Getting errors on using Flutter New Gradient App Bar Package

Question

I would like to use New Gradient App Bar package text on my app using the code below. I used this code before on the past version of flutter and got no problem.

      appBar: PreferredSize(
        preferredSize: const Size(85,85), // here the desired height
        child: NewGradientAppBar(
          title: const Text(
            'Project',
            style: TextStyle(
              fontStyle: FontStyle.italic,
              letterSpacing: 0.1,
              fontWeight: FontWeight.w800,
              fontFamily: 'Roboto',
              height: 1.3,
              fontSize: 50,
            ),
            textAlign: TextAlign.center,
          ),
          gradient: LinearGradient(colors: [Colors.teal.shade300, Colors.teal, Colors.teal.shade800]),

but I'm getting errors on the console when I run the project which are below.

Running Gradle task 'assembleDebug'... ../../AppData/Local/Pub/Cache/hosted/pub.dev/new_gradient_app_bar-0.2.0/lib/new_gradient_app_bar.dart:422:21: Error: The getter 'textTheme' isn't defined for the class 'AppBarTheme'.

'AppBarTheme' is from 'package:flutter/src/material/app_bar_theme.dart' ('/C:/flutter/packages/flutter/lib/src/material/app_bar_theme.dart'). Try correcting the name to the name of an existing getter, or defining a getter or field named 'textTheme'. appBarTheme.textTheme?.headline6 ?? ^^^^^^^^^ ../../AppData/Local/Pub/Cache/hosted/pub.dev/new_gradient_app_bar-0.2.0/lib/new_gradient_app_bar.dart:425:21: Error: The getter 'textTheme' isn't defined for the class 'AppBarTheme'.

'AppBarTheme' is from 'package:flutter/src/material/app_bar_theme.dart' ('/C:/flutter/packages/flutter/lib/src/material/app_bar_theme.dart'). Try correcting the name to the name of an existing getter, or defining a getter or field named 'textTheme'. appBarTheme.textTheme?.bodyText2 ?? ^^^^^^^^^ ../../AppData/Local/Pub/Cache/hosted/pub.dev/new_gradient_app_bar-0.2.0/lib/new_gradient_app_bar.dart:580:21: Error: The getter 'brightness' isn't defined for the class 'AppBarTheme'.

'AppBarTheme' is from 'package:flutter/src/material/app_bar_theme.dart' ('/C:/flutter/packages/flutter/lib/src/material/app_bar_theme.dart'). Try correcting the name to the name of an existing getter, or defining a getter or field named 'brightness'. appBarTheme.brightness ?? ^^^^^^^^^^ ../../AppData/Local/Pub/Cache/hosted/pub.dev/new_gradient_app_bar-0.2.0/lib/new_gradient_app_bar.dart:581:19: Error: The getter 'primaryColorBrightness' isn't defined for the class 'ThemeData'.

'ThemeData' is from 'package:flutter/src/material/theme_data.dart' ('/C:/flutter/packages/flutter/lib/src/material/theme_data.dart'). Try correcting the name to the name of an existing getter, or defining a getter or field named 'primaryColorBrightness'. themeData.primaryColorBrightness; ^^^^^^^^^^^^^^^^^^^^^^ ../../AppData/Local/Pub/Cache/hosted/pub.dev/new_gradient_app_bar-0.2.0/lib/new_gradient_app_bar.dart:591:32: Error: The getter 'color' isn't defined for the class 'AppBarTheme'.

'AppBarTheme' is from 'package:flutter/src/material/app_bar_theme.dart' ('/C:/flutter/packages/flutter/lib/src/material/app_bar_theme.dart'). Try correcting the name to the name of an existing getter, or defining a getter or field named 'color'. color: appBarTheme.color ?? themeData.primaryColor, ^^^^^ Target kernel_snapshot failed: Exception

FAILURE: Build failed with an exception.

What went wrong: Execution failed for task ':app:compileFlutterBuildDebug'.

Process 'command 'C:\flutter\bin\flutter.bat'' finished with non-zero exit value 1

Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

I tried to Pub get and Pub Upgrade hoping it is a dependencies issue but still the errors doesn't still there.

Answer 1

This package is no longer maintained. However since it is UI only you yourself can take a fork and correct it.

But there is already a repo where this has been done and you can refer it. https://github.com/GUIKAR741/NewGradientAppBar

using

  new_gradient_app_bar:
    git: https://github.com/GUIKAR741/NewGradientAppBar.git