hash-wallet/lib/src/widgets/standard_list.dart

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

class StandardListRow extends StatelessWidget {
  StandardListRow(
      {@required this.title, @required this.isSelected, this.onTap});

  final String title;
  final bool isSelected;
  final void Function(BuildContext context) onTap;

  @override
  Widget build(BuildContext context) {
    final leading = buildLeading(context);
    final trailing = buildTrailing(context);

    return InkWell(
        onTap: () => onTap?.call(context),
        child: Container(
            color: _backgroundColor(context),
            height: 56,
            padding: EdgeInsets.only(left: 24, right: 24),
            child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: <Widget>[
                  if (leading != null) leading,
                  buildCenter(context, hasLeftOffset: leading != null),
                  if (trailing != null) trailing
                ])));
  }

  Widget buildLeading(BuildContext context) => null;

  Widget buildCenter(BuildContext context, {@required bool hasLeftOffset}) {
    // FIXME: find better way for keep text on left side.
    return Expanded(
        child: Row(mainAxisAlignment: MainAxisAlignment.start, children: [
      if (hasLeftOffset) SizedBox(width: 10),
      Text(title,
          style: TextStyle(
              fontSize: 14,
              fontWeight: FontWeight.w500,
              color: _titleColor(context)))
    ]));
  }

  Widget buildTrailing(BuildContext context) => null;

  Color _titleColor(BuildContext context) => isSelected
      ? Color.fromRGBO(20, 200, 71, 1)
      : Theme.of(context).primaryTextTheme.title.color;

  Color _backgroundColor(BuildContext context) {
//    return Theme.of(context).accentTextTheme.subtitle.decorationColor;
    return Theme.of(context).accentTextTheme.title.backgroundColor;
  }
}

class SectionHeaderListRow extends StatelessWidget {
  @override
  Widget build(BuildContext context) => Column(children: [
        StandardListSeparator(),
        Container(width: double.infinity, height: 40, color: Colors.white),
        StandardListSeparator()
      ]);
}

class StandardListSeparator extends StatelessWidget {
  StandardListSeparator({this.padding});

  final EdgeInsets padding;

  @override
  Widget build(BuildContext context) {
    return Container(
        height: 1,
        padding: padding,
        color: Theme.of(context).accentTextTheme.title.backgroundColor,
        child: Container(height: 1, color: Color.fromRGBO(219, 227, 243, 1)));
  }
}

class StandardList extends StatelessWidget {
  StandardList({@required this.itemCount, @required this.itemBuilder});

  final int itemCount;
  final IndexedWidgetBuilder itemBuilder;

  @override
  Widget build(BuildContext context) {
    return ListView.separated(
        separatorBuilder: (_, __) =>
            StandardListSeparator(padding: EdgeInsets.only(left: 24)),
        itemCount: itemCount,
        itemBuilder: itemBuilder);
  }
}

class SectionStandardListItem {
  SectionStandardListItem({this.hasFullSeparator = false, this.child});

  final bool hasFullSeparator;
  final Widget child;
}

class SectionStandardList extends StatelessWidget {
  SectionStandardList(
      {@required this.itemCounter,
      @required this.itemBuilder,
      @required this.sectionCount,
      BuildContext context})
      : totalRows = transform(context, sectionCount, itemCounter, itemBuilder);

  final int sectionCount;
  final int Function(int sectionIndex) itemCounter;
  final Widget Function(BuildContext context, int sectionIndex, int itemIndex)
      itemBuilder;
  final List<Widget> totalRows;

  static List<Widget> transform(
      BuildContext context,
      int sectionCount,
      int Function(int sectionIndex) itemCounter,
      Widget Function(BuildContext context, int sectionIndex, int itemIndex)
          itemBuilder) {
    final items = <Widget>[];

    for (var sectionIndex = 0; sectionIndex < sectionCount; sectionIndex++) {
      if (sectionIndex == 0) {
        items.add(StandardListSeparator());
      }

      final itemCount = itemCounter(sectionIndex);

      for (var itemIndex = 0; itemIndex < itemCount; itemIndex++) {
        final item = itemBuilder(context, sectionIndex, itemIndex);

        items.add(item);
      }

      items.add(sectionIndex + 1 != sectionCount
          ? SectionHeaderListRow()
          : StandardListSeparator());
    }

    return items;
  }

  @override
  Widget build(BuildContext context) {
    return ListView.separated(
        separatorBuilder: (_, index) {
          final row = totalRows[index];

          if (row is StandardListSeparator || row is SectionHeaderListRow) {
            return Container();
          }

          final nextRow = totalRows[index + 1];

          // If current row is pre last and last row is separator.
          if (nextRow is StandardListSeparator ||
              nextRow is SectionHeaderListRow) {
            return Container();
          }

          return StandardListSeparator(padding: EdgeInsets.only(left: 24));
        },
        itemCount: totalRows.length,
        itemBuilder: (_, index) => totalRows[index]);
  }
}