More reshaping

src/util/ButtonNavigator.h

@@ -45,9 +45,9 @@ class ButtonNavigator final {
   [[nodiscard]] static int nextIndex(int currentIndex, const std::vector<bool>& selectable);
   [[nodiscard]] static int previousIndex(int currentIndex, const std::vector<bool>& selectable);
   [[nodiscard]] static int nextIndex(int currentIndex, int totalItems,
-                                    const std::function<bool(int index)>& isSelectable);
+                                     const std::function<bool(int index)>& isSelectable);
   [[nodiscard]] static int previousIndex(int currentIndex, int totalItems,
-                                        const std::function<bool(int index)>& isSelectable);
+                                         const std::function<bool(int index)>& isSelectable);
 
   [[nodiscard]] int nextIndex(int currentIndex) const;
   [[nodiscard]] int previousIndex(int currentIndex) const;

src/util/MenuItemHelpers.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <I18n.h>
+
+#include <functional>
+#include <type_traits>
+#include <vector>
+
+// Generic helper for constructing separator rows in menu item vectors.
+// The item type must have an `action`, an `isSeparator`, and either a `labelId` or `nameId` member.
+template <typename ItemType>
+inline ItemType makeSeparatorMenuItem(StrId labelId) {
+  ItemType item{};
+  if constexpr (std::is_member_object_pointer_v<decltype(&ItemType::action)>) {
+    item.action = static_cast<decltype(item.action)>(0);
+  }
+  if constexpr (std::is_member_object_pointer_v<decltype(&ItemType::labelId)>) {
+    item.labelId = labelId;
+  } else if constexpr (std::is_member_object_pointer_v<decltype(&ItemType::nameId)>) {
+    item.nameId = labelId;
+  } else {
+    static_assert(sizeof(ItemType) == 0,
+                  "makeSeparatorMenuItem requires ItemType with labelId or nameId member");
+  }
+  item.isSeparator = true;
+  return item;
+}
+
+// Generic helper for creating a selectable predicate for menu lists.
+// The item type must have an `isSeparator` member.
+template <typename ItemType>
+inline std::function<bool(int)> makeSelectablePredicate(const std::vector<ItemType>& items) {
+  return
+      [&items](int index) { return index >= 0 && index < static_cast<int>(items.size()) && !items[index].isSeparator; };
+}
+
+template <typename ItemType>
+inline std::function<bool(int)> makeSelectablePredicate(const std::vector<ItemType>& items, int indexOffset,
+                                                        bool firstIndexSelectable) {
+  return [&items, indexOffset, firstIndexSelectable](int index) {
+    if (firstIndexSelectable && index == 0) {
+      return true;
+    }
+
+    const int itemIndex = index - indexOffset;
+    return itemIndex >= 0 && itemIndex < static_cast<int>(items.size()) && !items[itemIndex].isSeparator;
+  };
+}