initial implementation for modifiers

https://github.com/zmkfirmware/zmk/issues/86

4 files changed, 58 insertions, 49 deletions

diff --git a/app/src/behaviors/behavior_hold_tap.c b/app/src/behaviors/behavior_hold_tap.c
index 8b3620e..ac91e7d 100644
--- a/app/src/behaviors/behavior_hold_tap.c
+++ b/app/src/behaviors/behavior_hold_tap.c
@@ -8,6 +8,7 @@
 
 #include <device.h>
 #include <drivers/behavior.h>
+#include <dt-bindings/zmk/keys.h>
 #include <logging/log.h>
 #include <zmk/behavior.h>
 #include <zmk/matrix.h>
@@ -16,7 +17,6 @@
 #include <zmk/events/position-state-changed.h>
 #include <zmk/events/keycode-state-changed.h>
 #include <zmk/events/modifiers-state-changed.h>
-#include <zmk/hid.h>
 #include <zmk/behavior.h>
 
 LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
@@ -427,7 +427,7 @@ static int position_state_changed_listener(const struct zmk_event_header *eh) {
     return ZMK_EV_EVENT_CAPTURED;
 }
 
-static bool is_mod(struct keycode_state_changed *ev) {
+static inline bool only_mods(struct keycode_state_changed *ev) {
     return ev->usage_page == USAGE_KEYPAD && ev->keycode >= LCTL && ev->keycode <= RGUI;
 }
 
@@ -440,7 +440,7 @@ static int keycode_state_changed_listener(const struct zmk_event_header *eh) {
         return 0;
     }
 
-    if (!is_mod(ev)) {
+    if (!only_mods(ev)) {
         // LOG_DBG("0x%02X bubble (not a mod)", ev->keycode);
         return 0;
     }
diff --git a/app/src/hid.c b/app/src/hid.c
index 216cec7..001d7d3 100644
--- a/app/src/hid.c
+++ b/app/src/hid.c
@@ -8,29 +8,44 @@
 LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 
 #include <zmk/hid.h>
+#include <dt-bindings/zmk/keys.h>
 
 static struct zmk_hid_keypad_report kp_report = {
     .report_id = 1, .body = {.modifiers = 0, ._reserved = 0, .keys = {0}}};
 
 static struct zmk_hid_consumer_report consumer_report = {.report_id = 2, .body = {.keys = {0}}};
 
-#define _TOGGLE_MOD(mod, state)                                                                    \
-    if (modifier > MOD_RGUI) {                                                                     \
-        return -EINVAL;                                                                            \
-    }                                                                                              \
-    WRITE_BIT(kp_report.body.modifiers, mod, state);                                               \
-    return 0;
+// Keep track of how often a modifier was pressed.
+// Only release the modifier if the count is 0.
+static int explicit_modifier_counts[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+static zmk_mod_flags explicit_modifiers = 0;
 
-int zmk_hid_register_mod(zmk_mod modifier) { _TOGGLE_MOD(modifier, true); }
-int zmk_hid_unregister_mod(zmk_mod modifier) { _TOGGLE_MOD(modifier, false); }
+#define SET_MODIFIERS(mods)                                                                        \
+    {                                                                                              \
+        kp_report.body.modifiers = mods;                                                           \
+        LOG_DBG("Modifiers set to 0x%02X", kp_report.body.modifiers);                              \
+    }
 
-int zmk_hid_register_mods(zmk_mod_flags modifiers) {
-    kp_report.body.modifiers |= modifiers;
+int zmk_hid_register_mod(zmk_mod modifier) {
+    explicit_modifier_counts[modifier]++;
+    LOG_DBG("Modifier %d count %d", modifier, explicit_modifier_counts[modifier]);
+    WRITE_BIT(explicit_modifiers, modifier, true);
+    SET_MODIFIERS(explicit_modifiers);
     return 0;
 }
 
-int zmk_hid_unregister_mods(zmk_mod_flags modifiers) {
-    kp_report.body.modifiers &= ~modifiers;
+int zmk_hid_unregister_mod(zmk_mod modifier) {
+    if (explicit_modifier_counts[modifier] <= 0) {
+        LOG_ERR("Tried to unregister modifier %d too often", modifier);
+        return -EINVAL;
+    }
+    explicit_modifier_counts[modifier]--;
+    LOG_DBG("Modifier %d count: %d", modifier, explicit_modifier_counts[modifier]);
+    if (explicit_modifier_counts[modifier] == 0) {
+        LOG_DBG("Modifier %d released", modifier);
+        WRITE_BIT(explicit_modifiers, modifier, false);
+    }
+    SET_MODIFIERS(explicit_modifiers);
     return 0;
 }
 
@@ -52,6 +67,16 @@ int zmk_hid_unregister_mods(zmk_mod_flags modifiers) {
         break;                                                                                     \
     }
 
+int zmk_hid_implicit_modifiers_press(zmk_mod_flags implicit_modifiers) {
+    SET_MODIFIERS(explicit_modifiers | implicit_modifiers);
+    return 0;
+}
+
+int zmk_hid_implicit_modifiers_release() {
+    SET_MODIFIERS(explicit_modifiers);
+    return 0;
+}
+
 int zmk_hid_keypad_press(zmk_key code) {
     if (code >= LCTL && code <= RGUI) {
         return zmk_hid_register_mod(code - LCTL);
diff --git a/app/src/hid_listener.c b/app/src/hid_listener.c
index 4467e6d..32e9d97 100644
--- a/app/src/hid_listener.c
+++ b/app/src/hid_listener.c
@@ -15,10 +15,11 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 #include <zmk/hid.h>
 #include <zmk/endpoints.h>
 
-static int hid_listener_keycode_pressed(u8_t usage_page, u32_t keycode) {
+static int hid_listener_keycode_pressed(u8_t usage_page, u32_t keycode,
+                                        zmk_mod_flags implicit_modifiers) {
     int err;
-    LOG_DBG("usage_page 0x%02X keycode 0x%02X", usage_page, keycode);
-
+    LOG_DBG("usage_page 0x%02X keycode 0x%02X mods 0x%02X", usage_page, keycode,
+            implicit_modifiers);
     switch (usage_page) {
     case USAGE_KEYPAD:
         err = zmk_hid_keypad_press(keycode);
@@ -35,14 +36,15 @@ static int hid_listener_keycode_pressed(u8_t usage_page, u32_t keycode) {
         }
         break;
     }
-
+    zmk_hid_implicit_modifiers_press(implicit_modifiers);
     return zmk_endpoints_send_report(usage_page);
 }
 
-static int hid_listener_keycode_released(u8_t usage_page, u32_t keycode) {
+static int hid_listener_keycode_released(u8_t usage_page, u32_t keycode,
+                                         zmk_mod_flags implicit_modifiers) {
     int err;
-    LOG_DBG("usage_page 0x%02X keycode 0x%02X", usage_page, keycode);
-
+    LOG_DBG("usage_page 0x%02X keycode 0x%02X mods 0x%02X", usage_page, keycode,
+            implicit_modifiers);
     switch (usage_page) {
     case USAGE_KEYPAD:
         err = zmk_hid_keypad_release(keycode);
@@ -57,44 +59,27 @@ static int hid_listener_keycode_released(u8_t usage_page, u32_t keycode) {
             LOG_ERR("Unable to release keycode");
             return err;
         }
-        break;
     }
+    // There is a minor issue with this code.
+    // If LC(A) is pressed, then LS(B), then LC(A) is released, the shift for B will be released
+    // prematurely. This causes if LS(B) to repeat like Bbbbbbbb when pressed for a long time.
+    // Solving this would require keeping track of which key's implicit modifiers are currently
+    // active and only releasing modifiers at that time.
+    zmk_hid_implicit_modifiers_release();
     return zmk_endpoints_send_report(usage_page);
 }
 
-static int hid_listener_modifiers_pressed(zmk_mod_flags modifiers) {
-    LOG_DBG("modifiers %d", modifiers);
-
-    zmk_hid_register_mods(modifiers);
-    return zmk_endpoints_send_report(USAGE_KEYPAD);
-}
-
-static int hid_listener_modifiers_released(zmk_mod_flags modifiers) {
-    LOG_DBG("modifiers %d", modifiers);
-
-    zmk_hid_unregister_mods(modifiers);
-    return zmk_endpoints_send_report(USAGE_KEYPAD);
-}
-
 int hid_listener(const struct zmk_event_header *eh) {
     if (is_keycode_state_changed(eh)) {
         const struct keycode_state_changed *ev = cast_keycode_state_changed(eh);
         if (ev->state) {
-            hid_listener_keycode_pressed(ev->usage_page, ev->keycode);
-        } else {
-            hid_listener_keycode_released(ev->usage_page, ev->keycode);
-        }
-    } else if (is_modifiers_state_changed(eh)) {
-        const struct modifiers_state_changed *ev = cast_modifiers_state_changed(eh);
-        if (ev->state) {
-            hid_listener_modifiers_pressed(ev->modifiers);
+            hid_listener_keycode_pressed(ev->usage_page, ev->keycode, ev->implicit_modifiers);
         } else {
-            hid_listener_modifiers_released(ev->modifiers);
+            hid_listener_keycode_released(ev->usage_page, ev->keycode, ev->implicit_modifiers);
         }
     }
     return 0;
 }
 
 ZMK_LISTENER(hid_listener, hid_listener);
-ZMK_SUBSCRIPTION(hid_listener, keycode_state_changed);
-ZMK_SUBSCRIPTION(hid_listener, modifiers_state_changed);
\ No newline at end of file
+ZMK_SUBSCRIPTION(hid_listener, keycode_state_changed);
\ No newline at end of file
diff --git a/app/src/keymap.c b/app/src/keymap.c
index 74fe60d..1d289e5 100644
--- a/app/src/keymap.c
+++ b/app/src/keymap.c
@@ -11,7 +11,6 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 #include <zmk/matrix.h>
 #include <zmk/sensors.h>
 #include <zmk/keymap.h>
-#include <dt-bindings/zmk/matrix-transform.h>
 #include <drivers/behavior.h>
 #include <zmk/behavior.h>