Initial stab at mod-tap improvements.

* Not working: Roll over + mod-tap with multiple
  mod-tap bindings!

4 files changed, 179 insertions, 26 deletions

diff --git a/app/src/behaviors/behavior_key_press.c b/app/src/behaviors/behavior_key_press.c
index 34df1c0..7404c79 100644
--- a/app/src/behaviors/behavior_key_press.c
+++ b/app/src/behaviors/behavior_key_press.c
@@ -28,27 +28,17 @@ static int behavior_key_press_init(struct device *dev)
 static int on_keymap_binding_pressed(struct device *dev, u32_t position, u32_t keycode, u32_t _)
 {
   const struct behavior_key_press_config *cfg = dev->config_info;
-  struct keycode_state_changed *ev;
   LOG_DBG("position %d usage_page 0x%02X keycode 0x%02X", position, cfg->usage_page, keycode);
 
-  ev = new_keycode_state_changed();
-  ev->usage_page = cfg->usage_page;
-  ev->keycode = keycode;
-  ev->state = true;
-  return ZMK_EVENT_RAISE(ev);
+  return ZMK_EVENT_RAISE(create_keycode_state_changed(cfg->usage_page, keycode, true));
 }
 
 static int on_keymap_binding_released(struct device *dev, u32_t position, u32_t keycode, u32_t _)
 {
   const struct behavior_key_press_config *cfg = dev->config_info;
-  struct keycode_state_changed *ev;
   LOG_DBG("position %d usage_page 0x%02X keycode 0x%02X", position, cfg->usage_page, keycode);
 
-  ev = new_keycode_state_changed();
-  ev->usage_page = cfg->usage_page;
-  ev->keycode = keycode;
-  ev->state = false;
-  return ZMK_EVENT_RAISE(ev);
+  return ZMK_EVENT_RAISE(create_keycode_state_changed(cfg->usage_page, keycode, false));
 }
 
 static const struct behavior_driver_api behavior_key_press_driver_api = {
diff --git a/app/src/behaviors/behavior_mod_tap.c b/app/src/behaviors/behavior_mod_tap.c
index 62604eb..df3eec2 100644
--- a/app/src/behaviors/behavior_mod_tap.c
+++ b/app/src/behaviors/behavior_mod_tap.c
@@ -10,25 +10,110 @@
 #include <drivers/behavior.h>
 #include <logging/log.h>
 
+#include <zmk/matrix.h>
+#include <zmk/endpoints.h>
 #include <zmk/event-manager.h>
 #include <zmk/events/keycode-state-changed.h>
 #include <zmk/events/modifiers-state-changed.h>
+#include <zmk/hid.h>
 
 LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 
+#define ZMK_BHV_MOD_TAP_MAX_HELD 4
+#define ZMK_BHV_MOD_TAP_MAX_PENDING_KC 4
+
+#define TOGGLE_FIRST(arr, len, match, val) \
+    for (int idx = 0; idx < len; idx++)    \
+    {                                      \
+        if (arr[idx] != match)             \
+        {                                  \
+            continue;                      \
+        }                                  \
+        arr[idx] = val;                    \
+        break;                             \
+    }
+
+struct pending_mod_tap_item {
+  u32_t keycode;
+  u8_t mods;
+};
+
 struct behavior_mod_tap_config { };
 struct behavior_mod_tap_data {
-  u16_t pending_press_positions;
+  struct pending_mod_tap_item pending_mod_taps[ZMK_BHV_MOD_TAP_MAX_HELD];
+  struct pending_mod_tap_item triggered_mod_taps[ZMK_BHV_MOD_TAP_MAX_HELD];
+  struct keycode_state_changed* pending_key_presses[ZMK_BHV_MOD_TAP_MAX_PENDING_KC];
 };
 
+bool have_pending_mods(char *label) {
+  struct device *dev = device_get_binding(label);
+  struct behavior_mod_tap_data *data = dev->driver_data;
+
+  for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_HELD; i++) {
+    if (data->pending_mod_taps[i].mods) {
+      LOG_DBG("Found pending mods for %d and keycode 0x%02X", data->pending_mod_taps[i].mods, data->pending_mod_taps[i].keycode);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool have_pending_keycode(struct behavior_mod_tap_data *data, u32_t keycode)
+{
+  for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_PENDING_KC; i++) {
+    if (data->pending_key_presses[i] == NULL) {
+      continue;
+    }
+
+    if (data->pending_key_presses[i]->keycode == keycode) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+// How to pass context to subscription?!
 int behavior_mod_tap_listener(const struct zmk_event_header *eh)
 {
-  if (is_keycode_state_changed(eh)) {
+  if (is_keycode_state_changed(eh) && have_pending_mods(DT_INST_LABEL(0))) {
     struct device *dev = device_get_binding(DT_INST_LABEL(0));
-    const struct keycode_state_changed *ev = cast_keycode_state_changed(eh);
+    struct keycode_state_changed *ev = cast_keycode_state_changed(eh);
+    struct behavior_mod_tap_data *data = dev->driver_data;
     if (ev->state) {
-      struct behavior_mod_tap_data *data = dev->driver_data;
-      data->pending_press_positions = 0;
+      LOG_DBG("Have pending mods, capturing keycode 0x%02X event to ressend later", ev->keycode);
+      TOGGLE_FIRST(data->pending_key_presses, ZMK_BHV_MOD_TAP_MAX_PENDING_KC, NULL, ev);
+      return ZMK_EV_EVENT_CAPTURED;
+    } else if (have_pending_keycode(data, ev->keycode)) {
+      zmk_mod_flags mods = 0;
+
+      LOG_DBG("Key released, going to activate mods then send pending key presses");
+      for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_HELD; i++) {
+        memcpy(&data->triggered_mod_taps[i], &data->pending_mod_taps[i], sizeof(struct pending_mod_tap_item));
+        data->pending_mod_taps[i].mods = 0;
+        data->pending_mod_taps[i].keycode = 0;
+      }
+      LOG_DBG("After swapping, do I have pending mods? %s", (have_pending_mods(DT_INST_LABEL(0)) ? "true" : "false"));
+
+      for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_HELD; i++) {
+        mods |= data->triggered_mod_taps[i].mods;
+      }
+
+      LOG_DBG("Setting mods: %d", mods);
+
+      zmk_hid_register_mods(mods);
+
+      for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_PENDING_KC; i++) {
+        if (data->pending_key_presses[i] == NULL) {
+          continue;
+        }
+
+        struct keycode_state_changed *ev = data->pending_key_presses[i];
+        data->pending_key_presses[i] = NULL;
+        ZMK_EVENT_RAISE(ev);
+        k_msleep(10);
+      }
     }
   }
   return 0;
@@ -46,22 +131,84 @@ static int behavior_mod_tap_init(struct device *dev)
 static int on_keymap_binding_pressed(struct device *dev, u32_t position, u32_t mods, u32_t keycode)
 {
   struct behavior_mod_tap_data *data = dev->driver_data;
-  LOG_DBG("mods: %d, keycode: %d", mods, keycode);
-  WRITE_BIT(data->pending_press_positions, position, true);
-  return ZMK_EVENT_RAISE(create_modifiers_state_changed(mods, true));
+  LOG_DBG("mods: %d, keycode: 0x%02X", mods, keycode);
+  for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_HELD; i++) {
+    if (data->pending_mod_taps[i].mods != 0) {
+      continue;
+    }
+
+    data->pending_mod_taps[i].mods = mods;
+    data->pending_mod_taps[i].keycode = keycode;
+
+    return 0;
+  }
+
+  return -ENOMEM;
 }
 
 static int on_keymap_binding_released(struct device *dev, u32_t position, u32_t mods, u32_t keycode)
 {
   struct behavior_mod_tap_data *data = dev->driver_data;
+  bool sending_keycode = false;
+  bool sent_pending_key_presses = false;
+  struct keycode_state_changed *pending_key_presses[ZMK_BHV_MOD_TAP_MAX_PENDING_KC];
   LOG_DBG("mods: %d, keycode: %d", mods, keycode);
   
-  ZMK_EVENT_RAISE(create_modifiers_state_changed(mods, false));
-  k_msleep(10); // TODO: Better approach than k_msleep to avoid USB send failures? Retries in the USB endpoint layer?
-  if (data->pending_press_positions & BIT(position)) {
-    ZMK_EVENT_RAISE(create_keycode_state_changed(USAGE_KEYPAD, keycode, true));
+  for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_HELD; i++) {
+    if (data->triggered_mod_taps[i].mods == mods && data->triggered_mod_taps[i].keycode == keycode) {
+      LOG_DBG("Releasing triggered mods: %d", mods);
+      zmk_hid_unregister_mods(mods);
+      data->triggered_mod_taps[i].mods = 0;
+      data->triggered_mod_taps[i].keycode = 0;
+      break;
+    }
+  }
+
+  for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_HELD; i++) {
+    if (data->pending_mod_taps[i].mods == mods && data->pending_mod_taps[i].keycode == keycode) {
+      sending_keycode = true;
+      data->pending_mod_taps[i].mods = 0;
+      data->pending_mod_taps[i].keycode = 0;
+      break;
+    }
+  }
+
+  for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_PENDING_KC; i++) {
+    pending_key_presses[i] = data->pending_key_presses[i];
+    data->pending_key_presses[i] = NULL;
+  }
+
+
+  if (sending_keycode) {
+      struct keycode_state_changed *key_press = create_keycode_state_changed(USAGE_KEYPAD, keycode, true);
+      LOG_DBG("Sending un-triggered mod-tap for keycode: 0x%02X", keycode);
+      ZMK_EVENT_RAISE(key_press);
+      k_msleep(10);
+  }
+  
+
+  for (int i = 0; i < ZMK_BHV_MOD_TAP_MAX_PENDING_KC; i++) {
+    if (pending_key_presses[i] == NULL) {
+      continue;
+    }
+
+    struct keycode_state_changed *ev = pending_key_presses[i];
+    sent_pending_key_presses = true;
+    LOG_DBG("Re-sending latched key press for usage page 0x%02X keycode 0x%02X state %s", ev->usage_page, ev->keycode, (ev->state ? "pressed" : "released"));
+    ZMK_EVENT_RELEASE(ev);
     k_msleep(10);
-    ZMK_EVENT_RAISE(create_keycode_state_changed(USAGE_KEYPAD, keycode, false));
+  }
+
+  if (sending_keycode) {
+      struct keycode_state_changed *key_release = create_keycode_state_changed(USAGE_KEYPAD, keycode, false);
+      LOG_DBG("Sending un-triggered mod-tap release for keycode: 0x%02X", keycode);
+      ZMK_EVENT_RAISE(key_release);
+  }
+
+  if (!sending_keycode && !sent_pending_key_presses) {
+    // Need to ensure the mod release is propagated.
+    zmk_endpoints_send_report(USAGE_KEYPAD);
+
   }
 
   return 0;
diff --git a/app/src/event_manager.c b/app/src/event_manager.c
index 3edba10..5d2e9ed 100644
--- a/app/src/event_manager.c
+++ b/app/src/event_manager.c
@@ -55,6 +55,22 @@ int zmk_event_manager_raise(struct zmk_event_header *event)
     return zmk_event_manager_handle_from(event, 0);
 }
 
+int zmk_event_manager_raise_after(struct zmk_event_header *event, const struct zmk_listener *listener)
+{
+    u8_t len = __event_subscriptions_end - __event_subscriptions_start;
+    for (int i = 0; i < len; i++) {
+        struct zmk_event_subscription *ev_sub = __event_subscriptions_start + i;
+
+        if (ev_sub->event_type == event->event && ev_sub->listener == listener) {
+            return zmk_event_manager_handle_from(event, i+1);
+        }
+    }
+
+    LOG_WRN("Unable to find where to raise this after event");
+
+    return -EINVAL;
+}
+
 int zmk_event_manager_release(struct zmk_event_header *event)
 {
     return zmk_event_manager_handle_from(event, event->last_listener_index + 1);
diff --git a/app/src/events/keycode_state_changed.c b/app/src/events/keycode_state_changed.c
index 964b24a..73508e1 100644
--- a/app/src/events/keycode_state_changed.c
+++ b/app/src/events/keycode_state_changed.c
@@ -7,4 +7,4 @@
 #include <kernel.h>
 #include <zmk/events/keycode-state-changed.h>
 
-ZMK_EVENT_IMPL(keycode_state_changed);
\ No newline at end of file
+ZMK_EVENT_IMPL(keycode_state_changed);