1 files changed, 58 insertions, 0 deletions
diff --git a/users/ericgebhart/extensions/swapper.c b/users/ericgebhart/extensions/swapper.c
new file mode 100644
index 0000000000..988a99e602
--- /dev/null
+++ b/users/ericgebhart/extensions/swapper.c
@@ -0,0 +1,58 @@
+/*
+  Copyright 2022 Eric Gebhart <e.a.gebhart@gmail.com, @possumvibes,@Callum.
+
+  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 swapper by @Possumvibes and @Callum
+
+#include "swapper.h"
+
+swapper_state_t swapper_states[] = {
+#ifdef SWAPPER_ENABLE
+#include "swapper.def"
+#endif
+};
+uint8_t         NUM_SWAPPER_STATES = sizeof(swapper_states) / sizeof(swapper_state_t);
+
+// Based on https://github.com/callum-oakley/qmk_firmware/tree/master/users/callum
+void process_swappers(uint16_t keycode, keyrecord_t *record) {
+#ifdef SWAPPER_ENABLE
+  swapper_state_t *curr_state = NULL;
+  for (int i = 0; i < NUM_SWAPPER_STATES; ++i) {
+    curr_state = &swapper_states[i];
+
+    if (keycode == curr_state->forward_trigger) {
+      if (record->event.pressed) {
+        if (!curr_state->active) {
+          curr_state->active = true;
+          register_code16(curr_state->mod);
+        }
+        register_code16(curr_state->forward);
+      } else {
+        unregister_code16(curr_state->forward);
+        // Don't unregister curr_state->mod until some other key is hit or released.
+      }
+    } else if (curr_state->active && keycode == curr_state->reverse_trigger) {
+      if (record->event.pressed) {
+        register_code16(curr_state->reverse);
+      } else {
+        unregister_code16(curr_state->reverse);
+      }
+    } else if (curr_state->active) {
+      unregister_code16(curr_state->mod);
+      curr_state->active = false;
+    }
+  }
+#endif
+}