import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

/// create by 张风捷特烈 on 2020/9/21
/// contact me by email 1981462002@qq.com
/// 说明: 252 DraggableScrollableSheet 拖滑页 可拖动和滑动的Sheet，可指定最大、最小、最初的分度现在滑动范围。构造器builder需要返回一个可滑动组件。
//    {
//      "widgetId": 252,
//      "name": 'DraggableScrollableSheet基本使用',
//      "priority": 1,
//      "subtitle":
//          "【initialChildSize】 : 初始分度   【double】\n"
//          "【minChildSize】 : 最小分度   【double】\n"
//          "【maxChildSize】 : 最大分度   【double】\n"
//          "【builder】 : 滑动组件构造器   【ScrollableWidgetBuilder】\n"
//          "【expand】 : 是否延展   【bool】",
//    }

class DraggableScrollableSheetDemo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      padding: EdgeInsets.all(10),
      child: ElevatedButton(
        onPressed: () {
          Navigator.push(
            context,
            MaterialPageRoute(
                builder: (context) => DraggableScrollableSheetPage()),
          );
        },
        child: Text("进入 DraggableScrollableSheet 测试页"),
      ),
    );
  }
}

class DraggableScrollableSheetPage extends StatelessWidget {
  final data = <Color>[
    Colors.orange[50],
    Colors.orange[100],
    Colors.orange[200],
    Colors.orange[300],
    Colors.orange[400],
    Colors.orange[500],
    Colors.orange[600],
    Colors.orange[700],
    Colors.orange[800],
    Colors.orange[900],
    Colors.red[50],
    Colors.red[100],
    Colors.red[200],
    Colors.red[300],
    Colors.red[400],
    Colors.red[500],
    Colors.red[600],
    Colors.red[700],
    Colors.red[800],
    Colors.red[900],
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("DraggableScrollableSheet"),
      ),
      body: SizedBox.expand(
          child: DraggableScrollableSheet(
        initialChildSize: 0.3,
        minChildSize: 0.2,
        maxChildSize: 0.5,
        expand: true,
        builder: (BuildContext context, ScrollController scrollController)=>
           ListView.builder(
            controller: scrollController,
            itemCount: data.length,
            itemBuilder: buildColorItem,
          ),
      )),
    );
  }

  Widget buildColorItem(BuildContext context, int index) {
    return Container(
      alignment: Alignment.center,
      height: 60,
      color: data[index],
      child: Text(
        colorString(data[index]),
        style: TextStyle(color: Colors.white, shadows: [
          Shadow(color: Colors.black, offset: Offset(.5, .5), blurRadius: 2)
        ]),
      ),
    );
  }

  String colorString(Color color) =>
      "#${color.value.toRadixString(16).padLeft(8, '0').toUpperCase()}";
}