increase method

dynamic increase()

Implementation

increase() {
  if (highlightedIndex != widget.tabTitles.length - 1)
    setState(() {
      itemScrollController.scrollTo(
          index: highlightedIndex + 1,
          curve: Curves.fastLinearToSlowEaseIn,
          duration: Duration(milliseconds: 600));
      highlightedIndex++;
    });
}