feat(behavior): Add key toggle

app/src/behaviors/behavior_key_toggle.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_behavior_key_toggle
+
+#include <device.h>
+#include <drivers/behavior.h>
+#include <logging/log.h>
+
+#include <zmk/hid.h>
+#include <zmk/event_manager.h>
+#include <zmk/events/keycode_state_changed.h>
+#include <zmk/behavior.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+static int behavior_key_toggle_init(const struct device *dev) { return 0; }
+
+static int on_keymap_binding_pressed(struct zmk_behavior_binding *binding,
+                                     struct zmk_behavior_binding_event event) {
+    LOG_DBG("position %d keycode 0x%02X", event.position, binding->param1);
+    bool pressed = zmk_hid_is_pressed(binding->param1);
+    return ZMK_EVENT_RAISE(
+        zmk_keycode_state_changed_from_encoded(binding->param1, !pressed, event.timestamp));
+}
+
+static int on_keymap_binding_released(struct zmk_behavior_binding *binding,
+                                      struct zmk_behavior_binding_event event) {
+    return 0;
+}
+
+static const struct behavior_driver_api behavior_key_toggle_driver_api = {
+    .binding_pressed = on_keymap_binding_pressed,
+    .binding_released = on_keymap_binding_released,
+};
+
+#define KT_INST(n)                                                                                 \
+    DEVICE_DT_INST_DEFINE(n, behavior_key_toggle_init, NULL, NULL, NULL, APPLICATION,              \
+                          CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, &behavior_key_toggle_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(KT_INST)