Implement and document TAPPING_FORCE_HOLD_PER_KEY (#7859)

* Implement and document TAPPING_FORCE_HOLD_PER_KEY

* Added "record" parameter to "get_tapping_force_hold"

* Correct typo -- remove 'IGNORE_' from 'IGNORE_TAPPING_FORCE_HOLD_PER_KEY'

Co-authored-by: GeorgeKoenig <35542036+GeorgeKoenig@users.noreply.github.com>

3 files changed, 51 insertions, 2 deletions

diff --git a/docs/config_options.md b/docs/config_options.md
index 0b83ed9e4a..6df0823356 100644
--- a/docs/config_options.md
+++ b/docs/config_options.md
@@ -149,6 +149,8 @@ If you define these options you will enable the associated feature, which may in
   * makes it possible to use a dual role key as modifier shortly after having been tapped
   * See [Hold after tap](feature_advanced_keycodes.md#tapping-force-hold)
   * Breaks any Tap Toggle functionality (`TT` or the One Shot Tap Toggle)
+* `#define TAPPING_FORCE_HOLD_PER_KEY`
+  * enables handling for per key `TAPPING_FORCE_HOLD` settings
 * `#define LEADER_TIMEOUT 300`
   * how long before the leader key times out
     * If you're having issues finishing the sequence before it times out, you may need to increase the timeout setting. Or you may want to enable the `LEADER_PER_KEY_TIMING` option, which resets the timeout after each key is tapped.
diff --git a/docs/feature_advanced_keycodes.md b/docs/feature_advanced_keycodes.md
index ec3807f400..ebb24dc990 100644
--- a/docs/feature_advanced_keycodes.md
+++ b/docs/feature_advanced_keycodes.md
@@ -291,6 +291,25 @@ Normally, this would send `X` (`SHIFT`+`x`). With `Ignore Mod Tap Interrupt` ena
 
 ?> If you have `Permissive Hold` enabled, as well, this will modify how both work. The regular key has the modifier added if the first key is released first or if both keys are held longer than the `TAPPING_TERM`.
 
+For more granular control of this feature, you can add the following to your `config.h`:
+
+```c
+#define IGNORE_MOD_TAP_INTERRUPT_PER_KEY
+```
+
+You can then add the following function to your keymap:
+
+```c
+bool get_ignore_mod_tap_interrupt(uint16_t keycode) {
+  switch (keycode) {
+    case SFT_T(KC_SPC):
+      return true;
+    default:
+      return false;
+  }
+}
+```
+
 ## Tapping Force Hold
 
 To enable `tapping force hold`, add the following to your `config.h`: 
@@ -315,6 +334,25 @@ With `TAPPING_FORCE_HOLD`, the second press will be interpreted as a Shift, allo
 
 !> `TAPPING_FORCE_HOLD` will break anything that uses tapping toggles (Such as the `TT` layer keycode, and the One Shot Tapping Toggle).
 
+For more granular control of this feature, you can add the following to your `config.h`:
+
+```c
+#define TAPPING_FORCE_HOLD_PER_KEY
+```
+
+You can then add the following function to your keymap:
+
+```c
+bool get_tapping_force_hold(uint16_t keycode, keyrecord_t *record) {
+  switch (keycode) {
+    case LT(1, KC_BSPC):
+      return true;
+    default:
+      return false;
+  }
+}
+```
+
 ## Retro Tapping
 
 To enable `retro tapping`, add the following to your `config.h`: 
diff --git a/tmk_core/common/action_tapping.c b/tmk_core/common/action_tapping.c
index 8531dff360..c0f1f694b7 100644
--- a/tmk_core/common/action_tapping.c
+++ b/tmk_core/common/action_tapping.c
@@ -27,6 +27,10 @@ __attribute__((weak)) uint16_t get_tapping_term(uint16_t keycode) { return TAPPI
 #        define WITHIN_TAPPING_TERM(e) (TIMER_DIFF_16(e.time, tapping_key.event.time) < TAPPING_TERM)
 #    endif
 
+#    ifdef TAPPING_FORCE_HOLD_PER_KEY
+__attribute__((weak)) bool get_tapping_force_hold(uint16_t keycode, keyrecord_t *record) { return false; }
+#    endif
+
 static keyrecord_t tapping_key                         = {};
 static keyrecord_t waiting_buffer[WAITING_BUFFER_SIZE] = {};
 static uint8_t     waiting_buffer_head                 = 0;
@@ -232,8 +236,13 @@ bool process_tapping(keyrecord_t *keyp) {
         if (WITHIN_TAPPING_TERM(event)) {
             if (event.pressed) {
                 if (IS_TAPPING_KEY(event.key)) {
-#    ifndef TAPPING_FORCE_HOLD
-                    if (!tapping_key.tap.interrupted && tapping_key.tap.count > 0) {
+//#    ifndef TAPPING_FORCE_HOLD
+#    if !defined(TAPPING_FORCE_HOLD) || defined(TAPPING_FORCE_HOLD_PER_KEY)
+                    if (
+#        ifdef TAPPING_FORCE_HOLD_PER_KEY
+                        !get_tapping_force_hold(get_event_keycode(tapping_key.event), keyp) &&
+#        endif
+                        !tapping_key.tap.interrupted && tapping_key.tap.count > 0) {
                         // sequential tap.
                         keyp->tap = tapping_key.tap;
                         if (keyp->tap.count < 15) keyp->tap.count += 1;