Flutter : How to retrieve index from map (List)

Question

I'm currently stuck on the flutter development where I need to retrieve the index from map to other parts of the Scaffold. Is it possible to retrieve the index value from the map below into other parts of Scaffold (Floating Action Button)?

  Iterable<int> get positiveIntegers sync* {
    int i = articleList.length - 1;
    while (true) yield i--;
  }

  @override
  Widget build(BuildContext context) {
    int getLength = articleList.length;
    var list = positiveIntegers.take(getLength).toList();

    return Scaffold(
      appBar: AppBar(
        title: new Text(
          'Popular',
          textAlign: TextAlign.center,
        ),
        textTheme: TextTheme(
            title: TextStyle(
                fontSize: 16,
                fontWeight: FontWeight.w700,
                color: Colors.black)),
        backgroundColor: Colors.white,
        centerTitle: true,
        elevation: 0.0,
      ),
      body: SwipeStack(
          children: list.map((index) {
              ...
          }
      ),
      floatingActionButton: Container(
        margin: EdgeInsets.only(top: 25, bottom: 25, left: 20),
        alignment: Alignment(0, 1),
        child: new Row(
          children: <Widget>[
            RawMaterialButton(
              onPressed: () {
                if (isOutOfCards == true) {
                  setState(() {
                    isOutOfCards = false;
                  });
                }
              },
              child: iconBuild(context),
              shape: new CircleBorder(),
              fillColor: Colors.red[700],
              splashColor: Colors.transparent,
              highlightColor: Colors.transparent,
              padding: const EdgeInsets.all(11),
            ),
            buttonTextBuild(context),
          ],
        ),
      ),
    );
  }

  Widget buttonTextBuild(BuildContext context) {
    if (isOutOfCards == false) {
      return Container(
          child: Text('$cardIndex/${articleList.length}',
              textAlign: TextAlign.left,
              style: TextStyle(
                  fontSize: 12.75,
                  fontWeight: FontWeight.w500,
                  letterSpacing: 1)));
    } else {
      return Container(
          child: Text('Start Again',
              textAlign: TextAlign.left,
              style: TextStyle(
                  fontSize: 12.75,
                  fontWeight: FontWeight.w500,
                  letterSpacing: 1)));
    }
  }

Like the code above I want to retrieve the 'index' from the list.map and pass it to the cardIndex inside buttonTextBuild.

Answer 1

You can use the enumerate function from the quiver package:

children: enumerate(list).map((indexedValue) {
  var index = indexedValue.index;
  var value = indexedValue.value;
  ...
}),

Answer 2

You can do this like that:

            children: [
              for(int index = 0; index < list.length; index++)
                Text(list[index])
            ]

Text widget is just example, you can use whatever widget you need or call function passing list[index] to get item