From 4e6d593a87972fe108b11515c2dae29b2e234756 Mon Sep 17 00:00:00 2001
From: elpekenin <elpekenin@elpekenin.dev>
Date: Sat, 23 Mar 2024 12:28:00 +0100
Subject: [PATCH] feat: default layer setter

---
 app/include/zmk/keymap.h |  1 +
 app/src/keymap.c         | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/app/include/zmk/keymap.h b/app/include/zmk/keymap.h
index 0d7dbaf3..c8a1da63 100644
--- a/app/include/zmk/keymap.h
+++ b/app/include/zmk/keymap.h
@@ -15,6 +15,7 @@
 typedef uint32_t zmk_keymap_layers_state_t;
 
 uint8_t zmk_keymap_layer_default(void);
+int zmk_keymap_layer_set_default(uint8_t layer);
 zmk_keymap_layers_state_t zmk_keymap_layer_state(void);
 bool zmk_keymap_layer_active(uint8_t layer);
 uint8_t zmk_keymap_highest_layer_active(void);
diff --git a/app/src/keymap.c b/app/src/keymap.c
index 94bd1204..d430aef3 100644
--- a/app/src/keymap.c
+++ b/app/src/keymap.c
@@ -108,6 +108,29 @@ static inline int set_layer_state(uint8_t layer, bool state) {
 
 uint8_t zmk_keymap_layer_default(void) { return _zmk_keymap_layer_default; }
 
+int zmk_keymap_layer_set_default(uint8_t layer) {
+    int ret = 0;
+    uint8_t prev_default = _zmk_keymap_layer_default;
+
+    ret = set_layer_state(layer, true);
+    if (ret < 0) {
+        LOG_WRN("Could not turn on the new default layer, bailing out.");
+        return ret;
+    }
+
+    _zmk_keymap_layer_default = layer;
+    ret = set_layer_state(prev_default, false);
+    if (ret < 0) {
+        LOG_WRN("Could not disable current default layer, undoing changes.");
+        _zmk_keymap_layer_default = prev_default;
+        set_layer_state(layer, false);
+        return ret;
+    }
+
+    LOG_DBG("default_layer_changed: %d", layer);
+    return 0;
+}
+
 zmk_keymap_layers_state_t zmk_keymap_layer_state(void) { return _zmk_keymap_layer_state; }
 
 bool zmk_keymap_layer_active_with_state(uint8_t layer, zmk_keymap_layers_state_t state_to_test) {