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

class CustomAppBarWidget extends StatelessWidget implements PreferredSizeWidget {
  final String title;
  final List<Widget>? actions;
  final Widget? leading;
  final bool centerTitle;
  final Color? backgroundColor;
  final double? elevation;

  const CustomAppBarWidget({
    super.key,
    required this.title,
    this.actions,
    this.leading,
    this.centerTitle = true,
    this.backgroundColor = Colors.white,
    this.elevation,
  });

  @override
  Widget build(BuildContext context) {
    // 判断是否需要显示返回按钮
    bool showBackButton = ModalRoute.of(context)?.canPop ?? false;
    return AppBar(
      title: Text(
        title,
        style: TextStyle(
          fontSize: 18.sp,
          fontWeight: FontWeight.w500,
        ),
      ),
      actions: actions,
      // 根据是否有自定义leading来决定使用什么
      leading: leading ??
          (showBackButton
              ? IconButton(
                  icon: const Icon(Icons.arrow_back_ios_new_rounded),
                  onPressed: () => Navigator.of(context).pop(),
                )
              : null),
      // 当有leading时标题默认左对齐，否则按centerTitle参数决定
      centerTitle: false,
      backgroundColor: backgroundColor,
      elevation: elevation,
    );
  }

  @override
  Size get preferredSize => const Size.fromHeight(kToolbarHeight);
}