Refactor Leader key feature (#19632)

Co-authored-by: Drashna Jaelre <drashna@live.com>

6 files changed, 248 insertions, 81 deletions

diff --git a/quantum/keyboard.c b/quantum/keyboard.c
index 1de5f1cd0c..e8e3292dbc 100644
--- a/quantum/keyboard.c
+++ b/quantum/keyboard.c
@@ -105,6 +105,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifdef CAPS_WORD_ENABLE
 #    include "caps_word.h"
 #endif
+#ifdef LEADER_ENABLE
+#    include "leader.h"
+#endif
 
 static uint32_t last_input_modification_time = 0;
 uint32_t        last_input_activity_time(void) {
@@ -546,6 +549,10 @@ void quantum_task(void) {
     combo_task();
 #endif
 
+#ifdef LEADER_ENABLE
+    leader_task();
+#endif
+
 #ifdef WPM_ENABLE
     decay_wpm();
 #endif
diff --git a/quantum/leader.c b/quantum/leader.c
new file mode 100644
index 0000000000..272609ad0c
--- /dev/null
+++ b/quantum/leader.c
@@ -0,0 +1,101 @@
+// Copyright 2023 QMK
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "leader.h"
+#include "timer.h"
+#include "util.h"
+
+#include <string.h>
+
+#ifndef LEADER_TIMEOUT
+#    define LEADER_TIMEOUT 300
+#endif
+
+// Leader key stuff
+bool     leading              = false;
+uint16_t leader_time          = 0;
+uint16_t leader_sequence[5]   = {0, 0, 0, 0, 0};
+uint8_t  leader_sequence_size = 0;
+
+__attribute__((weak)) void leader_start_user(void) {}
+
+__attribute__((weak)) void leader_end_user(void) {}
+
+void leader_start(void) {
+    if (leading) {
+        return;
+    }
+    leader_start_user();
+    leading              = true;
+    leader_time          = timer_read();
+    leader_sequence_size = 0;
+    memset(leader_sequence, 0, sizeof(leader_sequence));
+}
+
+void leader_end(void) {
+    leading = false;
+    leader_end_user();
+}
+
+void leader_task(void) {
+    if (leader_sequence_active() && leader_sequence_timed_out()) {
+        leader_end();
+    }
+}
+
+bool leader_sequence_active(void) {
+    return leading;
+}
+
+bool leader_sequence_add(uint16_t keycode) {
+    if (leader_sequence_size >= ARRAY_SIZE(leader_sequence)) {
+        return false;
+    }
+
+#if defined(LEADER_NO_TIMEOUT)
+    if (leader_sequence_size == 0) {
+        leader_reset_timer();
+    }
+#endif
+
+    leader_sequence[leader_sequence_size] = keycode;
+    leader_sequence_size++;
+
+    return true;
+}
+
+bool leader_sequence_timed_out(void) {
+#if defined(LEADER_NO_TIMEOUT)
+    return leader_sequence_size > 0 && timer_elapsed(leader_time) > LEADER_TIMEOUT;
+#else
+    return timer_elapsed(leader_time) > LEADER_TIMEOUT;
+#endif
+}
+
+void leader_reset_timer(void) {
+    leader_time = timer_read();
+}
+
+bool leader_sequence_is(uint16_t kc1, uint16_t kc2, uint16_t kc3, uint16_t kc4, uint16_t kc5) {
+    return leader_sequence[0] == kc1 && leader_sequence[1] == kc2 && leader_sequence[2] == kc3 && leader_sequence[3] == kc4 && leader_sequence[4] == kc5;
+}
+
+bool leader_sequence_one_key(uint16_t kc) {
+    return leader_sequence_is(kc, 0, 0, 0, 0);
+}
+
+bool leader_sequence_two_keys(uint16_t kc1, uint16_t kc2) {
+    return leader_sequence_is(kc1, kc2, 0, 0, 0);
+}
+
+bool leader_sequence_three_keys(uint16_t kc1, uint16_t kc2, uint16_t kc3) {
+    return leader_sequence_is(kc1, kc2, kc3, 0, 0);
+}
+
+bool leader_sequence_four_keys(uint16_t kc1, uint16_t kc2, uint16_t kc3, uint16_t kc4) {
+    return leader_sequence_is(kc1, kc2, kc3, kc4, 0);
+}
+
+bool leader_sequence_five_keys(uint16_t kc1, uint16_t kc2, uint16_t kc3, uint16_t kc4, uint16_t kc5) {
+    return leader_sequence_is(kc1, kc2, kc3, kc4, kc5);
+}
diff --git a/quantum/leader.h b/quantum/leader.h
new file mode 100644
index 0000000000..1999006c56
--- /dev/null
+++ b/quantum/leader.h
@@ -0,0 +1,119 @@
+// Copyright 2023 QMK
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <stdbool.h>
+#include <stdint.h>
+
+/**
+ * \defgroup leader
+ *
+ * Leader Key
+ * \{
+ */
+
+/**
+ * \brief User callback, invoked when the leader sequence begins.
+ */
+void leader_start_user(void);
+
+/**
+ * \brief User callback, invoked when the leader sequence ends.
+ */
+void leader_end_user(void);
+
+/**
+ * Begin the leader sequence, resetting the buffer and timer.
+ */
+void leader_start(void);
+
+/**
+ * End the leader sequence.
+ */
+void leader_end(void);
+
+void leader_task(void);
+
+/**
+ * Whether the leader sequence is active.
+ */
+bool leader_sequence_active(void);
+
+/**
+ * Add the given keycode to the sequence buffer.
+ *
+ * If `LEADER_NO_TIMEOUT` is defined, the timer is reset if the buffer is empty.
+ *
+ * \param keycode The keycode to add.
+ *
+ * \return `true` if the keycode was added, `false` if the buffer is full.
+ */
+bool leader_sequence_add(uint16_t keycode);
+
+/**
+ * Whether the leader sequence has reached the timeout.
+ *
+ * If `LEADER_NO_TIMEOUT` is defined, the buffer must also contain at least one key.
+ */
+bool leader_sequence_timed_out(void);
+
+/**
+ * Reset the leader sequence timer.
+ */
+void leader_reset_timer(void);
+
+/**
+ * Check the sequence buffer for the given keycode.
+ *
+ * \param kc The keycode to check.
+ *
+ * \return `true` if the sequence buffer matches.
+ */
+bool leader_sequence_one_key(uint16_t kc);
+
+/**
+ * Check the sequence buffer for the given keycodes.
+ *
+ * \param kc1 The first keycode to check.
+ * \param kc2 The second keycode to check.
+ *
+ * \return `true` if the sequence buffer matches.
+ */
+bool leader_sequence_two_keys(uint16_t kc1, uint16_t kc2);
+
+/**
+ * Check the sequence buffer for the given keycodes.
+ *
+ * \param kc1 The first keycode to check.
+ * \param kc2 The second keycode to check.
+ * \param kc3 The third keycode to check.
+ *
+ * \return `true` if the sequence buffer matches.
+ */
+bool leader_sequence_three_keys(uint16_t kc1, uint16_t kc2, uint16_t kc3);
+
+/**
+ * Check the sequence buffer for the given keycodes.
+ *
+ * \param kc1 The first keycode to check.
+ * \param kc2 The second keycode to check.
+ * \param kc3 The third keycode to check.
+ * \param kc4 The fourth keycode to check.
+ *
+ * \return `true` if the sequence buffer matches.
+ */
+bool leader_sequence_four_keys(uint16_t kc1, uint16_t kc2, uint16_t kc3, uint16_t kc4);
+
+/**
+ * Check the sequence buffer for the given keycodes.
+ *
+ * \param kc1 The first keycode to check.
+ * \param kc2 The second keycode to check.
+ * \param kc3 The third keycode to check.
+ * \param kc4 The fourth keycode to check.
+ * \param kc5 The fifth keycode to check.
+ *
+ * \return `true` if the sequence buffer matches.
+ */
+bool leader_sequence_five_keys(uint16_t kc1, uint16_t kc2, uint16_t kc3, uint16_t kc4, uint16_t kc5);
+
+/** \} */
diff --git a/quantum/process_keycode/process_leader.c b/quantum/process_keycode/process_leader.c
index 80bc96e65f..a9823b6285 100644
--- a/quantum/process_keycode/process_leader.c
+++ b/quantum/process_keycode/process_leader.c
@@ -15,71 +15,34 @@
  */
 
 #include "process_leader.h"
-#include <string.h>
+#include "leader.h"
 
-#ifndef LEADER_TIMEOUT
-#    define LEADER_TIMEOUT 300
+bool process_leader(uint16_t keycode, keyrecord_t *record) {
+    if (record->event.pressed) {
+        if (leader_sequence_active() && !leader_sequence_timed_out()) {
+#ifndef LEADER_KEY_STRICT_KEY_PROCESSING
+            if (IS_QK_MOD_TAP(keycode)) {
+                keycode = QK_MOD_TAP_GET_TAP_KEYCODE(keycode);
+            } else if (IS_QK_LAYER_TAP(keycode)) {
+                keycode = QK_LAYER_TAP_GET_TAP_KEYCODE(keycode);
+            }
 #endif
 
-__attribute__((weak)) void leader_start_user(void) {}
-
-__attribute__((weak)) void leader_end_user(void) {}
-
-// Leader key stuff
-bool     leading     = false;
-uint16_t leader_time = 0;
-
-uint16_t leader_sequence[5]   = {0, 0, 0, 0, 0};
-uint8_t  leader_sequence_size = 0;
-
-void leader_start(void) {
-    if (leading) {
-        return;
-    }
-    leader_start_user();
-    leading              = true;
-    leader_time          = timer_read();
-    leader_sequence_size = 0;
-    memset(leader_sequence, 0, sizeof(leader_sequence));
-}
+            if (!leader_sequence_add(keycode)) {
+                leader_end();
 
-void leader_end(void) {
-    leader_end_user();
-}
+                return true;
+            }
 
-bool process_leader(uint16_t keycode, keyrecord_t *record) {
-    // Leader key set-up
-    if (record->event.pressed) {
-        if (leading) {
-#ifndef LEADER_NO_TIMEOUT
-            if (timer_elapsed(leader_time) < LEADER_TIMEOUT)
-#endif // LEADER_NO_TIMEOUT
-            {
-#ifndef LEADER_KEY_STRICT_KEY_PROCESSING
-                if (IS_QK_MOD_TAP(keycode)) {
-                    keycode = QK_MOD_TAP_GET_TAP_KEYCODE(keycode);
-                } else if (IS_QK_LAYER_TAP(keycode)) {
-                    keycode = QK_LAYER_TAP_GET_TAP_KEYCODE(keycode);
-                }
-#endif // LEADER_KEY_STRICT_KEY_PROCESSING
-                if (leader_sequence_size < ARRAY_SIZE(leader_sequence)) {
-                    leader_sequence[leader_sequence_size] = keycode;
-                    leader_sequence_size++;
-                } else {
-                    leading = false;
-                    leader_end_user();
-                    return true;
-                }
 #ifdef LEADER_PER_KEY_TIMING
-                leader_time = timer_read();
+            leader_reset_timer();
 #endif
-                return false;
-            }
-        } else {
-            if (keycode == QK_LEADER) {
-                leader_start();
-            }
+
+            return false;
+        } else if (keycode == QK_LEADER) {
+            leader_start();
         }
     }
+
     return true;
 }
diff --git a/quantum/process_keycode/process_leader.h b/quantum/process_keycode/process_leader.h
index 82b4a3ed7b..eb0f721f60 100644
--- a/quantum/process_keycode/process_leader.h
+++ b/quantum/process_keycode/process_leader.h
@@ -19,27 +19,3 @@
 #include "quantum.h"
 
 bool process_leader(uint16_t keycode, keyrecord_t *record);
-
-void leader_start_user(void);
-void leader_end_user(void);
-
-void leader_start(void);
-void leader_end(void);
-
-#define SEQ_ONE_KEY(key) if (leader_sequence[0] == (key) && leader_sequence[1] == 0 && leader_sequence[2] == 0 && leader_sequence[3] == 0 && leader_sequence[4] == 0)
-#define SEQ_TWO_KEYS(key1, key2) if (leader_sequence[0] == (key1) && leader_sequence[1] == (key2) && leader_sequence[2] == 0 && leader_sequence[3] == 0 && leader_sequence[4] == 0)
-#define SEQ_THREE_KEYS(key1, key2, key3) if (leader_sequence[0] == (key1) && leader_sequence[1] == (key2) && leader_sequence[2] == (key3) && leader_sequence[3] == 0 && leader_sequence[4] == 0)
-#define SEQ_FOUR_KEYS(key1, key2, key3, key4) if (leader_sequence[0] == (key1) && leader_sequence[1] == (key2) && leader_sequence[2] == (key3) && leader_sequence[3] == (key4) && leader_sequence[4] == 0)
-#define SEQ_FIVE_KEYS(key1, key2, key3, key4, key5) if (leader_sequence[0] == (key1) && leader_sequence[1] == (key2) && leader_sequence[2] == (key3) && leader_sequence[3] == (key4) && leader_sequence[4] == (key5))
-
-#define LEADER_EXTERNS()                \
-    extern bool     leading;            \
-    extern uint16_t leader_time;        \
-    extern uint16_t leader_sequence[5]; \
-    extern uint8_t  leader_sequence_size
-
-#ifdef LEADER_NO_TIMEOUT
-#    define LEADER_DICTIONARY() if (leading && leader_sequence_size > 0 && timer_elapsed(leader_time) > LEADER_TIMEOUT)
-#else
-#    define LEADER_DICTIONARY() if (leading && timer_elapsed(leader_time) > LEADER_TIMEOUT)
-#endif
diff --git a/quantum/quantum.h b/quantum/quantum.h
index 708d325a32..315fa25568 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -93,6 +93,7 @@ extern layer_state_t layer_state;
 #endif
 
 #ifdef LEADER_ENABLE
+#    include "leader.h"
 #    include "process_leader.h"
 #endif