How to create a scroll view with fixed footer with Flutter?

The accepted solution works in many cases, but it becomes tricky when you want to use something like a ListView because it can't provide an intrinsic height. I tried to find some different solution, and turns out I could, and it seems more flexible. I managed to solve this situation using slivers. Where the content is inside a sliver, and the footer is also inside a sliver.

Tip: Watch "The Boring Flutter Development Show, Ep. 12", which is all about slivers.

return Scaffold(
  body: CustomScrollView(
    shrinkWrap: true,
    slivers: [
      SliverToBoxAdapter(
        child: Column(
          children: [
            //content widgets
          ],
        ),
      ),
      SliverFillRemaining(
        hasScrollBody: false,
        child: Column(
          mainAxisAlignment: MainAxisAlignment.end,
          children: [
            //footer widgets,
          ],
        ),
      ),
    ],
  ),
);

How I solved this was to wrap the fixed Footer and The SingleChildScrollView in a Stack widget then align the Footer accordingly.

class ScrollableFooter extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Stack(
      children: <Widget>[
        SingleChildScrollView(
          child: Container(
            padding: EdgeInsets.all(5),
            child: Column(
              children: <Widget>[
                // Your body widgets here
              ],
            ),
          ),
        ),
        Align(
          alignment: Alignment.bottomCenter,
          child: // Your fixed Footer here,
        ),
      ],
    );
  }
}

Even though the Rémi answer being right, I've actually found an easier way to achieve what I was looking for by just combining the LayoutBuilder with the IntrinsicHeight.

class ScrollableFooter extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return LayoutBuilder(
        builder: (BuildContext context, BoxConstraints constraints) {
      return SingleChildScrollView(
        child: ConstrainedBox(
          constraints: constraints.copyWith(
            minHeight: constraints.maxHeight,
            maxHeight: double.infinity,
          ),
          child: IntrinsicHeight(
            child: Column(
              children: <Widget>[
               // Your body widgets here
                Expanded(
                  child: Align(
                    alignment: Alignment.bottomCenter,
                    child: // Your footer widget
                  ),
                ),
              ],
            ),
          ),
        ),
      );
    });
  }
}

For those who were looking to implement just footer with scrollview in a simple way, below code might help :

Scaffold(
      appBar: buildAppBar('Some cool appbar'),
      body: Column(
        children: [
          Expanded(
            child: SingleChildScrollView(
              child: Column(
                children: [
                  PackageCard(),
                  PackageCard(),
                  PackageCard(),
                ],
              ),
            ),
          ),
          Container(
            child: Text('Your super cool Footer'),
            color: Colors.amber,
          )
        ],
      ),
    );

Visual representation:-

---Column
    |
    |---Expanded--
                 |-SingleChildScrollView (column /YOUR SCROLLABLE VIEW)
    |
    |-Container(YOUR FOOTER)

I used expanded with SinglechildScrollView over here