BottomNavigationBar({Key key, @required List<BottomNavigationBarItem> items, ValueChanged<int> onTap, int currentIndex: 0, BottomNavigationBarType type: BottomNavigationBarType.fixed, Color fixedColor, double iconSize: 24.0 })

Creates a bottom navigation bar, typically used in a Scaffold where it is provided as the bottomNavigationBar argument.

The arguments items and type should not be null.

The number of items passed should be equal or greater than 2.

Passing a null fixedColor will cause a fallback to the theme's primary color.

Source 

BottomNavigationBar({
  Key key,
  @required this.items,
  this.onTap,
  this.currentIndex: 0,
  this.type: BottomNavigationBarType.fixed,
  this.fixedColor,
  this.iconSize: 24.0,
}) : super(key: key) {
  assert(items != null);
  assert(items.length >= 2);
  assert(0 <= currentIndex && currentIndex < items.length);
  assert(type != null);
  assert(type == BottomNavigationBarType.fixed || fixedColor == null);
  assert(iconSize != null);
}