Generalize Tap Dance Layer functions (#6629)

* made tapdance dual_role general

* updated original dual_role functionality

* added toggling layer example

* Fix dual role and add alias

* Update docs about new layer tap dances

* Fix up based on feedback

.vscode/settings.json

@@ -12,6 +12,8 @@
       "*.c": "c",
       "*.cpp": "cpp",
       "*.hpp": "cpp",
-        "xstddef": "c"
+      "xstddef": "c",
+      "type_traits": "c",
+      "utility": "c"
     }
 }

docs/feature_tap_dance.md

@@ -30,7 +30,9 @@ Next, you will want to define some tap-dance keys, which is easiest to do with t
 After this, you'll want to use the `tap_dance_actions` array to specify what actions shall be taken when a tap-dance key is in action. Currently, there are five possible options:
 
 * `ACTION_TAP_DANCE_DOUBLE(kc1, kc2)`: Sends the `kc1` keycode when tapped once, `kc2` otherwise. When the key is held, the appropriate keycode is registered: `kc1` when pressed and held, `kc2` when tapped once, then pressed and held.
-* `ACTION_TAP_DANCE_DUAL_ROLE(kc, layer)`: Sends the `kc` keycode when tapped once, or moves to `layer`. (this functions like the `TO` layer keycode).
+* `ACTION_TAP_DANCE_LAYER_MOVE(kc, layer)`: Sends the `kc` keycode when tapped once, or moves to `layer`. (this functions like the `TO` layer keycode).
+    * This is the same as `ACTION_TAP_DANCE_DUAL_ROLE`, but renamed to something that is clearer about its functionality.  Both names will work.
+* `ACTION_TAP_DANCE_LAYER_TOGGLE(kc, layer)`: Sends the `kc` keycode when tapped once, or toggles the state of `layer`. (this functions like the `TG` layer keycode).
 * `ACTION_TAP_DANCE_FN(fn)`: Calls the specified function - defined in the user keymap - with the final tap count of the tap dance action.
 * `ACTION_TAP_DANCE_FN_ADVANCED(on_each_tap_fn, on_dance_finished_fn, on_dance_reset_fn)`: Calls the first specified function - defined in the user keymap - on every tap, the second function when the dance action finishes (like the previous option), and the last function when the tap dance action resets.
 * `ACTION_TAP_DANCE_FN_ADVANCED_TIME(on_each_tap_fn, on_dance_finished_fn, on_dance_reset_fn, tap_specific_tapping_term)`: This functions identically to the `ACTION_TAP_DANCE_FN_ADVANCED` function, but uses a custom tapping term for it, instead of the predefined `TAPPING_TERM`.

quantum/process_keycode/process_tap_dance.c

@@ -71,7 +71,7 @@ void qk_tap_dance_dual_role_finished(qk_tap_dance_state_t *state, void *user_dat
     if (state->count == 1) {
         register_code16(pair->kc);
     } else if (state->count == 2) {
-        layer_move(pair->layer);
+        pair->layer_function(pair->layer);
     }
 }
 

quantum/process_keycode/process_tap_dance.h

@@ -56,13 +56,19 @@ typedef struct {
 typedef struct {
     uint16_t kc;
     uint8_t  layer;
+    void (*layer_function)(uint8_t);
 } qk_tap_dance_dual_role_t;
 
 #    define ACTION_TAP_DANCE_DOUBLE(kc1, kc2) \
         { .fn = {qk_tap_dance_pair_on_each_tap, qk_tap_dance_pair_finished, qk_tap_dance_pair_reset}, .user_data = (void *)&((qk_tap_dance_pair_t){kc1, kc2}), }
 
 #    define ACTION_TAP_DANCE_DUAL_ROLE(kc, layer) \
-        { .fn = {qk_tap_dance_dual_role_on_each_tap, qk_tap_dance_dual_role_finished, qk_tap_dance_dual_role_reset}, .user_data = (void *)&((qk_tap_dance_dual_role_t){kc, layer}), }
+        { .fn = { qk_tap_dance_dual_role_on_each_tap, qk_tap_dance_dual_role_finished, qk_tap_dance_dual_role_reset }, .user_data = (void *)&((qk_tap_dance_dual_role_t) { kc, layer, layer_move }),  }
+
+#    define ACTION_TAP_DANCE_TOGGLE_LAYER(kc, layer) \
+        { .fn = { NULL, qk_tap_dance_dual_role_finished, qk_tap_dance_dual_role_reset }, .user_data = (void *)&((qk_tap_dance_dual_role_t) { kc, layer, layer_invert }), }
+
+#    define ACTION_TAP_DANCE_LAYER_MOVE(kc, layer) ACTION_TAP_DANCE_DUAL_ROLE(kc, layer)
 
 #    define ACTION_TAP_DANCE_FN(user_fn) \
         { .fn = {NULL, user_fn, NULL}, .user_data = NULL, }
@@ -73,6 +79,8 @@ typedef struct {
 #    define ACTION_TAP_DANCE_FN_ADVANCED_TIME(user_fn_on_each_tap, user_fn_on_dance_finished, user_fn_on_dance_reset, tap_specific_tapping_term) \
         { .fn = {user_fn_on_each_tap, user_fn_on_dance_finished, user_fn_on_dance_reset}, .user_data = NULL, .custom_tapping_term = tap_specific_tapping_term, }
 
+
+
 extern qk_tap_dance_action_t tap_dance_actions[];
 
 /* To be used internally */