Flutter 自定义 RadioListTile

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

/// 自定义 RadioListTile
class RadioListTileSuper<T> extends StatelessWidget {
  const RadioListTileSuper({
    Key key,
    this.value,
    this.groupValue,
    this.onChanged,
    this.toggleable = false,
    this.activeColor,
    this.title,
    this.subtitle,
    this.isThreeLine = false,
    this.dense,
    this.secondary,
    this.selected = false,
    this.controlAffinity = ListTileControlAffinity.platform,
    this.autofocus = false,
    this.contentPadding,
    this.shape,
    this.tileColor,
    this.selectedTileColor,
  }) : assert(toggleable != null),
        assert(isThreeLine != null),
        assert(!isThreeLine || subtitle != null),
        assert(selected != null),
        assert(controlAffinity != null),
        assert(autofocus != null),
        super(key: key);
  final T value;
  final T groupValue;
  final ValueChanged<T> onChanged;
  final bool toggleable;
  final Color activeColor;
  final Widget title;
  final Widget subtitle;
  final Widget secondary;
  final bool isThreeLine;
  final bool dense;
  final bool selected;
  final ListTileControlAffinity controlAffinity;
  final bool autofocus;
  final EdgeInsetsGeometry contentPadding;
  bool get checked => value == groupValue;
  final ShapeBorder shape;
  final Color tileColor;
  final Color selectedTileColor;

  @override
  Widget build(BuildContext context) {
    final Widget control = Radio<T>(
      value: value,
      groupValue: groupValue,
      onChanged: onChanged,
      toggleable: toggleable,
      activeColor: activeColor,
      materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
      autofocus: autofocus,
    );
    Widget leading, trailing;
    switch (controlAffinity) {
      case ListTileControlAffinity.leading:
      case ListTileControlAffinity.platform:
        leading = control;
        trailing = secondary;
        break;
      case ListTileControlAffinity.trailing:
        leading = secondary;
        trailing = control;
        break;
    }
    return MergeSemantics(
      child: ListTileTheme.merge(
        selectedColor: activeColor ?? Theme.of(context).accentColor,
        child: ListTile(
          leading: leading,
          title: title,
          subtitle: subtitle,
          trailing: trailing,
          horizontalTitleGap:0,//和源码的区别就是加了一个这个
          isThreeLine: isThreeLine,
          dense: dense,
          enabled: onChanged != null,
          shape: shape,
          tileColor: tileColor,
          selectedTileColor: selectedTileColor,
          onTap: onChanged != null ? () {
            if (toggleable && checked) {
              onChanged(null);
              return;
            }
            if (!checked) {
              onChanged(value);
            }
          } : null,
          selected: selected,
          autofocus: autofocus,
          contentPadding: contentPadding,
        ),
      ),
    );
  }
}