3 files changed, 127 insertions, 1 deletions

diff --git a/tmk_core/common/action.c b/tmk_core/common/action.c
index be6dea2b7..08ef22eb9 100644
--- a/tmk_core/common/action.c
+++ b/tmk_core/common/action.c
@@ -41,6 +41,12 @@ void action_exec(keyevent_t event)
         dprint("EVENT: "); debug_event(event); dprintln();
     }
 
+#ifdef ONEHAND_ENABLE
+    if (!IS_NOEVENT(event)) {
+        process_hand_swap(&event);
+    }
+#endif
+
     keyrecord_t record = { .event = event };
 
 #ifndef NO_ACTION_TAPPING
@@ -53,6 +59,26 @@ void action_exec(keyevent_t event)
 #endif
 }
 
+#ifdef ONEHAND_ENABLE
+bool swap_hands = false;
+
+void process_hand_swap(keyevent_t *event) {
+    static swap_state_row_t swap_state[MATRIX_ROWS];
+
+    keypos_t pos = event->key;
+    swap_state_row_t col_bit = (swap_state_row_t)1<<pos.col;
+    bool do_swap = event->pressed ? swap_hands :
+                                    swap_state[pos.row] & (col_bit);
+
+    if (do_swap) {
+        event->key = hand_swap_config[pos.row][pos.col];
+        swap_state[pos.row] |= col_bit;
+    } else {
+        swap_state[pos.row] &= ~(col_bit);
+    }
+}
+#endif
+
 #if !defined(NO_ACTION_LAYER) && defined(PREVENT_STUCK_MODIFIERS)
 bool disable_action_cache = false;
 
@@ -440,6 +466,54 @@ void process_action(keyrecord_t *record, action_t action)
 #endif
         case ACT_COMMAND:
             break;
+#ifdef ONEHAND_ENABLE
+        case ACT_SWAP_HANDS:
+            switch (action.swap.code) {
+                case OP_SH_TOGGLE:
+                    if (event.pressed) {
+                        swap_hands = !swap_hands;
+                    }
+                    break;
+                case OP_SH_ON_OFF:
+                    swap_hands = event.pressed;
+                    break;
+                case OP_SH_OFF_ON:
+                    swap_hands = !event.pressed;
+                    break;
+                case OP_SH_ON:
+                    if (!event.pressed) {
+                        swap_hands = true;
+                    }
+                    break;
+                case OP_SH_OFF:
+                    if (!event.pressed) {
+                        swap_hands = false;
+                    }
+                    break;
+    #ifndef NO_ACTION_TAPPING
+                case OP_SH_TAP_TOGGLE:
+                    /* tap toggle */
+                    if (tap_count > 0) {
+                        if (!event.pressed) {
+                            swap_hands = !swap_hands;
+                        }
+                    } else {
+                        swap_hands = event.pressed;
+                    }
+                    break;
+                default:
+                    if (tap_count > 0) {
+                        if (event.pressed) {
+                            register_code(action.swap.code);
+                        } else {
+                            unregister_code(action.swap.code);
+                        }
+                    } else {
+                        swap_hands = event.pressed;
+                    }
+    #endif
+            }
+#endif
 #ifndef NO_ACTION_FUNCTION
         case ACT_FUNCTION:
             action_function(record, action.func.id, action.func.opt);
@@ -652,6 +726,13 @@ bool is_tap_key(keypos_t key)
                     return true;
             }
             return false;
+        case ACT_SWAP_HANDS:
+            switch (action.swap.code) {
+                case 0x00 ... 0xdf:
+                case OP_SH_TAP_TOGGLE:
+                    return true;
+            }
+            return false;
         case ACT_MACRO:
         case ACT_FUNCTION:
             if (action.func.opt & FUNC_TAP) { return true; }
@@ -692,6 +773,7 @@ void debug_action(action_t action)
         case ACT_MACRO:             dprint("ACT_MACRO");             break;
         case ACT_COMMAND:           dprint("ACT_COMMAND");           break;
         case ACT_FUNCTION:          dprint("ACT_FUNCTION");          break;
+        case ACT_SWAP_HANDS:        dprint("ACT_SWAP_HANDS");        break;
         default:                    dprint("UNKNOWN");               break;
     }
     dprintf("[%X:%02X]", action.kind.param>>8, action.kind.param&0xff);
diff --git a/tmk_core/common/action.h b/tmk_core/common/action.h
index e8aa12a7c..b9bdfe642 100644
--- a/tmk_core/common/action.h
+++ b/tmk_core/common/action.h
@@ -65,6 +65,24 @@ bool process_record_quantum(keyrecord_t *record);
 #if !defined(NO_ACTION_LAYER) && defined(PREVENT_STUCK_MODIFIERS)
 extern bool disable_action_cache;
 #endif
+
+/* Code for handling one-handed key modifiers. */
+#ifdef ONEHAND_ENABLE
+extern bool swap_hands;
+extern const keypos_t hand_swap_config[MATRIX_ROWS][MATRIX_COLS];
+#if (MATRIX_COLS <= 8)
+typedef  uint8_t    swap_state_row_t;
+#elif (MATRIX_COLS <= 16)
+typedef  uint16_t   swap_state_row_t;
+#elif (MATRIX_COLS <= 32)
+typedef  uint32_t   swap_state_row_t;
+#else
+#error "MATRIX_COLS: invalid value"
+#endif
+
+void process_hand_swap(keyevent_t *record);
+#endif
+
 void process_record_nocache(keyrecord_t *record);
 void process_record(keyrecord_t *record);
 void process_action(keyrecord_t *record, action_t action);
diff --git a/tmk_core/common/action_code.h b/tmk_core/common/action_code.h
index ca729aaec..33da35f35 100644
--- a/tmk_core/common/action_code.h
+++ b/tmk_core/common/action_code.h
@@ -108,6 +108,8 @@ enum action_kind_id {
     /* Other Keys */
     ACT_USAGE           = 0b0100,
     ACT_MOUSEKEY        = 0b0101,
+    /* One-hand Support */
+    ACT_SWAP_HANDS      = 0b0110,
     /* Layer Actions */
     ACT_LAYER           = 0b1000,
     ACT_LAYER_TAP       = 0b1010, /* Layer  0-15 */
@@ -178,6 +180,11 @@ typedef union {
         uint8_t  opt    :4;
         uint8_t  kind   :4;
     } func;
+    struct action_swap {
+        uint8_t  code   :8;
+        uint8_t  opt   :4;
+        uint8_t  kind   :4;
+    } swap;
 } action_t;
 
 
@@ -295,6 +302,7 @@ enum backlight_opt {
     BACKLIGHT_STEP     = 3,
     BACKLIGHT_LEVEL    = 4,
 };
+
 /* Macro */
 #define ACTION_MACRO(id)                ACTION(ACT_MACRO, (id))
 #define ACTION_MACRO_TAP(id)            ACTION(ACT_MACRO, FUNC_TAP<<8 | (id))
@@ -306,7 +314,7 @@ enum backlight_opt {
 #define ACTION_BACKLIGHT_STEP()         ACTION(ACT_BACKLIGHT, BACKLIGHT_STEP << 8)
 #define ACTION_BACKLIGHT_LEVEL(level)   ACTION(ACT_BACKLIGHT, BACKLIGHT_LEVEL << 8 | (level))
 /* Command */
-#define ACTION_COMMAND(id, opt)         ACTION(ACT_COMMAND,  (opt)<<8 | (addr))
+#define ACTION_COMMAND(id, opt)         ACTION(ACT_COMMAND,  (opt)<<8 | (id))
 /* Function */
 enum function_opts {
     FUNC_TAP = 0x8,     /* indciates function is tappable */
@@ -314,5 +322,23 @@ enum function_opts {
 #define ACTION_FUNCTION(id)             ACTION(ACT_FUNCTION, (id))
 #define ACTION_FUNCTION_TAP(id)         ACTION(ACT_FUNCTION, FUNC_TAP<<8 | (id))
 #define ACTION_FUNCTION_OPT(id, opt)    ACTION(ACT_FUNCTION, (opt)<<8 | (id))
+/* OneHand Support */
+enum swap_hands_pram_tap_op {
+    OP_SH_TOGGLE = 0xF0,
+    OP_SH_TAP_TOGGLE,
+    OP_SH_ON_OFF,
+    OP_SH_OFF_ON,
+    OP_SH_OFF,
+    OP_SH_ON,
+};
+
+#define ACTION_SWAP_HANDS()             ACTION_SWAP_HANDS_ON_OFF()
+#define ACTION_SWAP_HANDS_TOGGLE()      ACTION(ACT_SWAP_HANDS, OP_SH_TOGGLE)
+#define ACTION_SWAP_HANDS_TAP_TOGGLE()  ACTION(ACT_SWAP_HANDS, OP_SH_TAP_TOGGLE)
+#define ACTION_SWAP_HANDS_TAP_KEY(key)  ACTION(ACT_SWAP_HANDS, key)
+#define ACTION_SWAP_HANDS_ON_OFF()      ACTION(ACT_SWAP_HANDS, OP_SH_ON_OFF)
+#define ACTION_SWAP_HANDS_OFF_ON()      ACTION(ACT_SWAP_HANDS, OP_SH_OFF_ON)
+#define ACTION_SWAP_HANDS_ON()          ACTION(ACT_SWAP_HANDS, OP_SH_ON)
+#define ACTION_SWAP_HANDS_OFF()         ACTION(ACT_SWAP_HANDS, OP_SH_OFF)
 
 #endif /* ACTION_CODE_H */