1 files changed, 81 insertions, 0 deletions
diff --git a/users/ericgebhart/extensions/mod_lock.c b/users/ericgebhart/extensions/mod_lock.c
new file mode 100644
index 0000000000..c78f7cdfe8
--- /dev/null
+++ b/users/ericgebhart/extensions/mod_lock.c
@@ -0,0 +1,81 @@
+/*
+  Copyright 2022 Eric Gebhart <e.a.gebhart@gmail.com>, @possumvibes
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+// Derived from mod_lock by @possumvibes.
+
+#include "mod_lock.h"
+
+#undef MODL
+#define MODL(KEYCODE, MODKC)                    \
+  {false, MODKC, KEYCODE},
+
+#define A_KEY(KEYCODE) case KEYCODE:
+#define BLANK(...)
+
+#undef IGNORE_KC
+#define IGNORE_KC BLANK
+
+mod_lock_state_t modlock_states[] = {
+#ifdef MOD_LOCK_ENABLE
+#include "mod_lock.def"
+#endif
+};
+uint8_t        NUM_MODLOCK_STATES = sizeof(modlock_states) / sizeof(mod_lock_state_t);
+
+void process_mod_lock(uint16_t keycode, keyrecord_t *record) {
+#ifdef MOD_LOCK_ENABLE
+  mod_lock_state_t *curr_state = NULL;
+
+  for (int i = 0; i < NUM_MODLOCK_STATES; ++i) {
+    curr_state = &modlock_states[i];
+
+    if (keycode == curr_state->trigger) {
+      if (record->event.pressed) {
+        if (curr_state->locking) {
+          unregister_code(curr_state->mod);
+        } else {
+          register_code(curr_state->mod);
+        }
+
+        curr_state->locking = !curr_state->locking;
+      }
+    } else {
+      // check for cancel condition on keydown and keyup
+      if (curr_state->locking && is_mod_lock_cancel_key(keycode)) {
+        unregister_code(curr_state->mod);
+        curr_state->locking = false;
+      }
+    }
+  }
+#endif
+}
+
+#undef MODL
+#undef IGNORE_KC
+#define MODL BLANK
+#define IGNORE_KC A_KEY
+bool is_mod_lock_cancel_key(uint16_t keycode) {
+    // Mod locks are exclusively used on the nav layer.
+    // any key besides nav keys should cancel the lock.
+    switch (keycode) {
+#ifdef MOD_LOCK_ENABLE
+#include "mod_lock.def"
+#endif
+      return false;
+    default:
+            return true;
+    }
+}