qmk_firmware

QMK firmware for my keyboards (Corne, Sweep Ferris) and trackball (Ploopy Adept)
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action_tapping.c (43776B)


      1 #include <stdint.h>
      2 #include <stdbool.h>
      3 
      4 #include "action.h"
      5 #include "action_layer.h"
      6 #include "action_tapping.h"
      7 #include "action_util.h"
      8 #include "keycode.h"
      9 #include "keycode_config.h"
     10 #include "quantum_keycodes.h"
     11 #include "timer.h"
     12 #include "wait.h"
     13 
     14 #ifndef NO_ACTION_TAPPING
     15 
     16 #    if defined(IGNORE_MOD_TAP_INTERRUPT_PER_KEY)
     17 #        error "IGNORE_MOD_TAP_INTERRUPT_PER_KEY has been removed; the code needs to be ported to use HOLD_ON_OTHER_KEY_PRESS_PER_KEY instead."
     18 #    elif defined(IGNORE_MOD_TAP_INTERRUPT)
     19 #        error "IGNORE_MOD_TAP_INTERRUPT is no longer necessary as it is now the default behavior of mod-tap keys. Please remove it from your config."
     20 #    endif
     21 
     22 #    ifndef COMBO_ENABLE
     23 #        define IS_TAPPING_RECORD(r) (KEYEQ(tapping_key.event.key, (r->event.key)))
     24 #    else
     25 #        define IS_TAPPING_RECORD(r) (KEYEQ(tapping_key.event.key, (r->event.key)) && tapping_key.keycode == r->keycode)
     26 #    endif
     27 #    define WITHIN_TAPPING_TERM(e) (TIMER_DIFF_16(e.time, tapping_key.event.time) < GET_TAPPING_TERM(get_record_keycode(&tapping_key, false), &tapping_key))
     28 #    define WITHIN_QUICK_TAP_TERM(e) (TIMER_DIFF_16(e.time, tapping_key.event.time) < GET_QUICK_TAP_TERM(get_record_keycode(&tapping_key, false), &tapping_key))
     29 
     30 #    ifdef DYNAMIC_TAPPING_TERM_ENABLE
     31 uint16_t g_tapping_term = TAPPING_TERM;
     32 #    endif
     33 
     34 #    ifdef TAPPING_TERM_PER_KEY
     35 __attribute__((weak)) uint16_t get_tapping_term(uint16_t keycode, keyrecord_t *record) {
     36 #        ifdef DYNAMIC_TAPPING_TERM_ENABLE
     37     return g_tapping_term;
     38 #        else
     39     return TAPPING_TERM;
     40 #        endif
     41 }
     42 #    endif
     43 
     44 #    ifdef QUICK_TAP_TERM_PER_KEY
     45 __attribute__((weak)) uint16_t get_quick_tap_term(uint16_t keycode, keyrecord_t *record) {
     46     return QUICK_TAP_TERM;
     47 }
     48 #    endif
     49 
     50 #    ifdef PERMISSIVE_HOLD_PER_KEY
     51 __attribute__((weak)) bool get_permissive_hold(uint16_t keycode, keyrecord_t *record) {
     52     return false;
     53 }
     54 #    endif
     55 
     56 #    ifdef SPECULATIVE_HOLD
     57 typedef struct {
     58     keypos_t key;
     59     uint8_t  mods;
     60 } speculative_key_t;
     61 #        define SPECULATIVE_KEYS_SIZE 8
     62 static speculative_key_t speculative_keys[SPECULATIVE_KEYS_SIZE] = {};
     63 static uint8_t           num_speculative_keys                    = 0;
     64 static uint8_t           prev_speculative_mods                   = 0;
     65 static uint8_t           speculative_mods                        = 0;
     66 
     67 /** Handler to be called on incoming press events. */
     68 static void speculative_key_press(keyrecord_t *record);
     69 #    endif // SPECULATIVE_HOLD
     70 
     71 #    if defined(CHORDAL_HOLD) || defined(FLOW_TAP_TERM)
     72 #        define REGISTERED_TAPS_SIZE 8
     73 // Array of tap-hold keys that have been settled as tapped but not yet released.
     74 static keypos_t registered_taps[REGISTERED_TAPS_SIZE] = {};
     75 static uint8_t  num_registered_taps                   = 0;
     76 
     77 /** Adds `key` to the registered_taps array. */
     78 static void registered_taps_add(keypos_t key);
     79 /** Returns the index of `key` in registered_taps, or -1 if not found. */
     80 static int8_t registered_tap_find(keypos_t key);
     81 /** Removes index `i` from the registered_taps array. */
     82 static void registered_taps_del_index(uint8_t i);
     83 /** Logs the registered_taps array for debugging. */
     84 static void debug_registered_taps(void);
     85 
     86 static bool is_mt_or_lt(uint16_t keycode) {
     87     return IS_QK_MOD_TAP(keycode) || IS_QK_LAYER_TAP(keycode);
     88 }
     89 #    endif // defined(CHORDAL_HOLD) || defined(FLOW_TAP_TERM)
     90 
     91 #    if defined(CHORDAL_HOLD)
     92 extern const char chordal_hold_layout[MATRIX_ROWS][MATRIX_COLS] PROGMEM;
     93 
     94 /** \brief Finds which queued events should be held according to Chordal Hold.
     95  *
     96  * In a situation with multiple unsettled tap-hold key presses, scan the queue
     97  * up until the first release, non-tap-hold, or one-shot event and find the
     98  * latest event in the queue that settles as held according to
     99  * get_chordal_hold().
    100  *
    101  * \return Index of the first tap, or equivalently, one past the latest hold.
    102  */
    103 static uint8_t waiting_buffer_find_chordal_hold_tap(void);
    104 
    105 /** Processes queued events up to and including `key` as tapped. */
    106 static void waiting_buffer_chordal_hold_taps_until(keypos_t key);
    107 
    108 /** \brief Processes and pops buffered events until the first tap-hold event. */
    109 static void waiting_buffer_process_regular(void);
    110 #    endif // CHORDAL_HOLD
    111 
    112 #    ifdef HOLD_ON_OTHER_KEY_PRESS_PER_KEY
    113 __attribute__((weak)) bool get_hold_on_other_key_press(uint16_t keycode, keyrecord_t *record) {
    114     return false;
    115 }
    116 #    endif
    117 
    118 #    if defined(AUTO_SHIFT_ENABLE) && defined(RETRO_SHIFT)
    119 #        include "process_auto_shift.h"
    120 #    endif
    121 
    122 #    if defined(FLOW_TAP_TERM)
    123 static uint16_t flow_tap_prev_keycode = KC_NO;
    124 static uint16_t flow_tap_prev_time    = 0;
    125 static bool     flow_tap_expired      = true;
    126 
    127 static bool flow_tap_key_if_within_term(keyrecord_t *record, uint16_t prev_time);
    128 #    endif // defined(FLOW_TAP_TERM)
    129 
    130 static keyrecord_t tapping_key                         = {};
    131 static keyrecord_t waiting_buffer[WAITING_BUFFER_SIZE] = {};
    132 static uint8_t     waiting_buffer_head                 = 0;
    133 static uint8_t     waiting_buffer_tail                 = 0;
    134 
    135 static bool process_tapping(keyrecord_t *record);
    136 static bool waiting_buffer_enq(keyrecord_t record);
    137 static void waiting_buffer_clear(void);
    138 static bool waiting_buffer_typed(keyevent_t event);
    139 static bool waiting_buffer_has_anykey_pressed(void);
    140 static void waiting_buffer_scan_tap(void);
    141 static void debug_tapping_key(void);
    142 static void debug_waiting_buffer(void);
    143 
    144 /** \brief Action Tapping Process
    145  *
    146  * FIXME: Needs doc
    147  */
    148 void action_tapping_process(keyrecord_t record) {
    149 #    ifdef SPECULATIVE_HOLD
    150     prev_speculative_mods = speculative_mods;
    151     if (record.event.pressed) {
    152         speculative_key_press(&record);
    153     }
    154 #    endif // SPECULATIVE_HOLD
    155 
    156     if (process_tapping(&record)) {
    157         if (IS_EVENT(record.event)) {
    158             ac_dprintf("processed: ");
    159             debug_record(record);
    160             ac_dprintf("\n");
    161         }
    162     } else {
    163         if (!waiting_buffer_enq(record)) {
    164             // clear all in case of overflow.
    165             ac_dprintf("OVERFLOW: CLEAR ALL STATES\n");
    166             clear_keyboard();
    167             waiting_buffer_clear();
    168             tapping_key = (keyrecord_t){0};
    169         }
    170     }
    171 
    172 #    ifdef SPECULATIVE_HOLD
    173     if (speculative_mods != prev_speculative_mods) {
    174         send_keyboard_report();
    175     }
    176 #    endif // SPECULATIVE_HOLD
    177 
    178     // process waiting_buffer
    179     if (IS_EVENT(record.event) && waiting_buffer_head != waiting_buffer_tail) {
    180         ac_dprintf("---- action_exec: process waiting_buffer -----\n");
    181     }
    182     for (; waiting_buffer_tail != waiting_buffer_head; waiting_buffer_tail = (waiting_buffer_tail + 1) % WAITING_BUFFER_SIZE) {
    183         if (process_tapping(&waiting_buffer[waiting_buffer_tail])) {
    184             ac_dprintf("processed: waiting_buffer[%u] =", waiting_buffer_tail);
    185             debug_record(waiting_buffer[waiting_buffer_tail]);
    186             ac_dprintf("\n\n");
    187         } else {
    188             break;
    189         }
    190     }
    191     if (IS_EVENT(record.event)) {
    192         ac_dprintf("\n");
    193     } else {
    194 #    ifdef FLOW_TAP_TERM
    195         if (!flow_tap_expired && TIMER_DIFF_16(record.event.time, flow_tap_prev_time) >= INT16_MAX / 2) {
    196             flow_tap_expired = true;
    197         }
    198 #    endif // FLOW_TAP_TERM
    199     }
    200 }
    201 
    202 /* Some conditionally defined helper macros to keep process_tapping more
    203  * readable. The conditional definition of tapping_keycode and all the
    204  * conditional uses of it are hidden inside macros named TAP_...
    205  */
    206 #    define TAP_DEFINE_KEYCODE const uint16_t tapping_keycode = get_record_keycode(&tapping_key, false)
    207 
    208 #    if defined(AUTO_SHIFT_ENABLE) && defined(RETRO_SHIFT)
    209 #        ifdef RETRO_TAPPING_PER_KEY
    210 #            define TAP_GET_RETRO_TAPPING(keyp) get_auto_shifted_key(tapping_keycode, keyp) && get_retro_tapping(tapping_keycode, &tapping_key)
    211 #        else
    212 #            define TAP_GET_RETRO_TAPPING(keyp) get_auto_shifted_key(tapping_keycode, keyp)
    213 #        endif
    214 /* Used to extend TAPPING_TERM:
    215  *     indefinitely if RETRO_SHIFT does not have a value
    216  *     to RETRO_SHIFT if RETRO_SHIFT is set
    217  * for possibly retro shifted keys.
    218  */
    219 #        define MAYBE_RETRO_SHIFTING(ev, keyp) (get_auto_shifted_key(tapping_keycode, keyp) && TAP_GET_RETRO_TAPPING(keyp) && ((RETRO_SHIFT + 0) == 0 || TIMER_DIFF_16((ev).time, tapping_key.event.time) < (RETRO_SHIFT + 0)))
    220 #        define TAP_IS_LT IS_QK_LAYER_TAP(tapping_keycode)
    221 #        define TAP_IS_MT IS_QK_MOD_TAP(tapping_keycode)
    222 #        define TAP_IS_RETRO IS_RETRO(tapping_keycode)
    223 #    else
    224 #        define TAP_GET_RETRO_TAPPING(keyp) false
    225 #        define MAYBE_RETRO_SHIFTING(ev, kp) false
    226 #        define TAP_IS_LT false
    227 #        define TAP_IS_MT false
    228 #        define TAP_IS_RETRO false
    229 #    endif
    230 
    231 #    ifdef PERMISSIVE_HOLD_PER_KEY
    232 #        define TAP_GET_PERMISSIVE_HOLD get_permissive_hold(tapping_keycode, &tapping_key)
    233 #    elif defined(PERMISSIVE_HOLD)
    234 #        define TAP_GET_PERMISSIVE_HOLD true
    235 #    else
    236 #        define TAP_GET_PERMISSIVE_HOLD false
    237 #    endif
    238 
    239 #    ifdef HOLD_ON_OTHER_KEY_PRESS_PER_KEY
    240 #        define TAP_GET_HOLD_ON_OTHER_KEY_PRESS get_hold_on_other_key_press(tapping_keycode, &tapping_key)
    241 #    elif defined(HOLD_ON_OTHER_KEY_PRESS)
    242 #        define TAP_GET_HOLD_ON_OTHER_KEY_PRESS true
    243 #    else
    244 #        define TAP_GET_HOLD_ON_OTHER_KEY_PRESS false
    245 #    endif
    246 
    247 /** \brief Tapping
    248  *
    249  * Rule: Tap key is typed(pressed and released) within TAPPING_TERM.
    250  *       (without interfering by typing other key)
    251  */
    252 /* return true when key event is processed or consumed. */
    253 bool process_tapping(keyrecord_t *keyp) {
    254     const keyevent_t event = keyp->event;
    255 
    256 #    if defined(CHORDAL_HOLD) || defined(FLOW_TAP_TERM)
    257     if (!event.pressed) {
    258         const int8_t i = registered_tap_find(event.key);
    259         if (i != -1) {
    260             // If a tap-hold key was previously settled as tapped, set its
    261             // tap.count correspondingly on release.
    262             keyp->tap.count = 1;
    263             registered_taps_del_index(i);
    264             ac_dprintf("Found tap release for [%d]\n", i);
    265             debug_registered_taps();
    266         }
    267     }
    268 #    endif // defined(CHORDAL_HOLD) || defined(FLOW_TAP_TERM)
    269 
    270     // state machine is in the "reset" state, no tapping key is to be
    271     // processed
    272     if (IS_NOEVENT(tapping_key.event)) {
    273         if (!IS_EVENT(event)) {
    274             // early return for tick events
    275         } else if (event.pressed && is_tap_record(keyp)) {
    276             // the currently pressed key is a tapping key, therefore transition
    277             // into the "pressed" tapping key state
    278 
    279 #    if defined(FLOW_TAP_TERM)
    280             if (flow_tap_key_if_within_term(keyp, flow_tap_prev_time)) {
    281                 return true;
    282             }
    283 #    endif // defined(FLOW_TAP_TERM)
    284 
    285             ac_dprintf("Tapping: Start(Press tap key).\n");
    286             tapping_key = *keyp;
    287             process_record_tap_hint(&tapping_key);
    288             waiting_buffer_scan_tap();
    289             debug_tapping_key();
    290         } else {
    291             // the current key is just a regular key, pass it on for regular
    292             // processing
    293             process_record(keyp);
    294         }
    295 
    296         return true;
    297     }
    298 
    299 #    if (defined(AUTO_SHIFT_ENABLE) && defined(RETRO_SHIFT)) || defined(PERMISSIVE_HOLD_PER_KEY) || defined(CHORDAL_HOLD) || defined(HOLD_ON_OTHER_KEY_PRESS_PER_KEY)
    300     TAP_DEFINE_KEYCODE;
    301 #    endif
    302 
    303     // process "pressed" tapping key state
    304     if (tapping_key.event.pressed) {
    305         if (WITHIN_TAPPING_TERM(event) || MAYBE_RETRO_SHIFTING(event, keyp)) {
    306             if (IS_NOEVENT(event)) {
    307                 // early return for tick events
    308                 return true;
    309             }
    310 
    311             if (tapping_key.tap.count == 0) {
    312                 if (IS_TAPPING_RECORD(keyp) && !event.pressed) {
    313                     // first tap!
    314                     ac_dprintf("Tapping: First tap(0->1).\n");
    315                     tapping_key.tap.count = 1;
    316                     debug_tapping_key();
    317                     process_record(&tapping_key);
    318 
    319                     // copy tapping state
    320                     keyp->tap = tapping_key.tap;
    321 
    322 #    if defined(FLOW_TAP_TERM)
    323                     // Now that tapping_key has settled as tapped, check whether
    324                     // Flow Tap applies to following yet-unsettled keys.
    325                     uint16_t prev_time = tapping_key.event.time;
    326                     for (; waiting_buffer_tail != waiting_buffer_head; waiting_buffer_tail = (waiting_buffer_tail + 1) % WAITING_BUFFER_SIZE) {
    327                         keyrecord_t *record = &waiting_buffer[waiting_buffer_tail];
    328                         if (!record->event.pressed) {
    329                             break;
    330                         }
    331                         const int16_t next_time = record->event.time;
    332                         if (!is_tap_record(record)) {
    333                             process_record(record);
    334                         } else if (!flow_tap_key_if_within_term(record, prev_time)) {
    335                             break;
    336                         }
    337                         prev_time = next_time;
    338                     }
    339                     debug_waiting_buffer();
    340 #    endif // defined(FLOW_TAP_TERM)
    341 
    342                     // enqueue
    343                     return false;
    344                 }
    345 #    if defined(CHORDAL_HOLD)
    346                 else if (is_mt_or_lt(tapping_keycode) && !event.pressed && waiting_buffer_typed(event) && !get_chordal_hold(tapping_keycode, &tapping_key, get_record_keycode(keyp, false), keyp)) {
    347                     // Key release that is not a chord with the tapping key.
    348                     // Settle the tapping key and any other pending tap-hold
    349                     // keys preceding the press of this key as tapped.
    350 
    351                     ac_dprintf("Tapping: End. Chord considered a tap\n");
    352                     tapping_key.tap.count = 1;
    353                     registered_taps_add(tapping_key.event.key);
    354                     process_record(&tapping_key);
    355                     tapping_key = (keyrecord_t){0};
    356 
    357                     waiting_buffer_chordal_hold_taps_until(event.key);
    358                     debug_registered_taps();
    359                     debug_waiting_buffer();
    360                     // enqueue
    361                     return false;
    362                 }
    363 #    endif      // CHORDAL_HOLD
    364                 /* Process a key typed within TAPPING_TERM
    365                  * This can register the key before settlement of tapping,
    366                  * useful for long TAPPING_TERM but may prevent fast typing.
    367                  */
    368                 // clang-format off
    369                 else if (
    370                     !event.pressed && waiting_buffer_typed(event) &&
    371                     (
    372                         TAP_GET_PERMISSIVE_HOLD ||
    373                         // Causes nested taps to not wait past TAPPING_TERM/RETRO_SHIFT
    374                         // unnecessarily and fixes them for Layer Taps.
    375                         TAP_GET_RETRO_TAPPING(keyp)
    376                     )
    377                 ) {
    378                     // clang-format on
    379                     ac_dprintf("Tapping: End. No tap. Interfered by typing key\n");
    380                     process_record(&tapping_key);
    381 
    382 #    if defined(CHORDAL_HOLD)
    383                     uint8_t first_tap = waiting_buffer_find_chordal_hold_tap();
    384                     ac_dprintf("first_tap = %u\n", first_tap);
    385                     if (first_tap < WAITING_BUFFER_SIZE) {
    386                         for (; waiting_buffer_tail != first_tap; waiting_buffer_tail = (waiting_buffer_tail + 1) % WAITING_BUFFER_SIZE) {
    387                             ac_dprintf("Processing [%u]\n", waiting_buffer_tail);
    388                             process_record(&waiting_buffer[waiting_buffer_tail]);
    389                         }
    390                     }
    391 
    392                     waiting_buffer_chordal_hold_taps_until(event.key);
    393                     debug_registered_taps();
    394                     debug_waiting_buffer();
    395 #    endif // CHORDAL_HOLD
    396 
    397                     tapping_key = (keyrecord_t){0};
    398                     debug_tapping_key();
    399                     // enqueue
    400                     return false;
    401                 }
    402                 /* Process release event of a key pressed before tapping starts
    403                  * Without this unexpected repeating will occur with having fast repeating setting
    404                  * https://github.com/tmk/tmk_keyboard/issues/60
    405                  *
    406                  * NOTE: This workaround causes events to process out of order,
    407                  * e.g. in a rolled press of three tap-hold keys like
    408                  *
    409                  *   "A down, B down, C down, A up, B up, C up"
    410                  *
    411                  * events are processed as
    412                  *
    413                  *   "A down, B down, A up, B up, C down, C up"
    414                  *
    415                  * It seems incorrect to process keyp before the tapping key.
    416                  * This workaround is old, from 2013. This might no longer
    417                  * be needed for the original problem it was meant to address.
    418                  */
    419                 else if (!event.pressed && !waiting_buffer_typed(event)) {
    420                     // Modifier/Layer should be retained till end of this tapping.
    421                     action_t action = layer_switch_get_action(event.key);
    422                     switch (action.kind.id) {
    423                         case ACT_LMODS:
    424                         case ACT_RMODS:
    425                             if (action.key.mods && !action.key.code) return false;
    426                             if (IS_MODIFIER_KEYCODE(action.key.code)) return false;
    427                             break;
    428                         case ACT_LMODS_TAP:
    429                         case ACT_RMODS_TAP:
    430                             if (action.key.mods && keyp->tap.count == 0) return false;
    431                             if (IS_MODIFIER_KEYCODE(action.key.code)) return false;
    432                             break;
    433                         case ACT_LAYER_TAP:
    434                         case ACT_LAYER_TAP_EXT:
    435                             switch (action.layer_tap.code) {
    436                                 case 0 ...(OP_TAP_TOGGLE - 1):
    437                                 case OP_ON_OFF:
    438                                 case OP_OFF_ON:
    439                                 case OP_SET_CLEAR:
    440                                     return false;
    441                             }
    442                             break;
    443                     }
    444                     // Release of key should be process immediately.
    445                     ac_dprintf("Tapping: release event of a key pressed before tapping\n");
    446                     process_record(keyp);
    447                     return true;
    448                 } else {
    449                     // set interrupted flag when other key pressed during tapping
    450                     if (event.pressed) {
    451                         tapping_key.tap.interrupted = true;
    452 
    453 #    if defined(CHORDAL_HOLD)
    454                         if (is_mt_or_lt(tapping_keycode) && !get_chordal_hold(tapping_keycode, &tapping_key, get_record_keycode(keyp, false), keyp)) {
    455                             // In process_action(), HOLD_ON_OTHER_KEY_PRESS
    456                             // will revert interrupted events to holds, so
    457                             // this needs to be set false.
    458                             tapping_key.tap.interrupted = false;
    459 
    460                             if (!is_tap_record(keyp)) {
    461                                 ac_dprintf("Tapping: End. Chord considered a tap\n");
    462                                 tapping_key.tap.count = 1;
    463                                 registered_taps_add(tapping_key.event.key);
    464                                 debug_registered_taps();
    465                                 process_record(&tapping_key);
    466                                 tapping_key = (keyrecord_t){0};
    467                             }
    468                         } else
    469 #    endif // CHORDAL_HOLD
    470                             if (TAP_GET_HOLD_ON_OTHER_KEY_PRESS
    471 #    if defined(AUTO_SHIFT_ENABLE) && defined(RETRO_SHIFT)
    472                                 // Auto Shift cannot evaluate this early
    473                                 // Retro Shift uses the hold action for all nested taps even without HOLD_ON_OTHER_KEY_PRESS, so this is fine to skip
    474                                 && !(MAYBE_RETRO_SHIFTING(event, keyp) && get_auto_shifted_key(get_record_keycode(keyp, false), keyp))
    475 #    endif
    476                             ) {
    477                                 // Settle the tapping key as *held*, since
    478                                 // HOLD_ON_OTHER_KEY_PRESS is enabled for this key.
    479                                 ac_dprintf("Tapping: End. No tap. Interfered by pressed key\n");
    480                                 process_record(&tapping_key);
    481 
    482 #    if defined(CHORDAL_HOLD)
    483                                 if (waiting_buffer_tail != waiting_buffer_head && is_tap_record(&waiting_buffer[waiting_buffer_tail])) {
    484                                     tapping_key = waiting_buffer[waiting_buffer_tail];
    485                                     // Pop tail from the queue.
    486                                     waiting_buffer_tail = (waiting_buffer_tail + 1) % WAITING_BUFFER_SIZE;
    487                                     debug_waiting_buffer();
    488                                 } else
    489 #    endif // CHORDAL_HOLD
    490                                 {
    491                                     tapping_key = (keyrecord_t){0};
    492                                 }
    493                                 debug_tapping_key();
    494 
    495 #    if defined(CHORDAL_HOLD)
    496                                 waiting_buffer_process_regular();
    497 #    endif // CHORDAL_HOLD
    498                             }
    499                     }
    500                     // enqueue
    501                     return false;
    502                 }
    503             }
    504             // tap_count > 0
    505             else {
    506                 if (IS_TAPPING_RECORD(keyp) && !event.pressed) {
    507                     ac_dprintf("Tapping: Tap release(%u)\n", tapping_key.tap.count);
    508                     keyp->tap = tapping_key.tap;
    509                     process_record(keyp);
    510                     tapping_key = *keyp;
    511                     debug_tapping_key();
    512                     return true;
    513                 } else if (is_tap_record(keyp) && event.pressed) {
    514                     if (tapping_key.tap.count > 1) {
    515                         ac_dprintf("Tapping: Start new tap with releasing last tap(>1).\n");
    516                         // unregister key
    517                         process_record(&(keyrecord_t){
    518                             .tap           = tapping_key.tap,
    519                             .event.key     = tapping_key.event.key,
    520                             .event.time    = event.time,
    521                             .event.pressed = false,
    522                             .event.type    = tapping_key.event.type,
    523 #    ifdef COMBO_ENABLE
    524                             .keycode = tapping_key.keycode,
    525 #    endif
    526                         });
    527                     } else {
    528                         ac_dprintf("Tapping: Start while last tap(1).\n");
    529                     }
    530                     tapping_key = *keyp;
    531                     waiting_buffer_scan_tap();
    532                     debug_tapping_key();
    533                     return true;
    534                 } else {
    535                     ac_dprintf("Tapping: key event while last tap(>0).\n");
    536 #    if defined(AUTO_SHIFT_ENABLE) && defined(RETRO_SHIFT)
    537                     retroshift_swap_times();
    538 #    endif
    539                     process_record(keyp);
    540                     return true;
    541                 }
    542             }
    543         }
    544         // after TAPPING_TERM
    545         else {
    546             if (tapping_key.tap.count == 0) {
    547                 ac_dprintf("Tapping: End. Timeout. Not tap(0): ");
    548                 debug_event(event);
    549                 ac_dprintf("\n");
    550                 process_record(&tapping_key);
    551                 tapping_key = (keyrecord_t){0};
    552                 debug_tapping_key();
    553                 return false;
    554             } else {
    555                 if (IS_NOEVENT(event)) {
    556                     return true;
    557                 }
    558                 if (IS_TAPPING_RECORD(keyp) && !event.pressed) {
    559                     ac_dprintf("Tapping: End. last timeout tap release(>0).");
    560                     keyp->tap = tapping_key.tap;
    561                     process_record(keyp);
    562                     tapping_key = (keyrecord_t){0};
    563                     return true;
    564                 } else if (is_tap_record(keyp) && event.pressed) {
    565                     if (tapping_key.tap.count > 1) {
    566                         ac_dprintf("Tapping: Start new tap with releasing last timeout tap(>1).\n");
    567                         // unregister key
    568                         process_record(&(keyrecord_t){
    569                             .tap           = tapping_key.tap,
    570                             .event.key     = tapping_key.event.key,
    571                             .event.time    = event.time,
    572                             .event.pressed = false,
    573                             .event.type    = tapping_key.event.type,
    574 #    ifdef COMBO_ENABLE
    575                             .keycode = tapping_key.keycode,
    576 #    endif
    577                         });
    578                     } else {
    579                         ac_dprintf("Tapping: Start while last timeout tap(1).\n");
    580                     }
    581                     tapping_key = *keyp;
    582                     waiting_buffer_scan_tap();
    583                     debug_tapping_key();
    584                     return true;
    585                 } else {
    586                     ac_dprintf("Tapping: key event while last timeout tap(>0).\n");
    587                     process_record(keyp);
    588                     return true;
    589                 }
    590             }
    591         }
    592     }
    593     // process "released" tapping key state
    594     else {
    595         if (WITHIN_TAPPING_TERM(event) || MAYBE_RETRO_SHIFTING(event, keyp)) {
    596             if (IS_NOEVENT(event)) {
    597                 // early return for tick events
    598                 return true;
    599             }
    600             if (event.pressed) {
    601                 if (IS_TAPPING_RECORD(keyp)) {
    602                     if (WITHIN_QUICK_TAP_TERM(event) && !tapping_key.tap.interrupted && tapping_key.tap.count > 0) {
    603                         // sequential tap.
    604                         keyp->tap = tapping_key.tap;
    605                         if (keyp->tap.count < 15) keyp->tap.count += 1;
    606                         ac_dprintf("Tapping: Tap press(%u)\n", keyp->tap.count);
    607                         process_record(keyp);
    608                         tapping_key = *keyp;
    609                         debug_tapping_key();
    610                         return true;
    611                     }
    612                     // FIX: start new tap again
    613                     tapping_key = *keyp;
    614                     return true;
    615                 } else if (is_tap_record(keyp)) {
    616                     // Sequential tap can be interfered with other tap key.
    617 #    if defined(FLOW_TAP_TERM)
    618                     if (flow_tap_key_if_within_term(keyp, flow_tap_prev_time)) {
    619                         tapping_key = (keyrecord_t){0};
    620                         debug_tapping_key();
    621                         return true;
    622                     }
    623 #    endif // defined(FLOW_TAP_TERM)
    624                     ac_dprintf("Tapping: Start with interfering other tap.\n");
    625                     tapping_key = *keyp;
    626                     waiting_buffer_scan_tap();
    627                     debug_tapping_key();
    628                     return true;
    629                 } else {
    630                     // should none in buffer
    631                     // FIX: interrupted when other key is pressed
    632                     tapping_key.tap.interrupted = true;
    633                     process_record(keyp);
    634                     return true;
    635                 }
    636             } else {
    637                 ac_dprintf("Tapping: other key just after tap.\n");
    638                 process_record(keyp);
    639                 return true;
    640             }
    641         } else {
    642             // Timeout - reset state machine.
    643             ac_dprintf("Tapping: End(Timeout after releasing last tap): ");
    644             debug_event(event);
    645             ac_dprintf("\n");
    646             tapping_key = (keyrecord_t){0};
    647             debug_tapping_key();
    648             return false;
    649         }
    650     }
    651 }
    652 
    653 /** \brief Waiting buffer enq
    654  *
    655  * FIXME: Needs docs
    656  */
    657 bool waiting_buffer_enq(keyrecord_t record) {
    658     if (IS_NOEVENT(record.event)) {
    659         return true;
    660     }
    661 
    662     if ((waiting_buffer_head + 1) % WAITING_BUFFER_SIZE == waiting_buffer_tail) {
    663         ac_dprintf("waiting_buffer_enq: Over flow.\n");
    664         return false;
    665     }
    666 
    667     waiting_buffer[waiting_buffer_head] = record;
    668     waiting_buffer_head                 = (waiting_buffer_head + 1) % WAITING_BUFFER_SIZE;
    669 
    670     ac_dprintf("waiting_buffer_enq: ");
    671     debug_waiting_buffer();
    672     return true;
    673 }
    674 
    675 /** \brief Waiting buffer clear
    676  *
    677  * FIXME: Needs docs
    678  */
    679 void waiting_buffer_clear(void) {
    680     waiting_buffer_head = 0;
    681     waiting_buffer_tail = 0;
    682 }
    683 
    684 /** \brief Waiting buffer typed
    685  *
    686  * FIXME: Needs docs
    687  */
    688 bool waiting_buffer_typed(keyevent_t event) {
    689     for (uint8_t i = waiting_buffer_tail; i != waiting_buffer_head; i = (i + 1) % WAITING_BUFFER_SIZE) {
    690         if (KEYEQ(event.key, waiting_buffer[i].event.key) && event.pressed != waiting_buffer[i].event.pressed) {
    691             return true;
    692         }
    693     }
    694     return false;
    695 }
    696 
    697 /** \brief Waiting buffer has anykey pressed
    698  *
    699  * FIXME: Needs docs
    700  */
    701 __attribute__((unused)) bool waiting_buffer_has_anykey_pressed(void) {
    702     for (uint8_t i = waiting_buffer_tail; i != waiting_buffer_head; i = (i + 1) % WAITING_BUFFER_SIZE) {
    703         if (waiting_buffer[i].event.pressed) return true;
    704     }
    705     return false;
    706 }
    707 
    708 /** \brief Scan buffer for tapping
    709  *
    710  * FIXME: Needs docs
    711  */
    712 void waiting_buffer_scan_tap(void) {
    713     // early return if:
    714     // - tapping already is settled
    715     // - invalid state: tapping_key released && tap.count == 0
    716     if ((tapping_key.tap.count > 0) || !tapping_key.event.pressed) {
    717         return;
    718     }
    719 
    720 #    if (defined(AUTO_SHIFT_ENABLE) && defined(RETRO_SHIFT))
    721     TAP_DEFINE_KEYCODE;
    722 #    endif
    723     for (uint8_t i = waiting_buffer_tail; i != waiting_buffer_head; i = (i + 1) % WAITING_BUFFER_SIZE) {
    724         keyrecord_t *candidate = &waiting_buffer[i];
    725         // clang-format off
    726         if (IS_EVENT(candidate->event) && KEYEQ(candidate->event.key, tapping_key.event.key) && !candidate->event.pressed && (
    727             WITHIN_TAPPING_TERM(waiting_buffer[i].event) || MAYBE_RETRO_SHIFTING(waiting_buffer[i].event, &tapping_key)
    728         )) {
    729             // clang-format on
    730             tapping_key.tap.count = 1;
    731             candidate->tap.count  = 1;
    732             process_record(&tapping_key);
    733 
    734             ac_dprintf("waiting_buffer_scan_tap: found at [%u]\n", i);
    735             debug_waiting_buffer();
    736             return;
    737         }
    738     }
    739 }
    740 
    741 #    ifdef SPECULATIVE_HOLD
    742 static void debug_speculative_keys(void) {
    743     ac_dprintf("mods = { ");
    744     for (int8_t i = 0; i < num_speculative_keys; ++i) {
    745         ac_dprintf("%02X ", speculative_keys[i].mods);
    746     }
    747     ac_dprintf("}, keys = { ");
    748     for (int8_t i = 0; i < num_speculative_keys; ++i) {
    749         ac_dprintf("%02X%02X ", speculative_keys[i].key.row, speculative_keys[i].key.col);
    750     }
    751     ac_dprintf("}\n");
    752 }
    753 
    754 // Find key in speculative_keys. Returns num_speculative_keys if not found.
    755 static int8_t speculative_keys_find(keypos_t key) {
    756     uint8_t i;
    757     for (i = 0; i < num_speculative_keys; ++i) {
    758         if (KEYEQ(speculative_keys[i].key, key)) {
    759             break;
    760         }
    761     }
    762     return i;
    763 }
    764 
    765 static void speculative_key_press(keyrecord_t *record) {
    766     if (num_speculative_keys >= SPECULATIVE_KEYS_SIZE) { // Overflow!
    767         ac_dprintf("SPECULATIVE KEYS OVERFLOW: IGNORING EVENT\n");
    768         return; // Don't trigger: speculative_keys is full.
    769     }
    770     if (speculative_keys_find(record->event.key) < num_speculative_keys) {
    771         return; // Don't trigger: key is already in speculative_keys.
    772     }
    773 
    774     const uint16_t keycode = get_record_keycode(record, false);
    775     if (!IS_QK_MOD_TAP(keycode)) {
    776         return; // Don't trigger: not a mod-tap key.
    777     }
    778 
    779     uint8_t mods = mod_config(QK_MOD_TAP_GET_MODS(keycode));
    780     if ((mods & 0x10) != 0) { // Unpack 5-bit mods to 8-bit representation.
    781         mods <<= 4;
    782     }
    783     if ((~(get_mods() | speculative_mods) & mods) == 0) {
    784         return; // Don't trigger: mods are already active.
    785     }
    786 
    787     // Don't do Speculative Hold when there are non-speculated buffered events,
    788     // since that could result in sending keys out of order.
    789     for (uint8_t i = waiting_buffer_tail; i != waiting_buffer_head; i = (i + 1) % WAITING_BUFFER_SIZE) {
    790         if (!waiting_buffer[i].tap.speculated) {
    791             return;
    792         }
    793     }
    794 
    795     if (get_speculative_hold(keycode, record)) {
    796         record->tap.speculated = true;
    797         speculative_mods |= mods;
    798         // Remember the keypos and mods associated with this key.
    799         speculative_keys[num_speculative_keys] = (speculative_key_t){
    800             .key  = record->event.key,
    801             .mods = mods,
    802         };
    803         ++num_speculative_keys;
    804 
    805         ac_dprintf("Speculative Hold: ");
    806         debug_speculative_keys();
    807     }
    808 }
    809 
    810 uint8_t get_speculative_mods(void) {
    811     return speculative_mods;
    812 }
    813 
    814 __attribute__((weak)) bool get_speculative_hold(uint16_t keycode, keyrecord_t *record) {
    815     const uint8_t mods = mod_config(QK_MOD_TAP_GET_MODS(keycode));
    816     return (mods & (MOD_LCTL | MOD_LSFT)) == (mods & (MOD_HYPR));
    817 }
    818 
    819 void speculative_key_settled(keyrecord_t *record) {
    820     if (num_speculative_keys == 0) {
    821         return; // Early return when there are no active speculative keys.
    822     }
    823 
    824     uint8_t i = speculative_keys_find(record->event.key);
    825 
    826     const uint16_t keycode = get_record_keycode(record, false);
    827     if (IS_QK_MOD_TAP(keycode) && record->tap.count == 0) { // MT hold press.
    828         if (i < num_speculative_keys) {
    829             --num_speculative_keys;
    830             const uint8_t cleared_mods = speculative_keys[i].mods;
    831 
    832             if (num_speculative_keys) {
    833                 speculative_mods &= ~cleared_mods;
    834                 // Don't call send_keyboard_report() here; allow default
    835                 // handling to reapply the mod before the next report.
    836 
    837                 // Remove the ith entry from speculative_keys.
    838                 for (uint8_t j = i; j < num_speculative_keys; ++j) {
    839                     speculative_keys[j] = speculative_keys[j + 1];
    840                 }
    841             } else {
    842                 speculative_mods = 0;
    843             }
    844 
    845             ac_dprintf("Speculative Hold: settled %02x, ", cleared_mods);
    846             debug_speculative_keys();
    847         }
    848     } else { // Tap press event; cancel speculatively-held mod.
    849         if (i >= num_speculative_keys) {
    850             i = 0;
    851         }
    852 
    853         // Clear mods for the ith key and all keys that follow.
    854         uint8_t cleared_mods = 0;
    855         for (uint8_t j = i; j < num_speculative_keys; ++j) {
    856             cleared_mods |= speculative_keys[j].mods;
    857         }
    858 
    859         num_speculative_keys = i; // Remove ith and following entries.
    860 
    861         if ((prev_speculative_mods & cleared_mods) != 0) {
    862 #        ifdef DUMMY_MOD_NEUTRALIZER_KEYCODE
    863             neutralize_flashing_modifiers(get_mods() | prev_speculative_mods);
    864 #        endif // DUMMY_MOD_NEUTRALIZER_KEYCODE
    865         }
    866 
    867         if (num_speculative_keys) {
    868             speculative_mods &= ~cleared_mods;
    869         } else {
    870             speculative_mods = 0;
    871         }
    872 
    873         send_keyboard_report();
    874         wait_ms(TAP_CODE_DELAY);
    875 
    876         ac_dprintf("Speculative Hold: canceled %02x, ", cleared_mods);
    877         debug_speculative_keys();
    878     }
    879 }
    880 #    endif // SPECULATIVE_HOLD
    881 
    882 #    if defined(CHORDAL_HOLD) || defined(FLOW_TAP_TERM)
    883 static void registered_taps_add(keypos_t key) {
    884     if (num_registered_taps >= REGISTERED_TAPS_SIZE) {
    885         ac_dprintf("TAPS OVERFLOW: CLEAR ALL STATES\n");
    886         clear_keyboard();
    887         num_registered_taps = 0;
    888     }
    889 
    890     registered_taps[num_registered_taps] = key;
    891     ++num_registered_taps;
    892 }
    893 
    894 static int8_t registered_tap_find(keypos_t key) {
    895     for (int8_t i = 0; i < num_registered_taps; ++i) {
    896         if (KEYEQ(registered_taps[i], key)) {
    897             return i;
    898         }
    899     }
    900     return -1;
    901 }
    902 
    903 static void registered_taps_del_index(uint8_t i) {
    904     if (i < num_registered_taps) {
    905         --num_registered_taps;
    906         if (i < num_registered_taps) {
    907             registered_taps[i] = registered_taps[num_registered_taps];
    908         }
    909     }
    910 }
    911 
    912 static void debug_registered_taps(void) {
    913     ac_dprintf("registered_taps = { ");
    914     for (int8_t i = 0; i < num_registered_taps; ++i) {
    915         ac_dprintf("%02X%02X ", registered_taps[i].row, registered_taps[i].col);
    916     }
    917     ac_dprintf("}\n");
    918 }
    919 
    920 #    endif // defined(CHORDAL_HOLD) || defined(FLOW_TAP_TERM)
    921 
    922 #    ifdef CHORDAL_HOLD
    923 __attribute__((weak)) bool get_chordal_hold(uint16_t tap_hold_keycode, keyrecord_t *tap_hold_record, uint16_t other_keycode, keyrecord_t *other_record) {
    924     return get_chordal_hold_default(tap_hold_record, other_record);
    925 }
    926 
    927 bool get_chordal_hold_default(keyrecord_t *tap_hold_record, keyrecord_t *other_record) {
    928     if (tap_hold_record->event.type != KEY_EVENT || other_record->event.type != KEY_EVENT) {
    929         return true; // Return true on combos or other non-key events.
    930     }
    931 
    932     char tap_hold_hand = chordal_hold_handedness(tap_hold_record->event.key);
    933     if (tap_hold_hand == '*') {
    934         return true;
    935     }
    936     char other_hand = chordal_hold_handedness(other_record->event.key);
    937     return other_hand == '*' || tap_hold_hand != other_hand;
    938 }
    939 
    940 __attribute__((weak)) char chordal_hold_handedness(keypos_t key) {
    941     return (char)pgm_read_byte(&chordal_hold_layout[key.row][key.col]);
    942 }
    943 
    944 static uint8_t waiting_buffer_find_chordal_hold_tap(void) {
    945     keyrecord_t *prev         = &tapping_key;
    946     uint16_t     prev_keycode = get_record_keycode(&tapping_key, false);
    947     uint8_t      first_tap    = WAITING_BUFFER_SIZE;
    948     for (uint8_t i = waiting_buffer_tail; i != waiting_buffer_head; i = (i + 1) % WAITING_BUFFER_SIZE) {
    949         keyrecord_t   *cur         = &waiting_buffer[i];
    950         const uint16_t cur_keycode = get_record_keycode(cur, false);
    951         if (!cur->event.pressed || !is_mt_or_lt(prev_keycode)) {
    952             break;
    953         } else if (get_chordal_hold(prev_keycode, prev, cur_keycode, cur)) {
    954             first_tap = i; // Track one index past the latest hold.
    955         }
    956         prev         = cur;
    957         prev_keycode = cur_keycode;
    958     }
    959     return first_tap;
    960 }
    961 
    962 static void waiting_buffer_chordal_hold_taps_until(keypos_t key) {
    963     while (waiting_buffer_tail != waiting_buffer_head) {
    964         keyrecord_t *record = &waiting_buffer[waiting_buffer_tail];
    965         ac_dprintf("waiting_buffer_chordal_hold_taps_until: processing [%u]\n", waiting_buffer_tail);
    966         if (record->event.pressed && is_tap_record(record)) {
    967             record->tap.count = 1;
    968             registered_taps_add(record->event.key);
    969         }
    970         process_record(record);
    971         waiting_buffer_tail = (waiting_buffer_tail + 1) % WAITING_BUFFER_SIZE;
    972 
    973         if (KEYEQ(key, record->event.key) && record->event.pressed) {
    974             break;
    975         }
    976     }
    977 }
    978 
    979 static void waiting_buffer_process_regular(void) {
    980     for (; waiting_buffer_tail != waiting_buffer_head; waiting_buffer_tail = (waiting_buffer_tail + 1) % WAITING_BUFFER_SIZE) {
    981         if (is_tap_record(&waiting_buffer[waiting_buffer_tail])) {
    982             break; // Stop once a tap-hold key event is reached.
    983         }
    984         ac_dprintf("waiting_buffer_process_regular: processing [%u]\n", waiting_buffer_tail);
    985         process_record(&waiting_buffer[waiting_buffer_tail]);
    986     }
    987     debug_waiting_buffer();
    988 }
    989 #    endif // CHORDAL_HOLD
    990 
    991 #    ifdef FLOW_TAP_TERM
    992 void flow_tap_update_last_event(keyrecord_t *record) {
    993     const uint16_t keycode = get_record_keycode(record, false);
    994     // Don't update while a tap-hold key is unsettled.
    995     if (record->tap.count == 0 && (waiting_buffer_tail != waiting_buffer_head || (tapping_key.event.pressed && tapping_key.tap.count == 0))) {
    996         return;
    997     }
    998     // Ignore releases of modifiers and held layer switches.
    999     if (!record->event.pressed) {
   1000         switch (keycode) {
   1001             case MODIFIER_KEYCODE_RANGE:
   1002             case QK_MOMENTARY ... QK_MOMENTARY_MAX:
   1003             case QK_LAYER_TAP_TOGGLE ... QK_LAYER_TAP_TOGGLE_MAX:
   1004 #        ifndef NO_ACTION_ONESHOT // Ignore one-shot keys.
   1005             case QK_ONE_SHOT_MOD ... QK_ONE_SHOT_MOD_MAX:
   1006             case QK_ONE_SHOT_LAYER ... QK_ONE_SHOT_LAYER_MAX:
   1007 #        endif                  // NO_ACTION_ONESHOT
   1008 #        ifdef TRI_LAYER_ENABLE // Ignore Tri Layer keys.
   1009             case QK_TRI_LAYER_LOWER:
   1010             case QK_TRI_LAYER_UPPER:
   1011 #        endif // TRI_LAYER_ENABLE
   1012                 return;
   1013             case QK_MODS ... QK_MODS_MAX:
   1014                 if (QK_MODS_GET_BASIC_KEYCODE(keycode) == KC_NO) {
   1015                     return;
   1016                 }
   1017                 break;
   1018             case QK_MOD_TAP ... QK_MOD_TAP_MAX:
   1019             case QK_LAYER_TAP ... QK_LAYER_TAP_MAX:
   1020                 if (record->tap.count == 0) {
   1021                     return;
   1022                 }
   1023                 break;
   1024         }
   1025     }
   1026 
   1027     flow_tap_prev_keycode = keycode;
   1028     flow_tap_prev_time    = record->event.time;
   1029     flow_tap_expired      = false;
   1030 }
   1031 
   1032 static bool flow_tap_key_if_within_term(keyrecord_t *record, uint16_t prev_time) {
   1033     const uint16_t idle_time = TIMER_DIFF_16(record->event.time, prev_time);
   1034     if (flow_tap_expired || idle_time >= 500) {
   1035         return false;
   1036     }
   1037 
   1038     const uint16_t keycode = get_record_keycode(record, false);
   1039     if (is_mt_or_lt(keycode)) {
   1040         uint16_t term = get_flow_tap_term(keycode, record, flow_tap_prev_keycode);
   1041         if (term > 500) {
   1042             term = 500;
   1043         }
   1044         if (idle_time < term) {
   1045             debug_event(record->event);
   1046             ac_dprintf(" within flow tap term (%u < %u) considered a tap\n", idle_time, term);
   1047             record->tap.count = 1;
   1048             registered_taps_add(record->event.key);
   1049             debug_registered_taps();
   1050             process_record(record);
   1051             return true;
   1052         }
   1053     }
   1054     return false;
   1055 }
   1056 
   1057 // Checks both flow_tap_expired flag and elapsed time to determine
   1058 // if the key is within the flow tap term.
   1059 bool within_flow_tap_term(uint16_t keycode, keyrecord_t *record) {
   1060     uint16_t term = get_flow_tap_term(keycode, record, flow_tap_prev_keycode);
   1061     return !flow_tap_expired && TIMER_DIFF_16(record->event.time, flow_tap_prev_time) <= term;
   1062 }
   1063 
   1064 // By default, enable Flow Tap for the keys in the main alphas area and Space.
   1065 // This should work reasonably even if the layout is remapped on the host to an
   1066 // alt layout or international layout (e.g. Dvorak or AZERTY), where these same
   1067 // key positions are mostly used for typing letters.
   1068 __attribute__((weak)) bool is_flow_tap_key(uint16_t keycode) {
   1069     if ((get_mods() & (MOD_MASK_CG | MOD_BIT_LALT)) != 0) {
   1070         return false; // Disable Flow Tap on hotkeys.
   1071     }
   1072     switch (get_tap_keycode(keycode)) {
   1073         case KC_SPC:
   1074         case KC_A ... KC_Z:
   1075         case KC_DOT:
   1076         case KC_COMM:
   1077         case KC_SCLN:
   1078         case KC_SLSH:
   1079             return true;
   1080     }
   1081     return false;
   1082 }
   1083 
   1084 __attribute__((weak)) uint16_t get_flow_tap_term(uint16_t keycode, keyrecord_t *record, uint16_t prev_keycode) {
   1085     if (is_flow_tap_key(keycode) && is_flow_tap_key(prev_keycode)) {
   1086         return FLOW_TAP_TERM;
   1087     }
   1088     return 0;
   1089 }
   1090 #    endif // FLOW_TAP_TERM
   1091 
   1092 /** \brief Logs tapping key if ACTION_DEBUG is enabled. */
   1093 static void debug_tapping_key(void) {
   1094     ac_dprintf("TAPPING_KEY=");
   1095     debug_record(tapping_key);
   1096     ac_dprintf("\n");
   1097 }
   1098 
   1099 /** \brief Logs waiting buffer if ACTION_DEBUG is enabled. */
   1100 static void debug_waiting_buffer(void) {
   1101     ac_dprintf("{");
   1102     for (uint8_t i = waiting_buffer_tail; i != waiting_buffer_head; i = (i + 1) % WAITING_BUFFER_SIZE) {
   1103         ac_dprintf(" [%u]=", i);
   1104         debug_record(waiting_buffer[i]);
   1105     }
   1106     ac_dprintf("}\n");
   1107 }
   1108 
   1109 #endif