1 files changed, 81 insertions, 0 deletions
diff --git a/users/ericgebhart/caps_word.c b/users/ericgebhart/caps_word.c
new file mode 100644
index 0000000000..ba81c15d66
--- /dev/null
+++ b/users/ericgebhart/caps_word.c
@@ -0,0 +1,81 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+// For full documentation, see
+// https://getreuer.info/posts/keyboards/caps-word
+
+#include "caps_word.h"
+
+bool process_caps_word(uint16_t keycode, keyrecord_t* record) {
+  static bool caps_word_enabled = false;
+  static bool shifted = false;
+#ifndef NO_ACTION_ONESHOT
+  const uint8_t mods = get_mods() | get_oneshot_mods();
+#else
+  const uint8_t mods = get_mods();
+#endif  // NO_ACTION_ONESHOT
+
+  if (!caps_word_enabled) {
+    // Pressing both shift keys at the same time enables caps word.
+    if ((mods & MOD_MASK_SHIFT) == MOD_MASK_SHIFT) {
+      clear_mods();
+#ifndef NO_ACTION_ONESHOT
+      clear_oneshot_mods();
+#endif  // NO_ACTION_ONESHOT
+      shifted = false;
+      caps_word_enabled = true;
+      return false;
+    }
+    return true;
+  }
+
+  if (!record->event.pressed) { return true; }
+
+  if (!(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 (!shifted) { register_code(KC_LSFT); }
+      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 (shifted) { unregister_code(KC_LSFT); }
+      shifted = false;
+      return true;
+
+      // Any other keycode disables caps word.
+    }
+  }
+
+  // Disable caps word.
+  caps_word_enabled = false;
+  if (shifted) { unregister_code(KC_LSFT); }
+  shifted = false;
+  return true;
+}