path: root/src/state.c

/************************************************************
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
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used in advertising or publicity pertaining to distribution
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without any express or implied warranty.

SILICON GRAPHICS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
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DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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/*
 * Copyright © 2012 Intel Corporation
 *
 * 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>
 */

/*
 * This is a bastardised version of xkbActions.c from the X server which
 * does not support, for the moment:
 *   - AccessX sticky/debounce/etc (will come later)
 *   - pointer keys (may come later)
 *   - key redirects (unlikely)
 *   - messages (very unlikely)
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <assert.h>

#include "xkbcommon/xkbcommon.h"
#include "XKBcommonint.h"

struct xkb_filter {
    struct xkb_state *state;
    union xkb_action action;
    xkb_keycode_t keycode;
    uint32_t priv;
    int (*func)(struct xkb_filter *filter, xkb_keycode_t key, int down);
    int refcnt;
    struct xkb_filter *next;
};

static union xkb_action *
xkb_key_get_action(struct xkb_state *state, xkb_keycode_t key)
{
    int group, level;

    if (!XkbKeyHasActions(state->xkb, key) ||
        !XkbKeycodeInRange(state->xkb, key)) {
        static union xkb_action fake;
        memset(&fake, 0, sizeof(fake));
        fake.type = XkbSA_NoAction;
        return &fake;
    }

    group = xkb_key_get_group(state, key);
    level = xkb_key_get_level(state, key, group);

    return XkbKeyActionEntry(state->xkb, key, level, group);
}

static struct xkb_filter *
xkb_filter_new(struct xkb_state *state)
{
    int i;
    int old_size = state->num_filters;
    struct xkb_filter *filters = state->filters;

    for (i = 0; i < state->num_filters; i++) {
        if (filters[i].func)
            continue;
        filters[i].state = state;
        filters[i].refcnt = 1;
        return &filters[i];
    }

    if (state->num_filters > 0)
        state->num_filters *= 2;
    else
        state->num_filters = 4;
    filters = realloc(filters, state->num_filters * sizeof(*filters));
    if (!filters) { /* WSGO */
        state->num_filters = old_size;
        return NULL;
    }
    state->filters = filters;
    memset(&filters[old_size], 0,
           (state->num_filters - old_size) * sizeof(*filters));

    filters[old_size].state = state;
    filters[old_size].refcnt = 1;

    return &filters[old_size];
}

/***====================================================================***/

static int
xkb_filter_group_set_func(struct xkb_filter *filter, xkb_keycode_t keycode,
                          int down)
{
    if (keycode != filter->keycode) {
        filter->action.group.flags &= ~XkbSA_ClearLocks;
        return 1;
    }

    if (down) {
        filter->refcnt++;
        return 0;
    }
    else if (--filter->refcnt > 0) {
        return 0;
    }

    if (filter->action.group.flags & XkbSA_GroupAbsolute)
        filter->state->base_group = filter->action.group.group;
    else
        filter->state->base_group = -filter->action.group.group;
    if (filter->action.group.flags & XkbSA_ClearLocks)
        filter->state->locked_group = 0;

    filter->func = NULL;

    return 1;
}

static int
xkb_filter_group_set_new(struct xkb_state *state, xkb_keycode_t keycode,
                         union xkb_action *action)
{
    struct xkb_filter *filter = xkb_filter_new(state);

    if (!filter) /* WSGO */
        return -1;
    filter->keycode = keycode;
    filter->func = xkb_filter_group_set_func;
    filter->action = *action;

    if (action->group.flags & XkbSA_GroupAbsolute) {
        filter->action.group.group = filter->state->base_group;
        filter->state->base_group = action->group.group;
    }
    else {
        filter->state->base_group += action->group.group;
    }

    return 1;
}

static int
xkb_filter_mod_set_func(struct xkb_filter *filter, xkb_keycode_t keycode,
                        int down)
{
    if (keycode != filter->keycode) {
        filter->action.mods.flags &= ~XkbSA_ClearLocks;
        return 1;
    }

    if (down) {
        filter->refcnt++;
        return 0;
    }
    else if (--filter->refcnt > 0) {
        return 0;
    }

    filter->state->base_mods &= ~(filter->action.mods.mask);
    if (filter->action.mods.flags & XkbSA_ClearLocks)
        filter->state->locked_mods &= ~filter->action.mods.mask;

    filter->func = NULL;

    return 1;
}

static int
xkb_filter_mod_set_new(struct xkb_state *state, xkb_keycode_t keycode,
                       union xkb_action *action)
{
    struct xkb_filter *filter = xkb_filter_new(state);

    if (!filter) /* WSGO */
        return -1;
    filter->keycode = keycode;
    filter->func = xkb_filter_mod_set_func;
    filter->action = *action;

    filter->state->base_mods |= action->mods.mask;

    return 1;
}

static int
xkb_filter_mod_lock_func(struct xkb_filter *filter, xkb_keycode_t keycode,
                         int down)
{
    if (keycode != filter->keycode)
        return 1;

    if (down) {
        filter->refcnt++;
        return 0;
    }
    if (--filter->refcnt > 0)
        return 0;

    filter->state->locked_mods &= ~filter->priv;
    filter->func = NULL;
    return 1;
}

static int
xkb_filter_mod_lock_new(struct xkb_state *state, xkb_keycode_t keycode,
                        union xkb_action *action)
{
    struct xkb_filter *filter = xkb_filter_new(state);

    if (!filter) /* WSGO */
        return 0;

    filter->keycode = keycode;
    filter->func = xkb_filter_mod_lock_func;
    filter->action = *action;
    filter->priv = state->locked_mods & action->mods.mask;
    state->locked_mods |= action->mods.mask;

    return 1;
}

enum xkb_key_latch_state {
    NO_LATCH,
    LATCH_KEY_DOWN,
    LATCH_PENDING,
};

static int
xkb_filter_mod_latch_func(struct xkb_filter *filter, xkb_keycode_t keycode,
                          int down)
{
    enum xkb_key_latch_state latch = filter->priv;

    if (down && latch == LATCH_PENDING) {
        /* If this is a new keypress and we're awaiting our single latched
         * keypress, then either break the latch if any random key is pressed,
         * or promote it to a lock or plain base set if it's the same
         * modifier. */
        union xkb_action *action = xkb_key_get_action(filter->state, keycode);
        if (action->type == XkbSA_LatchMods &&
            action->mods.flags == filter->action.mods.flags &&
            action->mods.mask == filter->action.mods.mask) {
            filter->action = *action;
            if (filter->action.mods.flags & XkbSA_LatchToLock) {
                filter->action.type = XkbSA_LockMods;
                filter->func = xkb_filter_mod_lock_func;
                filter->state->locked_mods |= filter->action.mods.mask;
            }
            else {
                filter->action.type = XkbSA_SetMods;
                filter->func = xkb_filter_mod_set_func;
                filter->state->base_mods |= filter->action.mods.mask;
            }
            filter->keycode = keycode;
            filter->state->latched_mods &= ~filter->action.mods.mask;
            /* XXX beep beep! */
            return 0;
        }
        else if (((1 << action->type) & XkbSA_BreakLatch)) {
            /* XXX: This may be totally broken, we might need to break the
             *      latch in the next run after this press? */
            filter->state->latched_mods &= ~filter->action.mods.mask;
            filter->func = NULL;
            return 1;
        }
    }
    else if (!down && keycode == filter->keycode) {
        /* Our key got released.  If we've set it to clear locks, and we
         * currently have the same modifiers locked, then release them and
         * don't actually latch.  Else we've actually hit the latching
         * stage, so set PENDING and move our modifier from base to
         * latched. */
        if (latch == NO_LATCH ||
            ((filter->action.mods.flags & XkbSA_ClearLocks) &&
             (filter->state->locked_mods & filter->action.mods.mask) ==
             filter->action.mods.mask)) {
            /* XXX: We might be a bit overenthusiastic about clearing
             *      mods other filters have set here? */
            if (latch == LATCH_PENDING)
                filter->state->latched_mods &= ~filter->action.mods.mask;
            else
                filter->state->base_mods &= ~filter->action.mods.mask;
            filter->state->locked_mods &= ~filter->action.mods.mask;
            filter->func = NULL;
        }
        else {
            latch = LATCH_PENDING;
            filter->state->base_mods &= ~filter->action.mods.mask;
            filter->state->latched_mods |= filter->action.mods.mask;
            /* XXX beep beep! */
        }
    }
    else if (down && latch == LATCH_KEY_DOWN) {
        /* Someone's pressed another key while we've still got the latching
         * key held down, so keep the base modifier state active (from
         * xkb_filter_mod_latch_new), but don't trip the latch, just clear
         * it as soon as the modifier gets released. */
        latch = NO_LATCH;
    }

    filter->priv = latch;

    return 1;
}

static int
xkb_filter_mod_latch_new(struct xkb_state *state, xkb_keycode_t keycode,
                         union xkb_action *action)
{
    struct xkb_filter *filter = xkb_filter_new(state);
    enum xkb_key_latch_state latch = LATCH_KEY_DOWN;

    if (!filter) /* WSGO */
        return -1;
    filter->keycode = keycode;
    filter->priv = latch;
    filter->func = xkb_filter_mod_latch_func;
    filter->action = *action;

    filter->state->base_mods |= action->mods.mask;

    return 1;
}

/**
 * Applies any relevant filters to the key, first from the list of filters
 * that are currently active, then if no filter has claimed the key, possibly
 * apply a new filter from the key action.
 */
static void
xkb_filter_apply_all(struct xkb_state *state, xkb_keycode_t key, int down)
{
    struct xkb_filter *filters = state->filters;
    union xkb_action *act = NULL;
    int send = 1;
    int i;

    /* First run through all the currently active filters and see if any of
     * them have claimed this event. */
    for (i = 0; i < state->num_filters; i++) {
        if (!filters[i].func)
            continue;
        send &= (*filters[i].func)(&filters[i], key, down);
    }

    if (!send || !down)
        return;

    act = xkb_key_get_action(state, key);
    switch (act->type) {
    case XkbSA_SetMods:
        send = xkb_filter_mod_set_new(state, key, act);
        break;
    case XkbSA_LatchMods:
        send = xkb_filter_mod_latch_new(state, key, act);
        break;
    case XkbSA_LockMods:
        send = xkb_filter_mod_lock_new(state, key, act);
        break;
    case XkbSA_SetGroup:
        send = xkb_filter_group_set_new(state, key, act);
        break;
#if 0
    case XkbSA_LatchGroup:
        send = xkb_filter_mod_latch_new(state, key, act);
        break;
    case XkbSA_LockGroup:
        send = xkb_filter_group_lock_new(state, key, act);
        break;
#endif
    }

    return;
}

struct xkb_state *
xkb_state_new(struct xkb_desc *xkb)
{
    struct xkb_state *ret;

    if (!xkb)
        return NULL;

    ret = calloc(sizeof(*ret), 1);
    if (!ret)
        return NULL;

    ret->refcnt = 1;
    ret->xkb = xkb;
    xkb_map_ref(xkb);

    return ret;
}

void
xkb_state_unref(struct xkb_state *state)
{
    state->refcnt--;
    assert(state->refcnt >= 0);
    if (state->refcnt == 0)
        return;

    xkb_map_unref(state->xkb);
    free(state);
}

/**
 * Update the LED state to match the rest of the xkb_state.
 */
static void
xkb_state_led_update_all(struct xkb_state *state)
{
    xkb_led_index_t led;

    state->leds = 0;

    for (led = 0; led < XkbNumIndicators; led++) {
        struct xkb_indicator_map *map = &state->xkb->indicators->maps[led];
        uint32_t mod_mask = 0;
        uint32_t group_mask = 0;

        if (!map->which_mods && !map->which_groups && !map->ctrls)
            continue;

        if (map->which_mods) {
            if (map->which_mods & XkbIM_UseBase)
                mod_mask |= state->base_mods;
            if (map->which_mods & XkbIM_UseLatched)
                mod_mask |= state->latched_mods;
            if (map->which_mods & XkbIM_UseLocked)
                mod_mask |= state->locked_mods;
            if (map->which_mods & XkbIM_UseEffective)
                mod_mask |= state->mods;
            if ((map->mods.mask & mod_mask))
                state->leds |= (1 << led);
        }
        else if (map->which_groups) {
            if (map->which_mods & XkbIM_UseBase)
                group_mask |= (1 << state->base_group);
            if (map->which_mods & XkbIM_UseLatched)
                group_mask |= (1 << state->latched_group);
            if (map->which_mods & XkbIM_UseLocked)
                group_mask |= (1 << state->locked_group);
            if (map->which_mods & XkbIM_UseEffective)
                group_mask |= (1 << state->group);
            if ((map->groups & group_mask))
                state->leds |= (1 << led);
        }
        else if (map->ctrls) {
            if ((map->ctrls & state->xkb->ctrls->enabled_ctrls))
                state->leds |= (1 << led);
        }
    }
}

/**
 * Calculates the derived state (effective mods/group and LEDs) from an
 * up-to-date xkb_state.
 */
static void
xkb_state_update_derived(struct xkb_state *state)
{
    state->mods = (state->base_mods | state->latched_mods | state->locked_mods);
    /* FIXME: Clamp/wrap locked_group */
    state->group = state->locked_group + state->base_group +
                   state->latched_group;
    /* FIXME: Clamp/wrap effective group */

    xkb_state_led_update_all(state);
}

/**
 * Given a particular key event, updates the state structure to reflect the
 * new modifiers.
 */
void
xkb_state_update_key(struct xkb_state *state, xkb_keycode_t key, int down)
{
    xkb_filter_apply_all(state, key, down);
    xkb_state_update_derived(state);
}

/**
 * Updates the state from a set of explicit masks as gained from
 * xkb_state_serialise_mods and xkb_state_serialise_groups.  As noted in the
 * documentation for these functions in xkbcommon.h, this round-trip is
 * lossy, and should only be used to update a slave state mirroring the
 * master, e.g. in a client/server window system.
 */
void
xkb_state_update_mask(struct xkb_state *state,
                      xkb_mod_mask_t base_mods,
                      xkb_mod_mask_t latched_mods,
                      xkb_mod_mask_t locked_mods,
                      xkb_group_index_t base_group,
                      xkb_group_index_t latched_group,
                      xkb_group_index_t locked_group)
{
    xkb_mod_mask_t mod;

    state->base_mods = 0;
    state->latched_mods = 0;
    state->locked_mods = 0;
    for (mod = 0; mod < xkb_map_num_mods(state->xkb); mod++) {
        xkb_mod_mask_t idx = (1 << mod);
        if (base_mods & idx)
            state->base_mods |= idx;
        if (latched_mods & idx)
            state->latched_mods |= idx;
        if (locked_mods & idx)
            state->locked_mods |= idx;
    }

    state->base_group = base_group;
    state->latched_group = latched_group;
    state->locked_group = locked_group;

    xkb_state_update_derived(state);
}

/**
 * Serialises the requested modifier state into an xkb_mod_mask_t, with all
 * the same disclaimers as in xkb_state_update_mask.
 */
xkb_mod_mask_t
xkb_state_serialise_mods(struct xkb_state *state,
                         enum xkb_state_component type)
{
    xkb_mod_mask_t ret = 0;

    if (type == XKB_STATE_EFFECTIVE)
        return state->mods;

    if (type & XKB_STATE_DEPRESSED)
        ret |= state->base_mods;
    if (type & XKB_STATE_LATCHED)
        ret |= state->latched_mods;
    if (type & XKB_STATE_LOCKED)
        ret |= state->locked_mods;

    return ret;
}

/**
 * Serialises the requested group state, with all the same disclaimers as
 * in xkb_state_update_mask.
 */
xkb_group_index_t
xkb_state_serialise_group(struct xkb_state *state,
                          enum xkb_state_component type)
{
    xkb_group_index_t ret = 0;

    if (type == XKB_STATE_EFFECTIVE)
        return state->group;

    if (type & XKB_STATE_DEPRESSED)
        ret += state->base_group;
    if (type & XKB_STATE_LATCHED)
        ret += state->latched_group;
    if (type & XKB_STATE_LOCKED)
        ret += state->locked_group;

    return ret;
}

/**
 * Returns 1 if the given modifier is active with the specified type(s), 0 if
 * not, or -1 if the modifier is invalid.
 */
int
xkb_state_mod_index_is_active(struct xkb_state *state,
                              xkb_mod_index_t idx,
                              enum xkb_state_component type)
{
    int ret = 0;

    if (idx >= xkb_map_num_mods(state->xkb))
        return -1;

    if (type & XKB_STATE_DEPRESSED)
        ret |= (state->base_mods & (1 << idx));
    if (type & XKB_STATE_LATCHED)
        ret |= (state->latched_mods & (1 << idx));
    if (type & XKB_STATE_LOCKED)
        ret |= (state->locked_mods & (1 << idx));

    return ret;
}

/**
 * Returns 1 if the given modifier is active with the specified type(s), 0 if
 * not, or -1 if the modifier is invalid.
 */
int
xkb_state_mod_name_is_active(struct xkb_state *state, const char *name,
                             enum xkb_state_component type)
{
    xkb_mod_index_t idx = xkb_map_mod_get_index(state->xkb, name);

    if (idx == XKB_MOD_INVALID)
        return -1;

    return xkb_state_mod_index_is_active(state, idx, type);
}

/**
 * Returns 1 if the given group is active with the specified type(s), 0 if
 * not, or -1 if the group is invalid.
 */
int
xkb_state_group_index_is_active(struct xkb_state *state,
                                xkb_group_index_t idx,
                                enum xkb_state_component type)
{
    int ret = 0;

    if (idx >= xkb_map_num_groups(state->xkb))
        return -1;

    if (type & XKB_STATE_DEPRESSED)
        ret |= (state->base_group == idx);
    if (type & XKB_STATE_LATCHED)
        ret |= (state->latched_group == idx);
    if (type & XKB_STATE_LOCKED)
        ret |= (state->locked_group == idx);

    return ret;
}

/**
 * Returns 1 if the given modifier is active with the specified type(s), 0 if
 * not, or -1 if the modifier is invalid.
 */
int
xkb_state_group_name_is_active(struct xkb_state *state, const char *name,
                               enum xkb_state_component type)
{
    xkb_group_index_t idx = xkb_map_group_get_index(state->xkb, name);

    if (idx == XKB_GROUP_INVALID)
        return -1;

    return xkb_state_group_index_is_active(state, idx, type);
}

/**
 * Returns 1 if the given LED is active, 0 if not, or -1 if the LED is invalid.
 */
int
xkb_state_led_index_is_active(struct xkb_state *state, xkb_led_index_t idx)
{
    if (idx >= xkb_map_num_leds(state->xkb))
        return -1;

    return !!(state->leds & (1 << idx));
}

/**
 * Returns 1 if the given LED is active, 0 if not, or -1 if the LED is invalid.
 */
int
xkb_state_led_name_is_active(struct xkb_state *state, const char *name)
{
    xkb_led_index_t idx = xkb_map_led_get_index(state->xkb, name);

    if (idx == XKB_LED_INVALID)
        return -1;

    return xkb_state_led_index_is_active(state, idx);
}