aku_new_community/lib/pages/home/widget/animate_app_bar.dart

import 'package:aku_new_community/provider/app_provider.dart';
import 'package:aku_new_community/utils/headers.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:provider/provider.dart';

class AnimateAppBar extends StatefulWidget with PreferredSizeWidget {
  final ScrollController? scrollController;
  final List<Widget>? actions;

  AnimateAppBar({Key? key, this.scrollController, this.actions})
      : super(key: key);

  @override
  _AnimateAppBarState createState() => _AnimateAppBarState();

  @override
  Size get preferredSize => Size.fromHeight(45);
}

class _AnimateAppBarState extends State<AnimateAppBar> {
  Color _bgColor = Colors.white;

  @override
  void initState() {
    super.initState();
    widget.scrollController!.addListener(() {
      setState(() {
        _bgColor = widget.scrollController!.offset > 30
            ? Colors.white
            : widget.scrollController!.offset < 0
                ? Colors.transparent
                : Colors.white
                    .withOpacity((widget.scrollController!.offset / 30));
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    final appProvider = Provider.of<AppProvider>(context);
    return Padding(
      padding: const EdgeInsets.only(top: 5),
      child: AppBar(
        titleSpacing: 10.0,
        title: Row(crossAxisAlignment: CrossAxisAlignment.center, children: [
          if (appProvider.location != null)
            Padding(
              padding: const EdgeInsets.only(right: 5),
              child: Image.asset(
                R.ASSETS_ICONS_ICON_MAIN_LOCATION_PNG,
                width: 32.w,
                height: 32.w,
              ),
            ),
          Text(
            appProvider.location?['city'] == null
                ? ''
                : appProvider.location?['city'] as String? ?? '',
            style: TextStyle(
              fontWeight: FontWeight.w600,
              fontSize: 24.sp,
              color: Color(0xff333333),
            ),
            textAlign: TextAlign.center,
          ),
          Text(
            '(${appProvider.weatherType} ${appProvider.weatherTemp}℃)',
            style: TextStyle(
              fontSize: 24.sp,
              color: Color(0xff999999),
            ),
            textAlign: TextAlign.center,
          ),
        ]),
        backgroundColor: _bgColor,
        actions: widget.actions,
      ),
    );
  }
}