Custom Tapping Term per key (#5009)

* Add customizable tapping terms

* Add Documentation

* Fix function

* Fixes

* It's not a pointer

* Add debugging output

* Update documentation to be at least vaguely accurate

* Use `get_tapping_term(tapping_key.event)` instead

`e` doesn't include column and row information, properly. It registers as 255, regardless of the actual keypress.

However `tapping_key.event` actually gives the correct column and row information.  It appears be the correct structure to use. 

In fact, it looks like the issue is that `e` is actually the "TICK" structure, as defined in keyboard.h

* Use variable tapping term value rather than define

* Silly drashna - tapping_key.event, not event

* add get_event_keycode() function

* Fix typo

Co-Authored-By: drashna <drashna@live.com>

* Remove post_process_record_quantum since it's the wrong PR

* Update quantum/quantum.c

Co-Authored-By: drashna <drashna@live.com>

* Better handle ifdef statement for permissive hold

Since we can't be sure that tapping term is actually 500

* Update quantum.c comments based on feedback

* Clean up get_tapping_term function

Clean up function so that users don't need to call the event function, and instead only check the keycode

* Add ability to run functionality on and off

* Make ifdef's more compact

2 files changed, 24 insertions, 10 deletions

diff --git a/quantum/quantum.c b/quantum/quantum.c
index 8c928441c5..48c338fc85 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -225,27 +225,39 @@ static uint16_t scs_timer[2] = {0, 0};
  */
 static bool grave_esc_was_shifted = false;
 
-bool process_record_quantum(keyrecord_t *record) {
+/* Convert record into usable keycode via the contained event. */
+uint16_t get_record_keycode(keyrecord_t *record) {
+  return get_event_keycode(record->event);
+}
 
-  /* This gets the keycode from the key pressed */
-  keypos_t key = record->event.key;
-  uint16_t keycode;
+
+/* Convert event into usable keycode. Checks the layer cache to ensure that it
+ * retains the correct keycode after a layer change, if the key is still pressed.
+ */
+uint16_t get_event_keycode(keyevent_t event) {
 
   #if !defined(NO_ACTION_LAYER) && !defined(STRICT_LAYER_RELEASE)
     /* TODO: Use store_or_get_action() or a similar function. */
     if (!disable_action_cache) {
       uint8_t layer;
 
-      if (record->event.pressed) {
-        layer = layer_switch_get_layer(key);
-        update_source_layers_cache(key, layer);
+      if (event.pressed) {
+        layer = layer_switch_get_layer(event.key);
+        update_source_layers_cache(event.key, layer);
       } else {
-        layer = read_source_layers_cache(key);
+        layer = read_source_layers_cache(event.key);
       }
-      keycode = keymap_key_to_keycode(layer, key);
+      return keymap_key_to_keycode(layer, event.key);
     } else
   #endif
-    keycode = keymap_key_to_keycode(layer_switch_get_layer(key), key);
+    return keymap_key_to_keycode(layer_switch_get_layer(event.key), event.key);
+}
+
+/* Main keycode processing function. Hands off handling to other functions,
+ * then processes internal Quantum keycodes, then processes ACTIONs.
+ */
+bool process_record_quantum(keyrecord_t *record) {
+    uint16_t keycode = get_record_keycode(record);
 
     // This is how you use actions here
     // if (keycode == KC_LEAD) {
diff --git a/quantum/quantum.h b/quantum/quantum.h
index c12ac9ab8a..d0b2bedb1b 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -224,6 +224,8 @@ void matrix_init_kb(void);
 void matrix_scan_kb(void);
 void matrix_init_user(void);
 void matrix_scan_user(void);
+uint16_t get_record_keycode(keyrecord_t *record);
+uint16_t get_event_keycode(keyevent_t event);
 bool process_action_kb(keyrecord_t *record);
 bool process_record_kb(uint16_t keycode, keyrecord_t *record);
 bool process_record_user(uint16_t keycode, keyrecord_t *record);