1 files changed, 136 insertions, 0 deletions
diff --git a/quantum/process_keycode/process_tap_dance.c b/quantum/process_keycode/process_tap_dance.c
new file mode 100644
index 0000000000..6ae362c4c2
--- /dev/null
+++ b/quantum/process_keycode/process_tap_dance.c
@@ -0,0 +1,136 @@
+#include "quantum.h"
+#include "action_tapping.h"
+
+static uint16_t last_td;
+static int8_t highest_td = -1;
+
+void qk_tap_dance_pair_finished (qk_tap_dance_state_t *state, void *user_data) {
+  qk_tap_dance_pair_t *pair = (qk_tap_dance_pair_t *)user_data;
+
+  if (state->count == 1) {
+    register_code16 (pair->kc1);
+  } else if (state->count == 2) {
+    register_code16 (pair->kc2);
+  }
+}
+
+void qk_tap_dance_pair_reset (qk_tap_dance_state_t *state, void *user_data) {
+  qk_tap_dance_pair_t *pair = (qk_tap_dance_pair_t *)user_data;
+
+  if (state->count == 1) {
+    unregister_code16 (pair->kc1);
+  } else if (state->count == 2) {
+    unregister_code16 (pair->kc2);
+  }
+}
+
+static inline void _process_tap_dance_action_fn (qk_tap_dance_state_t *state,
+                                                 void *user_data,
+                                                 qk_tap_dance_user_fn_t fn)
+{
+  if (fn) {
+    fn(state, user_data);
+  }
+}
+
+static inline void process_tap_dance_action_on_each_tap (qk_tap_dance_action_t *action)
+{
+  _process_tap_dance_action_fn (&action->state, action->user_data, action->fn.on_each_tap);
+}
+
+static inline void process_tap_dance_action_on_dance_finished (qk_tap_dance_action_t *action)
+{
+  if (action->state.finished)
+    return;
+  action->state.finished = true;
+  _process_tap_dance_action_fn (&action->state, action->user_data, action->fn.on_dance_finished);
+}
+
+static inline void process_tap_dance_action_on_reset (qk_tap_dance_action_t *action)
+{
+  _process_tap_dance_action_fn (&action->state, action->user_data, action->fn.on_reset);
+}
+
+bool process_tap_dance(uint16_t keycode, keyrecord_t *record) {
+  uint16_t idx = keycode - QK_TAP_DANCE;
+  qk_tap_dance_action_t *action;
+
+  if (last_td && last_td != keycode) {
+    (&tap_dance_actions[last_td - QK_TAP_DANCE])->state.interrupted = true;
+  }
+
+  switch(keycode) {
+  case QK_TAP_DANCE ... QK_TAP_DANCE_MAX:
+    if ((int16_t)idx > highest_td)
+      highest_td = idx;
+    action = &tap_dance_actions[idx];
+
+    action->state.pressed = record->event.pressed;
+    if (record->event.pressed) {
+      action->state.keycode = keycode;
+      action->state.count++;
+      action->state.timer = timer_read();
+      process_tap_dance_action_on_each_tap (action);
+
+      if (last_td && last_td != keycode) {
+        qk_tap_dance_action_t *paction = &tap_dance_actions[last_td - QK_TAP_DANCE];
+        paction->state.interrupted = true;
+        process_tap_dance_action_on_dance_finished (paction);
+        reset_tap_dance (&paction->state);
+      }
+
+      last_td = keycode;
+    }
+
+    break;
+
+  default:
+    if (!record->event.pressed)
+      return true;
+
+    if (highest_td == -1)
+      return true;
+
+    for (int i = 0; i <= highest_td; i++) {
+      action = &tap_dance_actions[i];
+      if (action->state.count == 0)
+        continue;
+      action->state.interrupted = true;
+      process_tap_dance_action_on_dance_finished (action);
+      reset_tap_dance (&action->state);
+    }
+    break;
+  }
+
+  return true;
+}
+
+void matrix_scan_tap_dance () {
+  if (highest_td == -1)
+    return;
+
+  for (int i = 0; i <= highest_td; i++) {
+    qk_tap_dance_action_t *action = &tap_dance_actions[i];
+
+    if (action->state.count && timer_elapsed (action->state.timer) > TAPPING_TERM) {
+      process_tap_dance_action_on_dance_finished (action);
+      reset_tap_dance (&action->state);
+    }
+  }
+}
+
+void reset_tap_dance (qk_tap_dance_state_t *state) {
+  qk_tap_dance_action_t *action;
+
+  if (state->pressed)
+    return;
+
+  action = &tap_dance_actions[state->keycode - QK_TAP_DANCE];
+
+  process_tap_dance_action_on_reset (action);
+
+  state->count = 0;
+  state->interrupted = false;
+  state->finished = false;
+  last_td = 0;
+}