import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:keyboard_actions/keyboard_actions.dart';
import 'package:keyboard_actions/keyboard_actions_config.dart';

/// 本项目通用的布局（SingleChildScrollView）
/// 1.底部存在按钮
/// 2.底部没有按钮
class MyScrollView extends StatelessWidget {

  /// 注意：同时存在底部按钮与keyboardConfig配置时，为保证软键盘弹出高度正常。需要在`Scaffold`使用 `resizeToAvoidBottomInset: defaultTargetPlatform != TargetPlatform.iOS,`
  /// 除非Android与iOS平台均使用keyboard_actions
  const MyScrollView({
    Key? key,
    required this.children,
    this.padding,
    this.physics = const BouncingScrollPhysics(),
    this.crossAxisAlignment = CrossAxisAlignment.start,
    this.bottomButton,
    this.keyboardConfig,
    this.tapOutsideToDismiss = false,
    this.overScroll = 16.0,
  }): super(key: key);

  final List<Widget> children;
  final EdgeInsetsGeometry? padding;
  final ScrollPhysics physics;
  final CrossAxisAlignment crossAxisAlignment;
  final Widget? bottomButton;
  final KeyboardActionsConfig? keyboardConfig;
  /// 键盘外部按下将其关闭
  final bool tapOutsideToDismiss;
  /// 默认弹起位置在TextField的文字下面，可以添加此属性继续向上滑动一段距离。用来露出完整的TextField。
  final double overScroll;

  @override
  Widget build(BuildContext context) {

    Widget contents = Column(
      crossAxisAlignment: crossAxisAlignment,
      children: children,
    );

    if (defaultTargetPlatform == TargetPlatform.iOS && keyboardConfig != null) {
      /// iOS 键盘处理

      if (padding != null) {
        contents = Padding(
          padding: padding!,
          child: contents
        );
      }

      contents = KeyboardActions(
        isDialog: bottomButton != null,
        overscroll: overScroll,
        config: keyboardConfig!,
        tapOutsideBehavior: tapOutsideToDismiss ? TapOutsideBehavior.opaqueDismiss : TapOutsideBehavior.none,
        child: contents
      );

    } else {
      contents = SingleChildScrollView(
        padding: padding,
        physics: physics,
        child: contents,
      );
    }

    if (bottomButton != null) {
      contents = Column(
        children: <Widget>[
          Expanded(
            child: contents
          ),
          SafeArea(
            child: bottomButton!
          )
        ],
      );
    }

    return contents;
  }
}