qmk_firmware/users/konstantin/tap_dance.c

#include "tap_dance.h"
#include "konstantin.h"

#define ACTION_TAP_DANCE_DOUBLE_MOD(mod1, mod2) {                   \
    .fn        = { td_double_mod_each, NULL, td_double_mod_reset }, \
    .user_data = &(qk_tap_dance_pair_t){ mod1, mod2 },              \
  }

void td_double_mod_each(qk_tap_dance_state_t *state, void *user_data) {
  qk_tap_dance_pair_t *data = (qk_tap_dance_pair_t *)user_data;

  // Single tap → mod1, double tap → mod2, triple tap etc. → mod1+mod2
  if (state->count == 1 || state->count == 3) {
    register_code(data->kc1);
  } else if (state->count == 2) {
    unregister_code(data->kc1);
    register_code(data->kc2);
  }
  // Prevent tap dance from sending the mods as weak mods
  state->weak_mods &= ~(MOD_BIT(data->kc1) | MOD_BIT(data->kc2));
}

void td_double_mod_reset(qk_tap_dance_state_t *state, void *user_data) {
  qk_tap_dance_pair_t *data = (qk_tap_dance_pair_t *)user_data;

  if (state->count == 1 || state->count >= 3) {
    unregister_code(data->kc1);
  }
  if (state->count >= 2) {
    unregister_code(data->kc2);
  }
}

#define ACTION_TAP_DANCE_MOD_LAYER(mod, layer) {                  \
    .fn        = { td_mod_layer_each, NULL, td_mod_layer_reset }, \
    .user_data = &(qk_tap_dance_dual_role_t){ mod, layer },       \
  }

void td_mod_layer_each(qk_tap_dance_state_t *state, void *user_data) {
  qk_tap_dance_dual_role_t *data = (qk_tap_dance_dual_role_t *)user_data;

  // Single tap → mod, double tap → layer, triple tap etc. → mod+layer
  if (state->count == 1 || state->count == 3) {
    register_code(data->kc);
  } else if (state->count == 2) {
    unregister_code(data->kc);
    // Prevent tap dance from sending the mod as a weak mod
    state->weak_mods &= ~MOD_BIT(data->kc);
    layer_on(data->layer);
  }
}

void td_mod_layer_reset(qk_tap_dance_state_t *state, void *user_data) {
  qk_tap_dance_dual_role_t *data = (qk_tap_dance_dual_role_t *)user_data;

  if (state->count == 1 || state->count >= 3) {
    unregister_code(data->kc);
  }
  if (state->count >= 2) {
    layer_off(data->layer);
  }
}

#define ACTION_TAP_DANCE_LAYER_MOD(layer, mod) {                  \
    .fn        = { td_layer_mod_each, NULL, td_layer_mod_reset }, \
    .user_data = &(qk_tap_dance_layer_mod_t){ layer, mod, 0, 0 }, \
  }

typedef struct {
  uint8_t  layer;
  uint16_t kc;
  bool     layer_on;  // Layer state when tap dance started
  bool     started;
} qk_tap_dance_layer_mod_t;

void td_layer_mod_each(qk_tap_dance_state_t *state, void *user_data) {
  qk_tap_dance_layer_mod_t *data = (qk_tap_dance_layer_mod_t *)user_data;
  if (!data->started) {
    data->layer_on = IS_LAYER_ON(data->layer);
    data->started = true;
  }

  // Single tap → layer, double tap → mod, triple tap etc. → layer+mod
  if (state->count == 1 || state->count == 3) {
    layer_on(data->layer);
  } else if (state->count == 2) {
    if (!data->layer_on) {
      layer_off(data->layer);
    }
    register_code(data->kc);
  }
}

void td_layer_mod_reset(qk_tap_dance_state_t *state, void *user_data) {
  qk_tap_dance_layer_mod_t *data = (qk_tap_dance_layer_mod_t *)user_data;

  if ((state->count == 1 || state->count >= 3) && !data->layer_on) {
    layer_off(data->layer);
  }
  if (state->count >= 2) {
    unregister_code(data->kc);
  }

  data->started = false;
}

qk_tap_dance_action_t tap_dance_actions[] = {
  [TD_DST_A_R] = ACTION_TAP_DANCE_DOUBLE(DST_ADD, DST_REM),

  [TD_RAL_LAL] = ACTION_TAP_DANCE_DOUBLE_MOD(KC_RALT, KC_LALT),
  [TD_RAL_RGU] = ACTION_TAP_DANCE_DOUBLE_MOD(KC_RALT, KC_RGUI),
  [TD_RCT_RSF] = ACTION_TAP_DANCE_DOUBLE_MOD(KC_RCTL, KC_RSFT),

  [TD_LSFT_FN] = ACTION_TAP_DANCE_MOD_LAYER(KC_LSFT, L_FN),
  [TD_RCTL_FN] = ACTION_TAP_DANCE_MOD_LAYER(KC_RCTL, L_FN),
  [TD_FN_RCTL] = ACTION_TAP_DANCE_LAYER_MOD(L_FN, KC_RCTL),
};