From b6bf4e0dce062a535685c4e772f613252d401ed3 Mon Sep 17 00:00:00 2001
From: Ofer Plesser <plesserofer@gmail.com>
Date: Sat, 10 Dec 2016 16:11:59 +0200
Subject: [PATCH] Added support for timing out combos if a key as been pressed
 for longer than COMBO_TERM

---
 quantum/process_keycode/process_combo.c | 107 +++++++++++++++++-------
 quantum/process_keycode/process_combo.h |  20 ++++-
 quantum/quantum.c                       |   5 ++
 3 files changed, 101 insertions(+), 31 deletions(-)

diff --git a/quantum/process_keycode/process_combo.c b/quantum/process_keycode/process_combo.c
index a6cfed11a..ff7e8aba5 100644
--- a/quantum/process_keycode/process_combo.c
+++ b/quantum/process_keycode/process_combo.c
@@ -1,11 +1,6 @@
 #include "process_combo.h"
 #include "print.h"
 
-// __attribute__ ((weak))
-// combo_t key_combos[] = {
-
-// };
-
 #define SEND_KEY(key) \
 do { \
     register_code16(key); \
@@ -13,54 +8,110 @@ do { \
     unregister_code16(key); \
 } while(0)
 
+#define COMBO_TIMER_ELAPSED -1
+
+#if COMBO_TERM
+#define IS_COMBO_KEY_HELD(combo)            (COMBO_TIMER_ELAPSED == combo->timer ? false : true)
+#define RESET_COMBO_TIMER_AND_KEY(combo)    combo->timer = 0; combo->key = 0
+#else
+#define IS_COMBO_KEY_HELD(combo)            (true)
+#define RESET_COMBO_TIMER_AND_KEY(combo)    do {} while (0)
+#endif
+
+
+__attribute__ ((weak))
+combo_t key_combos[COMBO_COUNT] = {
+
+};
+
+static inline void reset_combo(combo_t *combo)
+{
+    combo->state = 0;
+    RESET_COMBO_TIMER_AND_KEY(combo);
+}
 
 #define ALL_COMBO_KEYS_ARE_DOWN (((1<<count)-1) == combo->state)
+#define NO_COMBO_KEYS_ARE_DOWN  (0 == combo->state)
+#define KEY_STATE_DOWN(key)     do{ combo->state |= (1<<key); } while(0)
+#define KEY_STATE_UP(key)       do{ combo->state &= ~(1<<key); } while(0)
 static bool process_single_combo(combo_t *combo, uint16_t keycode, keyrecord_t *record) 
 {
     uint8_t count = 0;
-    bool is_combo_key = false;
-    // bool combo_key_released = false;
+    uint8_t index = -1;
+    /* Find index of keycode and number of combo keys */
+    for (const uint16_t *keys = combo->keys; ;++count) {
+        uint16_t key = pgm_read_word(&keys[count]);
+        if (keycode == key) index = count;
+        if (COMBO_END == key) break;
+    }
 
-    // Count the number of combo keys
-    for (const uint16_t *key = combo->keys; COMBO_END != pgm_read_word(key); ++key, ++count);
+    /* Return if not a combo key */
+    if (-1 == index) return false;
 
-    for (uint8_t i = 0; i < count; ++i) {
-        uint16_t key = pgm_read_word(&combo->keys[i]);
+    bool is_combo_active = IS_COMBO_KEY_HELD(combo);
 
-        if (key == keycode) {
-            is_combo_key = true;
+    if (record->event.pressed) {
+        KEY_STATE_DOWN(index);
+        
+#if COMBO_TERM
+        if (is_combo_active) {
+            combo->timer = timer_read();
+            combo->key = keycode;
+        }
+#endif
 
-            if (record->event.pressed) {
-                combo->state |= (1<<i);
-            } else { // Combo key released
-                if (!combo->state) {
-                    // The combo was sent, no need to send released key
-                    return true;
-                }
+    } else {
+        if (is_combo_active && combo->state) { /* Combo key was tapped */
+            RESET_COMBO_TIMER_AND_KEY(combo);            
+            SEND_KEY(keycode);
+        }
 
-                combo->state &= ~(1<<i);
-                SEND_KEY(key);
-            }
+#if COMBO_TERM
+        if (!is_combo_active && keycode == combo->key) { /* Held combo key was released */
+            unregister_code16(combo->key);
         }
+#endif
+
+        KEY_STATE_UP(index);
     }
 
-    if (ALL_COMBO_KEYS_ARE_DOWN) {
+    if (ALL_COMBO_KEYS_ARE_DOWN && is_combo_active) {
         SEND_KEY(combo->action);
-        combo->state = 0;    
+        reset_combo(combo);
+    } 
+    
+    if(NO_COMBO_KEYS_ARE_DOWN && !is_combo_active) {
+        reset_combo(combo);
     }
 
-    return is_combo_key;
+    return is_combo_active;
 }
 
-
 bool process_combo(uint16_t keycode, keyrecord_t *record)
 {
     bool is_combo_key = false;
 
-    for (int i = 0; i < NUM_ELEMS(key_combos); ++i) {
+    for (int i = 0; i < COMBO_COUNT; ++i) {
         combo_t *combo = &key_combos[i];
         is_combo_key |= process_single_combo(combo, keycode, record);
     }    
 
     return !is_combo_key;
+}
+
+void matrix_scan_combo(void)
+{
+#if COMBO_TERM
+    for (int i = 0; i < COMBO_COUNT; ++i) {
+        combo_t *combo = &key_combos[i];
+        if (combo->timer && 
+            combo->timer != COMBO_TIMER_ELAPSED && 
+            timer_elapsed(combo->timer) > COMBO_TERM) {
+
+            combo->timer = COMBO_TIMER_ELAPSED;
+            unregister_code16(combo->key);
+            register_code16(combo->key);
+        }
+    }
+#endif
 }
\ No newline at end of file
diff --git a/quantum/process_keycode/process_combo.h b/quantum/process_keycode/process_combo.h
index 68786c0f1..c475acd33 100644
--- a/quantum/process_keycode/process_combo.h
+++ b/quantum/process_keycode/process_combo.h
@@ -5,21 +5,35 @@
 #include "progmem.h"
 #include "quantum.h"
 
+#ifndef COMBO_TERM
+#define COMBO_TERM TAPPING_TERM
+#endif
 
 typedef struct
 {
     const uint16_t *keys;
     uint16_t action;        
     uint32_t state;
+#if COMBO_TERM
+    uint16_t timer;
+    uint16_t key;
+#endif
 } combo_t;
 
 
+#if COMBO_TERM
+#define COMBO(ck, ca) {.keys = &(ck)[0], .action = (ca), .state = 0, .timer = 0, .key = 0}
+#else
+#define COMBO(ck, ca) {.keys = &(ck)[0], .action = (ca), .state = 0 }
+#endif
 #define COMBO_END 0
-#define NUM_ELEMS(a) (sizeof(a)/sizeof 0[a])
+#ifndef COMBO_COUNT
+#define COMBO_COUNT 0
+#endif
 
-
-extern combo_t key_combos[1];
+extern combo_t key_combos[COMBO_COUNT];
 
 bool process_combo(uint16_t keycode, keyrecord_t *record);
+void matrix_scan_combo(void);
 
 #endif
\ No newline at end of file
diff --git a/quantum/quantum.c b/quantum/quantum.c
index eabeacff8..7767b6301 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -509,6 +509,11 @@ void matrix_scan_quantum() {
   #ifdef TAP_DANCE_ENABLE
     matrix_scan_tap_dance();
   #endif
+
+  #ifdef COMBO_ENABLE
+    matrix_scan_combo();
+  #endif
+
   matrix_scan_kb();
 }
 
-- 
2.39.2