可滚动面板

scrollable_panel

drag to expand and then can scroll contents. similar "Nearby spots" panel on google map app.

https://pub.dev/packages/scrollable_panel

Panel Properties

Properties	Data Type	Description
builder	ScrollableWidgetBuilder	builder for inner panel view. ScrollableWidgetBuilder type define in draggable_scrollable_sheet.dart. provide PanelScrollController that extends ScrollController.
controller	PanelController	control panel from some interaction like button.
defaultPanelState	PanelState	set default panel state. (default value PanelState.open)
defaultPanelSize	double	set default panel height factor (default value 0.25)
minPanelSize	double	set minimum panel height factor. (default value 0)
maxPanelSize	double	set maximum panel height factor. (default value 1.0)
onOpen	VoidCallback	if non-null, this callback is called when panel state become open
onClose	VoidCallback	if non-null, this callback is called when panel state become close
onExpand	VoidCallback	if non-null, this callback is called when panel state become expand

PanelController actions

Action	Data Type	Description
open	void	open panel. panel animate to defaultPanelSize.
expand	void	expand panel. panel animate to maxPanelSize.
close	void	close panel. panel animate to minPanelSize.
animateTo	double	animate panel to value height.

Usage

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  PanelController _panelController = PanelController();
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('scrollable panel'),
      ),
      body: Stack(
        children: <Widget>[
          InkWell(
            onTap: () {
              _panelController.toDefault();
            },
            child: _FirstView(),
          ),
          ScrollablePanel(
            controller: _panelController,
            builder: (context, controller) {
              return SingleChildScrollView(
                controller: controller,
                child: _SecondView(),
              );
            },
          ),
        ],
      ),
    );
  }
}

TODO

• ~write README.md and dartdoc~
• ~null-safety support~
• ~write test code~
• add List<double> anchor property to use multi snapping point.