Method refreshIfDirty

src/SdCardFontSystem.h:42–46

If the registry is dirty, re-scan the SD card now and clear the flag. Used by the web UI so uploaded/deleted fonts appear in the list without waiting for the reader activity to run ensureLoaded().

  /// Used by the web UI so uploaded/deleted fonts appear in the list
  /// without waiting for the reader activity to run ensureLoaded().
  void refreshIfDirty() {
    if (registryDirty_.exchange(false, std::memory_order_acquire)) {
      registry_.discover();
    }
  }

 private:
  SdCardFontRegistry registry_;