I want your opinion, I will try to explain. I have a home.dart page that includes an appbar widget that I'm looking for in a file called fc_commun.dart. In fc_commun.dart I'm going to put the functions common to all my pages, and I have for example a function that retrieves the dimensions of the screen (recupdimensionecran) but for example, I want to use this function in my showdialogue of my appbar and also in my home.dart, common do?

home.dart

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

import 'fc_commun.dart';

class Homepage extends StatefulWidget {
  const Homepage({Key? key}) : super(key: key);
  @override
  _HomepageState createState() => _HomepageState();
}

class _HomepageState extends State<Homepage> {
  Color mainColor = const Color(0xff3366FF);
  @override
  Widget build(BuildContext context) {
    SystemChrome.setPreferredOrientations([
      DeviceOrientation.portraitUp,
      DeviceOrientation.portraitDown,
    ]);

    recupdimensionecran(context);
//var test = heightmobile;

    return Scaffold(
      resizeToAvoidBottomInset: false,
      backgroundColor: Colors.transparent,
      appBar: const Appbarjeu(),
      body: Container(
        alignment: Alignment.topCenter,
        decoration: BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
            colors: [
              Colors.black,
              mainColor,
              Colors.black,
            ],
          ),
        ),
        child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: const [
              Text("Test Texte"),
            ]),
      ),
    );
  }
}

fc_commun.dart

import 'package:flutter/material.dart';

void recupdimensionecran(BuildContext context) {
  double heightmobile = MediaQuery.of(context).size.height;
  double widthmobile = MediaQuery.of(context).size.width;
}

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

  @override
  Size get preferredSize => const Size.fromHeight(100);

  @override
  Widget build(BuildContext context) {
    return AppBar(
      title: Row(mainAxisAlignment: MainAxisAlignment.center, children: const [
        Text(
          'My',
          style: TextStyle(
            fontSize: 40,
            fontWeight: FontWeight.w900,
            color: Color(0xff3366FF),
          ),
        ),
        SizedBox(width: 10),
        Text(
          'Appi',
          style: TextStyle(
              fontSize: 40, fontWeight: FontWeight.w900, color: Colors.white),
        ),
        SizedBox(width: 10),
        Text(
          '!',
          style: TextStyle(
              fontSize: 40,
              fontWeight: FontWeight.w900,
              color: Color(0xff3366FF)),
        )
      ]),
      backgroundColor: Colors.transparent,
      elevation: 0.0,
      actions: <Widget>[
        IconButton(
          icon: const Icon(
            Icons.settings,
            color: Colors.white,
          ),
          onPressed: () {
            _buildPopupDialog(context);
          },
        )
      ],
    );
  }

  void _buildPopupDialog(BuildContext context) {
    showDialog(
        context: context,
        builder: (context) {
          return AlertDialog(
            title: Container(),
            content: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: <Widget>[
                Container(
                  padding: const EdgeInsets.all(5.0),
                  child: Align(
                    alignment: Alignment.topLeft,
                    child: Column(
                      children: const <Widget>[
                        Text(
                          'Show dialogue :',
                          textAlign: TextAlign.left,
                          style: TextStyle(
                            decoration: TextDecoration.underline,
                            color: Colors.red,
                            fontWeight: FontWeight.bold,
                            fontSize: 14,
                          ),
                        ),
                        Text(
                          '  Test',
                          textAlign: TextAlign.left,
                          style: TextStyle(
                            color: Colors.red,
                            fontWeight: FontWeight.bold,
                            fontSize: 14,
                          ),
                        ),
                      ],
                    ),
                  ),
                )
              ],
            ),
            actions: <Widget>[
              // ignore: unnecessary_new
              ElevatedButton(
                child: const Text(
                  "X",
                  style: TextStyle(fontSize: 24),
                ),
                onPressed: () {
                  Navigator.of(context).pop();
                },
                style: ElevatedButton.styleFrom(
                  shape: const CircleBorder(),
                ),
              ),
            ],
          );
        });
  }
}

Thank you

CodePudding user response：

Widget customCircularIcon(Color bgcolor, Color iconColor, IconData icon,
    {double size: 22}) {
  return Padding(
    padding: const EdgeInsets.only(right: 8),
    child: Container(
      decoration: BoxDecoration(color: bgcolor, shape: BoxShape.circle),
      child: Padding(
        padding: const EdgeInsets.all(6.0),
        child: Center(
          child: FaIcon(
            icon,
            size: size,
            color: iconColor,
            // size: 40,
            // color: Colors.white,
          ),
        ),
      ),
    ),
  );
}

This is just a widget, whenever you want you can place it....or you can create a class as well to achieve the same.