1 files changed, 69 insertions, 0 deletions
diff --git a/users/drashna/keyrecords/caps_word.c b/users/drashna/keyrecords/caps_word.c
new file mode 100644
index 0000000000..731568328a
--- /dev/null
+++ b/users/drashna/keyrecords/caps_word.c
@@ -0,0 +1,69 @@
+// Copyright 2021 Google LLC.
+// SPDX-License-Identifier: Apache-2.0
+
+#include "caps_word.h"
+
+bool caps_word_enabled = false;
+bool caps_word_shifted = false;
+
+bool process_caps_word(uint16_t keycode, keyrecord_t* record) {
+    if (!caps_word_enabled) {
+        // Pressing both shift keys at the same time enables caps word.
+        if (((get_mods() | get_oneshot_mods()) & MOD_MASK_SHIFT) == MOD_MASK_SHIFT) {
+            clear_mods();
+            clear_oneshot_mods();
+            caps_word_shifted = false;
+            caps_word_enabled = true;
+            return false;
+        }
+        return true;
+    }
+
+    if (!record->event.pressed) {
+        return true;
+    }
+
+    if (!((get_mods() | get_oneshot_mods()) & ~MOD_MASK_SHIFT)) {
+        switch (keycode) {
+            case QK_MOD_TAP ... QK_MOD_TAP_MAX:
+            case QK_LAYER_TAP ... QK_LAYER_TAP_MAX:
+                // Earlier return if this has not been considered tapped yet.
+                if (record->tap.count == 0) {
+                    return true;
+                }
+                // Get the base tapping keycode of a mod- or layer-tap key.
+                keycode &= 0xff;
+        }
+
+        switch (keycode) {
+            // Letter keys should be shifted.
+            case KC_A ... KC_Z:
+                if (!caps_word_shifted) {
+                    register_code(KC_LSFT);
+                }
+                caps_word_shifted = true;
+                return true;
+
+            // Keycodes that continue caps word but shouldn't get shifted.
+            case KC_1 ... KC_0:
+            case KC_BSPC:
+            case KC_MINS:
+            case KC_UNDS:
+                if (caps_word_shifted) {
+                    unregister_code(KC_LSFT);
+                }
+                caps_word_shifted = false;
+                return true;
+
+                // Any other keycode disables caps word.
+        }
+    }
+
+    // Disable caps word.
+    caps_word_enabled = false;
+    if (caps_word_shifted) {
+        unregister_code(KC_LSFT);
+    }
+    caps_word_shifted = false;
+    return true;
+}