feat(split): add peripheral changed event on central

Add a new event for when any peripheral connects or disconnects from the central

Author: ReFil

app/CMakeLists.txt

@@ -95,7 +95,13 @@ target_sources_ifdef(CONFIG_ZMK_BATTERY_REPORTING app PRIVATE src/battery.c)
 
 target_sources_ifdef(CONFIG_ZMK_HID_INDICATORS app PRIVATE src/events/hid_indicators_changed.c)
 
-target_sources_ifdef(CONFIG_ZMK_SPLIT app PRIVATE src/events/split_peripheral_status_changed.c)
+if (CONFIG_ZMK_SPLIT)
+  if(CONFIG_ZMK_SPLIT_ROLE_CENTRAL)
+    target_sources(app PRIVATE src/events/split_central_peripheral_status_changed.c)
+  else()
+    target_sources(app PRIVATE src/events/split_peripheral_status_changed.c)
+  endif()
+endif()
 add_subdirectory(src/split)
 
 target_sources_ifdef(CONFIG_USB_DEVICE_STACK app PRIVATE src/usb.c)

app/include/zmk/events/split_central_peripheral_status_changed.h

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2024 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <zephyr/kernel.h>
+#include <zmk/event_manager.h>
+#include <zmk/split/bluetooth/central.h>
+
+struct zmk_split_central_peripheral_status_changed {
+    enum zmk_split_bt_central_peripheral_source_state state;
+    uint8_t slot;
+};
+
+ZMK_EVENT_DECLARE(zmk_split_central_peripheral_status_changed);

app/include/zmk/split/bluetooth/central.h

@@ -4,6 +4,12 @@
 #include <zephyr/bluetooth/addr.h>
 #include <zmk/behavior.h>
 
+enum zmk_split_bt_central_peripheral_source_state {
+    PERIPHERAL_SLOT_STATE_OPEN,
+    PERIPHERAL_SLOT_STATE_CONNECTING,
+    PERIPHERAL_SLOT_STATE_CONNECTED,
+};
+
 #if IS_ENABLED(CONFIG_ZMK_SPLIT_PERIPHERAL_HID_INDICATORS)
 #include <zmk/hid_indicators_types.h>
 #endif // IS_ENABLED(CONFIG_ZMK_SPLIT_PERIPHERAL_HID_INDICATORS)

app/src/events/split_central_peripheral_status_changed.c

@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) 2024 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zephyr/kernel.h>
+#include <zmk/events/split_central_peripheral_status_changed.h>
+
+ZMK_EVENT_IMPL(zmk_split_central_peripheral_status_changed);

app/src/split/bluetooth/central.c

@@ -25,10 +25,12 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 #include <zmk/sensors.h>
 #include <zmk/split/bluetooth/uuid.h>
 #include <zmk/split/bluetooth/service.h>
+#include <zmk/split/bluetooth/central.h>
 #include <zmk/event_manager.h>
 #include <zmk/events/position_state_changed.h>
 #include <zmk/events/sensor_event.h>
 #include <zmk/events/battery_state_changed.h>
+#include <zmk/events/split_central_peripheral_status_changed.h>
 #include <zmk/pointing/input_split.h>
 #include <zmk/hid_indicators_types.h>
 #include <zmk/physical_layouts.h>
@@ -37,14 +39,8 @@ static int start_scanning(void);
 
 #define POSITION_STATE_DATA_LEN 16
 
-enum peripheral_slot_state {
-    PERIPHERAL_SLOT_STATE_OPEN,
-    PERIPHERAL_SLOT_STATE_CONNECTING,
-    PERIPHERAL_SLOT_STATE_CONNECTED,
-};
-
 struct peripheral_slot {
-    enum peripheral_slot_state state;
+    enum zmk_split_bt_central_peripheral_source_state state;
     struct bt_conn *conn;
     struct bt_gatt_discover_params discover_params;
     struct bt_gatt_subscribe_params subscribe_params;
@@ -965,6 +961,10 @@ static void split_central_connected(struct bt_conn *conn, uint8_t conn_err) {
 
     confirm_peripheral_slot_conn(conn);
     split_central_process_connection(conn);
+    raise_zmk_split_central_peripheral_status_changed(
+        (struct zmk_split_central_peripheral_status_changed){
+            .state = peripherals[peripheral_slot_index_for_conn(conn)].state,
+            .slot = peripheral_slot_index_for_conn(conn)});
 }
 
 static void split_central_disconnected(struct bt_conn *conn, uint8_t reason) {
@@ -988,6 +988,11 @@ static void split_central_disconnected(struct bt_conn *conn, uint8_t reason) {
 
     err = release_peripheral_slot_for_conn(conn);
 
+    raise_zmk_split_central_peripheral_status_changed(
+        (struct zmk_split_central_peripheral_status_changed){
+            .state = peripherals[peripheral_slot_index_for_conn(conn)].state,
+            .slot = peripheral_slot_index_for_conn(conn)});
+
     if (err < 0) {
         return;
     }