From 66e40529aa9271c76d207fb8190ad76bb5cf8d6b Mon Sep 17 00:00:00 2001
From: Martin Sandiford <ms@mcdev.com.au>
Date: Fri, 27 Apr 2018 05:40:03 +0930
Subject: [PATCH] Change handling of adjust layer to make it more LT(...)
 friendly. (#1625)

* Change handling of adjust layer to make it more LT(...) friendly.

* Update based on feedback from drashna.

* Change handling of adjust layer to make it more LT(...) friendly.  This reworks handling to make it a little more friendly to include in keymaps.
---
 keyboards/planck/keymaps/default/keymap.c | 29 ++++++-----------------
 quantum/quantum.c                         | 12 ++++++----
 quantum/quantum.h                         |  1 +
 3 files changed, 15 insertions(+), 27 deletions(-)

diff --git a/keyboards/planck/keymaps/default/keymap.c b/keyboards/planck/keymaps/default/keymap.c
index 04fc33640..b13557eee 100644
--- a/keyboards/planck/keymaps/default/keymap.c
+++ b/keyboards/planck/keymaps/default/keymap.c
@@ -34,12 +34,13 @@ enum planck_keycodes {
   COLEMAK,
   DVORAK,
   PLOVER,
-  LOWER,
-  RAISE,
   BACKLIT,
   EXT_PLV
 };
 
+#define LOWER MO(_LOWER)
+#define RAISE MO(_RAISE)
+
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 
 /* Qwerty
@@ -177,6 +178,10 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
   float plover_gb_song[][2]  = SONG(PLOVER_GOODBYE_SOUND);
 #endif
 
+uint32_t layer_state_set_user(uint32_t state) {
+  return update_tri_layer_state(state, _LOWER, _RAISE, _ADJUST);
+}
+
 bool process_record_user(uint16_t keycode, keyrecord_t *record) {
   switch (keycode) {
     case QWERTY:
@@ -198,26 +203,6 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
       }
       return false;
       break;
-    case LOWER:
-      if (record->event.pressed) {
-        layer_on(_LOWER);
-        update_tri_layer(_LOWER, _RAISE, _ADJUST);
-      } else {
-        layer_off(_LOWER);
-        update_tri_layer(_LOWER, _RAISE, _ADJUST);
-      }
-      return false;
-      break;
-    case RAISE:
-      if (record->event.pressed) {
-        layer_on(_RAISE);
-        update_tri_layer(_LOWER, _RAISE, _ADJUST);
-      } else {
-        layer_off(_RAISE);
-        update_tri_layer(_LOWER, _RAISE, _ADJUST);
-      }
-      return false;
-      break;
     case BACKLIT:
       if (record->event.pressed) {
         register_code(KC_RSFT);
diff --git a/quantum/quantum.c b/quantum/quantum.c
index 5a2a73d4a..2662e5ef1 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -780,12 +780,14 @@ void set_single_persistent_default_layer(uint8_t default_layer) {
   default_layer_set(1U<<default_layer);
 }
 
+uint32_t update_tri_layer_state(uint32_t state, uint8_t layer1, uint8_t layer2, uint8_t layer3) {
+  uint32_t mask12 = (1UL << layer1) | (1UL << layer2);
+  uint32_t mask3 = 1UL << layer3;
+  return (state & mask12) == mask12 ? (state | mask3) : (state & ~mask3);
+}
+
 void update_tri_layer(uint8_t layer1, uint8_t layer2, uint8_t layer3) {
-  if (IS_LAYER_ON(layer1) && IS_LAYER_ON(layer2)) {
-    layer_on(layer3);
-  } else {
-    layer_off(layer3);
-  }
+  layer_state_set(update_tri_layer_state(layer_state, layer1, layer2, layer3));
 }
 
 void tap_random_base64(void) {
diff --git a/quantum/quantum.h b/quantum/quantum.h
index 80a606f09..195f578de 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -142,6 +142,7 @@ void send_char(char ascii_code);
 
 // For tri-layer
 void update_tri_layer(uint8_t layer1, uint8_t layer2, uint8_t layer3);
+uint32_t update_tri_layer_state(uint32_t state, uint8_t layer1, uint8_t layer2, uint8_t layer3);
 
 void set_single_persistent_default_layer(uint8_t default_layer);
 
-- 
2.39.2