content: import 'dart:io';
  
  import 'package:flutter/material.dart';
  
  import '../themes/color_palette.dart';
  import '../themes/images_gallery.dart';
  
  class PrimaryAppBar extends AppBar {
    PrimaryAppBar({
      @required BuildContext context,
      Function onClickBackButton,
    }) : super(
            iconTheme: IconThemeData(
              color: grey, //change your color here
            ),
            title: Image(
              image: AssetImage(imgLogoSymbol),
              fit: BoxFit.contain,
              height: 30,
            ),
            leading: IconButton(
              icon: Icon(
                Platform.isIOS ? Icons.arrow_back_ios : Icons.arrow_back,
                color: grey,
              ),
              onPressed: () {
                onClickBackButton != null
                    ? onClickBackButton()
                    : Navigator.pop(context);
              },
            ),
            centerTitle: true,
            brightness: Brightness.light,
            backgroundColor: white,
            elevation: 0,
            bottom: PreferredSize(
              preferredSize: Size.fromHeight(0.0),
              child: Container(
                color: grey,
                height: 2,
                alignment: Alignment.center,
              ),
            ),
          );
  }
  