1 files changed, 57 insertions, 0 deletions
diff --git a/users/callum/oneshot.c b/users/callum/oneshot.c
new file mode 100644
index 0000000000..33ec3895e2
--- /dev/null
+++ b/users/callum/oneshot.c
@@ -0,0 +1,57 @@
+#include "oneshot.h"
+
+void update_oneshot(
+    oneshot_state *state,
+    uint16_t mod,
+    uint16_t trigger,
+    uint16_t keycode,
+    keyrecord_t *record
+) {
+    if (keycode == trigger) {
+        if (record->event.pressed) {
+            // Trigger keydown
+            if (*state == os_up_unqueued) {
+                register_code(mod);
+            }
+            *state = os_down_unused;
+        } else {
+            // Trigger keyup
+            switch (*state) {
+            case os_down_unused:
+                // If we didn't use the mod while trigger was held, queue it.
+                *state = os_up_queued;
+                break;
+            case os_down_used:
+                // If we did use the mod while trigger was held, unregister it.
+                *state = os_up_unqueued;
+                unregister_code(mod);
+                break;
+            default:
+                break;
+            }
+        }
+    } else {
+        if (record->event.pressed) {
+            if (is_oneshot_cancel_key(keycode) && *state != os_up_unqueued) {
+                // Cancel oneshot on designated cancel keydown.
+                *state = os_up_unqueued;
+                unregister_code(mod);
+            }
+        } else {
+            if (!is_oneshot_ignored_key(keycode)) {
+                // On non-ignored keyup, consider the oneshot used.
+                switch (*state) {
+                case os_down_unused:
+                    *state = os_down_used;
+                    break;
+                case os_up_queued:
+                    *state = os_up_unqueued;
+                    unregister_code(mod);
+                    break;
+                default:
+                    break;
+                }
+            }
+        }
+    }
+}