Lift out `isModifier` into its own function

To make it easier to extend the plugin, to teach it to highlight keys other than
the traditional modifiers, lift the code that checks for a modifier into its own
function.

No functional change, just refactoring.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

src/Kaleidoscope/LED-ActiveModColor.cpp

@@ -33,6 +33,19 @@ void ActiveModColorEffect::begin(void) {
   loop_hook_use(loopHook);
 }
 
+bool ActiveModColorEffect::isModifier(Key key) {
+  if (key.raw >= ranges::OSM_FIRST && key.raw <= ranges::OSM_LAST) {
+    uint8_t idx = key.raw - ranges::OSM_FIRST;
+    key.flags = 0;
+    key.keyCode = Key_LeftControl.keyCode + idx;
+  }
+
+  if (key.raw < Key_LeftControl.raw || key.raw > Key_RightGui.raw)
+    return false;
+
+  return true;
+}
+
 void ActiveModColorEffect::loopHook(bool is_post_clear) {
   if (is_post_clear)
     return;
@@ -41,13 +54,7 @@ void ActiveModColorEffect::loopHook(bool is_post_clear) {
     for (byte c = 0; c < COLS; c++) {
       Key k = Layer.lookup(r, c);
 
-      if (k.raw >= ranges::OSM_FIRST && k.raw <= ranges::OSM_LAST) {
+      if (!isModifier(k))
-        uint8_t idx = k.raw - ranges::OSM_FIRST;
-        k.flags = 0;
-        k.keyCode = Key_LeftControl.keyCode + idx;
-      }
-
-      if (k.raw < Key_LeftControl.raw || k.raw > Key_RightGui.raw)
         continue;
 
       if (hid::isModifierKeyActive(k))

src/Kaleidoscope/LED-ActiveModColor.h

@@ -31,6 +31,7 @@ class ActiveModColorEffect : public KaleidoscopePlugin {
   static cRGB highlight_color;
 
  private:
+  static bool isModifier(Key key);
   static void loopHook(bool is_post_clear);
 };
 }