_state_key_get_layout().
  *
  * @returns The number of keysyms in the syms_out array.  If no keysyms
  * are produced by the key in the given layout and shift level, returns 0
  * and sets syms_out to NULL.
  *
  * @sa xkb_state_key_get_syms()
  * @memberof xkb_keymap
  */
 int
 xkb_keymap_key_get_syms_by_level(struct xkb_keymap *keymap,
                                  xkb_keycode_t key,
                                  xkb_layout_index_t layout,
                                  xkb_level_index_t level,
                                  const xkb_keysym_t **syms_out);
 
 /**
  * Determine whether a key should repeat or not.
  *
  * A keymap may specify different repeat behaviors for different keys.
  * Most keys should generally exhibit repeat behavior; for example, holding
  * the 'a' key down in a text editor should normally insert a single 'a'
  * character every few milliseconds, until the key is released.  However,
  * there are keys which should not or do not need to be repeated.  For
  * example, repeating modifier keys such as Left/Right Shift or Caps Lock
  * is not generally useful or desired.
  *
  * @returns 1 if the key should repeat, 0 otherwise.
  *
  * @memberof xkb_keymap
  */
 int
 xkb_keymap_key_repeats(struct xkb_keymap *keymap, xkb_keycode_t key);
 
 /** @} */
 
 /**
  * @defgroup state Keyboard State
  * Creating, destroying and manipulating keyboard state objects.
  *
  * @{
  */
 
 /**
  * Create a new keyboard state object.
  *
  * @param keymap The keymap which the state will use.
  *
  * @returns A new keyboard state object, or NULL on failure.
  *
  * @memberof xkb_state
  */
 struct xkb_state *
 xkb_state_new(struct xkb_keymap *keymap);
 
 /**
  * Take a new reference on a keyboard state object.
  *
  * @returns The passed in object.
  *
  * @memberof xkb_state
  */
 struct xkb_state *
 xkb_state_ref(struct xkb_state *state);
 
 /**
  * Release a reference on a keybaord state object, and possibly free it.
  *
  * @param state The state.  If it is NULL, this function does nothing.
  *
  * @memberof xkb_state
  */
 void
 xkb_state_unref(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.
  *
  * @memberof xkb_state
  */
 struct xkb_keymap *
 xkb_state_get_keymap(struct xkb_state *state);
 
 /**
  * @page server-client-state Server State and Client State
  * @parblock
  *
  * 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.
  *
  * @endparblock
  */
 
 /** Specifies the direction of the key (press / release). */
 enum xkb_key_direction {
     XKB_KEY_UP,   /**< The key was released. */
     XKB_KEY_DOWN  /**< The key was pressed. */
 };
 
 /**
  * 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'.
  */
 enum xkb_state_component {
     /** Depressed modifiers, i.e. a key is physically holding them. */
     XKB_STATE_MODS_DEPRESSED = (1 << 0),
     /** Latched modifiers, i.e. will be unset after the next non-modifier
      *  key press. */
     XKB_STATE_MODS_LATCHED = (1 << 1),
     /** Locked modifiers, i.e. will be unset after the key provoking the
      *  lock has been pressed again. */
     XKB_STATE_MODS_LOCKED = (1 << 2),
     /** 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_MODS_EFFECTIVE = (1 << 3),
     /** Depressed layout, i.e. a key is physically holding it. */
     XKB_STATE_LAYOUT_DEPRESSED = (1 << 4),
     /** Latched layout, i.e. will be unset after the next non-modifier
      *  key press. */
     XKB_STATE_LAYOUT_LATCHED = (1 << 5),
     /** Locked layout, i.e. will be unset after the key provoking the lock
      *  has been pressed again. */
     XKB_STATE_LAYOUT_LOCKED = (1 << 6),
     /** 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_LAYOUT_EFFECTIVE = (1 << 7),
     /** LEDs (derived from the other state components). */
     XKB_STATE_LEDS = (1 << 8)
 };
 
 /**
  * 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 @ref server-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.
  *
  * @memberof xkb_state
  *
  * @sa xkb_state_update_mask()
  */
 enum xkb_state_component
 xkb_state_update_key(struct xkb_state *state, xkb_keycode_t key,
                      enum xkb_key_direction direction);
 
 /**
  * Update a keyboard state from a set of explicit masks.
  *
  * This entry point is intended for *client* applications; see @ref
  * server-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.
  *
  * 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.
  *
  * @memberof xkb_state
  *
  * @sa xkb_state_component
  * @sa xkb_state_update_key
  */
 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);
 
 /**
  * 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.
  *
  * @param[in]  state    The keyboard state object.
  * @param[in]  key      The keycode of the key.
  * @param[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.
  *
  * This function does not perform any @ref keysym-transformations.
  * (This might change).
  *
  * @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.
  *
  * @memberof xkb_state
  */
 int
 xkb_state_key_get_syms(struct xkb_state *state, xkb_keycode_t key,
                        const xkb_keysym_t **syms_out);
 
 /**
  * Get the Unicode/UTF-8 string obtained from pressing a particular key
  * in a given keyboard state.
  *
  * @param[in]  state  The keyboard state object.
  * @param[in]  key    The keycode of the key.
  * @param[out] buffer A buffer to write the string into.
  * @param[in]  size   Size of the buffer.
  *
  * @warning If the buffer passed is too small, the string is truncated
  * (though still NUL-terminated).
  *
  * @returns The number of bytes required for the string, excluding the
  * NUL 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 @p buffer, similarly to the snprintf(3) function.
  * You may safely pass NULL and 0 to @p buffer and @p size to find the
  * required size (without the NUL-byte).
  *
  * This function performs Capitalization and Control @ref
  * keysym-transformations.
  *
  * @memberof xkb_state
  * @since 0.4.1
  */
 int
 xkb_state_key_get_utf8(struct xkb_state *state, xkb_keycode_t key,
                        char *buffer, size_t size);
 
 /**
  * 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 @ref
  * keysym-transformations.
  *
  * @memberof xkb_state
  * @since 0.4.1
  */
 uint32_t
 xkb_state_key_get_utf32(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 @ref keysym-transformations.
  *
  * @sa xkb_state_key_get_syms()
  * @memberof xkb_state
  */
 xkb_keysym_t
 xkb_state_key_get_one_sym(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:
  * @code
  * xkb_state_key_get_layout(state, key) < xkb_keymap_num_layouts_for_key(keymap, key)
  * @endcode
  *
  * @memberof xkb_state
  */
 xkb_layout_index_t
 xkb_state_key_get_layout(struct xkb_state *state, xkb_keycode_t key);
 
 /**
  * Get the effective shift level for a key in a given keyboard state and
  * layout.
  *
  * @param state The keyboard state.
  * @param key The keycode of the key.
  * @param layout The layout for which to get the shift level.  This must be
  * smaller than:
  * @code xkb_keymap_num_layouts_for_key(keymap, key) @endcode
  * usually it would be:
  * @code xkb_state_key_get_layout(state, key) @endcode
  *
  * @return 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:
  * @code
  * xkb_state_key_get_level(state, key, layout) < xkb_keymap_num_levels_for_key(keymap, key, layout)
  * @endcode
  *
  * @memberof xkb_state
  */
 xkb_level_index_t
 xkb_state_key_get_level(struct xkb_state *state, xkb_keycode_t key,
                         xkb_layout_index_t layout);
 
 /**
  * Match flags for xkb_state_mod_indices_are_active() and
  * xkb_state_mod_names_are_active(), specifying the conditions for a
  * successful match.  XKB_STATE_MATCH_NON_EXCLUSIVE is bitmaskable with
  * the other modes.
  */
 enum xkb_state_match {
     /** Returns true if any of the modifiers are active. */
     XKB_STATE_MATCH_ANY = (1 << 0),
     /** Returns true if all of the modifiers are active. */
     XKB_STATE_MATCH_ALL = (1 << 1),
     /** Makes matching non-exclusive, i.e. will not return false if a
      *  modifier not specified in the arguments is active. */
     XKB_STATE_MATCH_NON_EXCLUSIVE = (1 << 16)
 };
 
 /**
  * The counterpart to xkb_state_update_mask for modifiers, to be used on
  * the server side of serialization.
  *
  * This entry point is intended for *server* applications; see @ref
  * server-client-state for details. *Client* applications should use the
  * xkb_state_mod_*_is_active API.
  *
  * @param state      The keyboard state.
  * @param 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.
  *
  * @memberof xkb_state
  */
 xkb_mod_mask_t
 xkb_state_serialize_mods(struct xkb_state *state,
                          enum xkb_state_component components);
 
 /**
  * The counterpart to xkb_state_update_mask for layouts, to be used on
  * the server side of serialization.
  *
  * This entry point is intended for *server* applications; see @ref
  * server-client-state for details. *Client* applications should use the
  * xkb_state_layout_*_is_active API.
  *
  * @param state      The keyboard state.
  * @param 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.
  *
  * @memberof xkb_state
  */
 xkb_layout_index_t
 xkb_state_serialize_layout(struct xkb_state *state,
                            enum xkb_state_component components);
 
 /**
  * Test whether a modifier is active in a given keyboard state by name.
  *
  * @returns 1 if the modifier is active, 0 if it is not.  If the modifier
  * name does not exist in the keymap, returns -1.
  *
  * @memberof xkb_state
  */
 int
 xkb_state_mod_name_is_active(struct xkb_state *state, const char *name,
                              enum xkb_state_component type);
 
 /**
  * Test whether a set of modifiers are active in a given keyboard state by
  * name.
  *
  * @param state The keyboard state.
  * @param type  The component of the state against which to match the
  * given modifiers.
  * @param match The manner by which to match the state against the
  * given modifiers.
  * @param ...   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.
  *
  * @memberof xkb_state
  */
 int
 xkb_state_mod_names_are_active(struct xkb_state *state,
                                enum xkb_state_component type,
                                enum xkb_state_match match,
                                ...);
 
 /**
  * Test whether a modifier is active in a given keyboard state by index.
  *
  * @returns 1 if the modifier is active, 0 if it is not.  If the modifier
  * index is invalid in the keymap, returns -1.
  *
  * @memberof xkb_state
  */
 int
 xkb_state_mod_index_is_active(struct xkb_state *state, xkb_mod_index_t idx,
                               enum xkb_state_component type);
 
 /**
  * Test whether a set of modifiers are active in a given keyboard state by
  * index.
  *
  * @param state The keyboard state.
  * @param type  The component of the state against which to match the
  * given modifiers.
  * @param match The manner by which to match the state against the
  * given modifiers.
  * @param ...   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.
  *
  * @memberof xkb_state
  */
 int
 xkb_state_mod_indices_are_active(struct xkb_state *state,
                                  enum xkb_state_component type,
                                  enum xkb_state_match match,
                                  ...);
 
 /**
  * @page consumed-modifiers Consumed Modifiers
  * @parblock
  *
  * Some functions, like 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:
  * @code
  *   (keysym == shortcut_keysym) &&
  *   ((state_mods & ~consumed_mods & significant_mods) == shortcut_mods)
  * @endcode
  *
  * @c state_mods are the modifiers reported by
  * xkb_state_mod_index_is_active() and similar functions.
  * @c consumed_mods are the modifiers reported by
  * xkb_state_mod_index_is_consumed() and similar functions.
  * @c significant_mods are decided upon by the application/toolkit/user;
  * it is up to them to decide whether these are configurable or hard-coded.
  *
  * @endparblock
  */
 
 /**
  * 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.
  */
 enum xkb_consumed_mode {
     /**
      * 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_XKB,
     /**
      * 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 @ref 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.
      */
     XKB_CONSUMED_MODE_GTK
 };
 
 /**
  * Get the mask of modifiers consumed by translating a given key.
  *
  * @param state The keyboard state.
  * @param key   The keycode of the key.
  * @param mode  The consumed modifiers mode to use; see enum description.
  *
  * @returns a mask of the consumed modifiers.
  *
  * @memberof xkb_state
  * @since 0.7.0
  */
 xkb_mod_mask_t
 xkb_state_key_get_consumed_mods2(struct xkb_state *state, xkb_keycode_t key,
                                  enum xkb_consumed_mode mode);
 
 /**
  * Same as xkb_state_key_get_consumed_mods2() with mode XKB_CONSUMED_MODE_XKB.
  *
  * @memberof xkb_state
  * @since 0.4.1
  */
 xkb_mod_mask_t
 xkb_state_key_get_consumed_mods(struct xkb_state *state, xkb_keycode_t key);
 
 /**
  * Test whether a modifier is consumed by keyboard state translation for
  * a key.
  *
  * @param state The keyboard state.
  * @param key   The keycode of the key.
  * @param idx   The index of the modifier to check.
  * @param 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.
  *
  * @sa xkb_state_mod_mask_remove_consumed()
  * @sa xkb_state_key_get_consumed_mods()
  * @memberof xkb_state
  * @since 0.7.0
  */
 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);
 
 /**
  * Same as xkb_state_mod_index_is_consumed2() with mode XKB_CONSUMED_MOD_XKB.
  *
  * @memberof xkb_state
  * @since 0.4.1
  */
 int
 xkb_state_mod_index_is_consumed(struct xkb_state *state, xkb_keycode_t key,
                                 xkb_mod_index_t idx);
 
 /**
  * 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()).
  *
  * @sa xkb_state_mod_index_is_consumed()
  * @memberof xkb_state
  */
 xkb_mod_mask_t
 xkb_state_mod_mask_remove_consumed(struct xkb_state *state, xkb_keycode_t key,
                                    xkb_mod_mask_t mask);
 
 /**
  * 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.
  *
  * @sa xkb_layout_index_t
  * @memberof xkb_state
  */
 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 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.
  *
  * @sa xkb_layout_index_t
  * @memberof xkb_state
  */
 int
 xkb_state_layout_index_is_active(struct xkb_state *state,
                                  xkb_layout_index_t idx,
                                  enum xkb_state_component type);
 
 /**
  * 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.
  *
  * @sa xkb_led_index_t
  * @memberof xkb_state
  */
 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 index.
  *
  * @returns 1 if the LED is active, 0 if it not.  If the LED index is not
  * valid in the keymap, returns -1.
  *
  * @sa xkb_led_index_t
  * @memberof xkb_state
  */
 int
 xkb_state_led_index_is_active(struct xkb_state *state, xkb_led_index_t idx);
 
 /** @} */
 
 /* Leave this include last, so it can pick up our types, etc. */
 #include <xkbcommon/xkbcommon-compat.h>
 
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
 
 #endif /* _XKBCOMMON_H_ */

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