message: Use `std::size_t` to get IconGrid itemName
diff: @@ -52,7 +52,7 @@ public:
  void iconSize(int newSsize);
  void iconMargin(int newMargin);
  - const std::string& itemName(int index) const { return mIconItemList[index].name; }
  + const std::string& itemName(std::size_t index) const { return mIconItemList[index].name; }
  int selectionIndex() const { return static_cast<int>(mCurrentSelection); }
  