Make sure wait until build context is ready

To ensure that you only execute certain code when the build context is fully ready, you can make use of the WidgetsBinding.instance.addPostFrameCallback method. This method schedules a callback that will be executed after the current frame is drawn, ensuring that the build context is fully initialized and mounted.

Here’s an example of how you can use it:

import 'package:flutter/material.dart';

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) {
        // Your code here that depends on the context being fully built
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Example'),
      ),
      body: Center(
        child: Text('Hello, World!'),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: MyWidget(),
  ));
}

In this example, the WidgetsBinding.instance.addPostFrameCallback ensures that the provided callback is executed only after the build method has completed and the widget is mounted. The if (mounted) check within the callback ensures that the code runs only if the widget is still part of the widget tree, preventing potential errors if the widget is disposed of before the callback is executed.

This approach is useful for scenarios where you need to interact with the build context, such as showing dialogs, accessing inherited widgets, or performing layout-related computations, and you want to ensure that the widget is fully built and mounted before doing so.