Flutter: how to make a list that always scrolls to the bottom?

Question

I am trying to make a list that is basically a log screen. That said, I need the list to keep scrolling to bottom all the time.

How this can be done?

Answer 1

Set reverse: true on the ListView widget and reverse the children list.

ListView(
  // Start scrolled to the bottom by default and stay there.
  reverse: true,
  children: widget.children.reversed.toList(growable: false),
),

If you have a very long list and reversing is expensive, you can reverse the index rather than the whole list using ListView.builder

ListView.builder(
    reverse: true,
    itemCount: items.length,
    itemBuilder: (context, index) {
      final reversedIndex = items.length - 1 - index;
      final item = items[reversedIndex];
      return MyWidget(item);
    }
)

I got this from Günter's comment above. Thanks!

Answer 2

I could make this work by using a Timer but probably should have a better way to do this. My workaround was:

1. Define a ScrollController() and attach it to the listView:

ListView.builder(
      controller: _scrollController,
      itemCount: _logLines.values.length,
      itemBuilder: (context, index) => _getLogLine(index),
    )

2. Override your page initState method and set a Timer inside it like:

 @override
  void initState() {
      super.initState();
      Timer.periodic(Duration(milliseconds: 100), (timer) {
        if (mounted) {
            _scrollToBottom();
        } else {
          timer.cancel();
        }
      });
    }

3. Define a method _scrollToBottom() that calls:

   _scrollController.jumpTo(_scrollController.position.maxScrollExtent);