CODE EXAMPLE FOR SWIFT

flutter component: custom appbar

import 'package:flutter/material.dart';

class CustomAppBar extends StatelessWidget implements PreferredSizeWidget {
  final String? title;
  final Color? titleColor;
  final Color? backgroundColor;
  final Icon? leftIcon;
  final bool? isShowLeftIcon;
  final bool? isShowActionIcon1;
  final bool? isShowActionIcon2;
  final bool? isShowActionIcon3;
  final Icon? actionIcon1;
  final Icon? actionIcon2;
  final Icon? actionIcon3;
  final VoidCallback? pressedLeftIcon;
  final VoidCallback? pressedActionIcon1;
  final VoidCallback? pressedActionIcon2;
  final VoidCallback? pressedActionIcon3;

  const CustomAppBar({
    Key? key,
    this.title = "",
    this.titleColor,
    this.backgroundColor,
    this.leftIcon,
    this.isShowLeftIcon = false,
    this.isShowActionIcon1 = false,
    this.isShowActionIcon2 = false,
    this.isShowActionIcon3 = false,
    this.actionIcon1 = const Icon(Icons.search),
    this.actionIcon2 = const Icon(Icons.alarm),
    this.actionIcon3 = const Icon(Icons.airline_seat_flat),
    this.pressedLeftIcon,
    this.pressedActionIcon1,
    this.pressedActionIcon2,
    this.pressedActionIcon3,
  }) : super(key: key);

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

  @override
  Widget build(BuildContext context) {
    return AppBar(
      // centerTitle: true,
      title: Text(
        title!,
        style: TextStyle(
          color: titleColor,
        ),
      ),
      backgroundColor: backgroundColor,
      elevation: 0,
      leading: isShowLeftIcon!
          ? IconButton(
              icon: leftIcon!,
              onPressed: pressedLeftIcon,
            )
          : const Offstage(),
      actions: [
        Visibility(
          visible: isShowActionIcon1!,
          child: IconButton(
            icon: actionIcon1!,
            onPressed: pressedActionIcon1,
          ),
        ),
        Visibility(
          visible: isShowActionIcon2!,
          child: IconButton(
            icon: actionIcon2!,
            onPressed: pressedActionIcon2,
          ),
        ),
        Visibility(
          visible: isShowActionIcon3!,
          child: IconButton(
            icon: actionIcon3!,
            onPressed: pressedActionIcon3,
          ),
        )
      ],
    );
  }
}


// Widget : use this class in :::  appBar: ...

class CAB extends StatelessWidget implements PreferredSizeWidget {
  const CAB({
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const CustomAppBar(
      title: "Flutter Demo",
      isShowLeftIcon: true,
      leftIcon: Icon(
        Icons.chevron_left_outlined,
        color: Colors.white,
      ),
      isShowActionIcon1: true,
      actionIcon1: Icon(
        Icons.category,
        color: Colors.white,
      ),
      isShowActionIcon2: true,
      actionIcon2: Icon(Icons.air_rounded, color: Colors.white,),
      isShowActionIcon3: true,
      actionIcon3: Icon(Icons.search, color: Colors.white,),
    );
  }
  
  @override
  Size get preferredSize => const Size.fromHeight(kToolbarHeight);
}