index property

int index

The index of the currently selected tab. Changing the index also updates previousIndex, sets the animation's value to index, resets indexIsChanging to false, and notifies listeners.

To change the currently selected tab and play the animation use animateTo.

The value of index must be valid given length. If length is zero, then index will also be zero.

Implementation 

int get index => _index;
void index= (int value)

Implementation 

set index(int value) {
  _changeIndex(value);
}