Flutter set custom heights for DraggableScrollableSheet - flutter

Question

when i use DraggableScrollableSheet i have some problem of that, they are:
how can i set minimum height after dragging that to bottom
how can i set minimum height
how can i set maximum height
how can i know stick to top like with stick to appBar, detecting maximum size
SizedBox.expand(
child: SlideTransition(
position: _draggableBottomSheetTween.animate(_draggableBottomSheetController),
child: DraggableScrollableSheet(
builder: (BuildContext context, ScrollController scrollController) {
return ClipRRect(
borderRadius: BorderRadius.only(
topLeft: Radius.circular(10.0),
topRight: Radius.circular(10.0)
),
child: Container(
height: 500.0,
color: pageBackgroundColor,
child: ListView.builder(
controller: scrollController,
itemCount: 5,
itemBuilder: (BuildContext context, int index) {
return ListTile(title: Text('Item $index'));
},
),
),
);
},
),
),
),

Answer 1

Here is the full solution.
class HomePage extends StatefulWidget {
#override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> with SingleTickerProviderStateMixin {
AnimationController _controller;
Duration _duration = Duration(milliseconds: 500);
Tween<Offset> _tween = Tween(begin: Offset(0, 1), end: Offset(0, 0));
double _height, min = 0.1, initial = 0.3, max = 0.7;
#override
void initState() {
super.initState();
_controller = AnimationController(vsync: this, duration: _duration);
}
#override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButton: GestureDetector(
child: FloatingActionButton(
child: AnimatedIcon(icon: AnimatedIcons.menu_close, progress: _controller),
elevation: 5,
backgroundColor: Colors.deepOrange,
foregroundColor: Colors.white,
onPressed: () async {
if (_controller.isDismissed)
_controller.forward();
else if (_controller.isCompleted) _controller.reverse();
},
),
),
body: SizedBox.expand(
child: Stack(
children: <Widget>[
FlutterLogo(size: 500),
SizedBox.expand(
child: SlideTransition(
position: _tween.animate(_controller),
child: DraggableScrollableSheet(
minChildSize: min, // 0.1 times of available height, sheet can't go below this on dragging
maxChildSize: max, // 0.7 times of available height, sheet can't go above this on dragging
initialChildSize: initial, // 0.1 times of available height, sheet start at this size when opened for first time
builder: (BuildContext context, ScrollController controller) {
if (controller.hasClients) {
var dimension = controller.position.viewportDimension;
_height ??= dimension / initial;
if (dimension >= _height * max * 0.9)
print("at top");
else if (dimension <= _height * min * 1.1)
print("at bottom");
}
return ClipRRect(
borderRadius: BorderRadius.only(topLeft: Radius.circular(20.0), topRight: Radius.circular(20.0)),
child: Container(
height: 500.0,
color: Colors.blue[800],
child: ListView.builder(
controller: controller,
itemCount: 5,
itemBuilder: (BuildContext context, int index) {
return ListTile(title: Text('Item $index'));
},
),
),
);
},
),
),
),
],
),
),
);
}
}