Introduction

Flutter, an open-source UI framework developed by Google has revolutionized the world of app development for its declarative and dynamic approach to developing user interfaces. In the heart of Flutter’s development rests its original widget system. In this blog, we will take a tour of the Flutter widget tree and cover everything from basic widgets to what they are all about and how you can create your own custom ones for your app.

Understanding Widgets in Flutter

The use of widgets is that in Flutter everything on the screen you see, is in fact a widget. It is represented with the help of a widget as whether it’s a button, text field, image or even structure of entire app.

Widgets in Flutter are categorized into two main types:

1. Stateless Widgets:

The greatest strength derived from using stateless widgets is the immutability which means that they do not change over time. They stand for elements of the user interface that never change, e. You can create stateless widgets using the StatelessWidget class and they describe only how a part of your UI looks like.
Here’s an example of a simple stateless widget:

dartCopy codeclass MyTextWidget extends StatelessWidget {

  final String text;



  MyTextWidget(this.text);



  @override

  Widget build(BuildContext context) {

    return Text(text);

  }

}

2. Stateful Widgets:

Stateful widgets, on the other hand, are mutable and can change over time. They are used to represent parts of the UI that can be interactive or dynamic, such as forms, animated elements, or real-time data. Stateful widgets are created using the StatefulWidget class and maintain a separate mutable state object.

Here’s an example of a simple stateful widget:

dartCopy codeclass MyCounterWidget extends StatefulWidget {

  @override

  _MyCounterWidgetState createState() => _MyCounterWidgetState();

}



class _MyCounterWidgetState extends State<MyCounterWidget> {

  int count = 0;



  void incrementCounter() {

    setState(() {

      count++;

    });

  }



  @override

  Widget build(BuildContext context) {

    return Column(

      children: <Widget>[

        Text('Counter: $count'),

        ElevatedButton(

          onPressed: incrementCounter,

          child: Text('Increment'),

        ),

      ],

    );

  }

}

The Widget Tree

In Flutter, widgets are structured in a widget tree. MaterialApp is the root of the tree; this is the widget that describes the structure of the application you are building. It is this widget tree that establishes the visual structure of your app and defines how widgets are put together on a screen.

Widgets can possess children that are widgets too. The Flutter framework takes the entire widget tree and renders it as the ultimate user interface. The widget tree is the most important reason for constructing a compound and adaptable approach of forming layouts.

Creating Custom Widgets

One of the strongest aspects of Flutter is widget creation, as you can develop your own custom widgets that will be included in the code and could represent some special part of your UI. The use of custom widgets also encourages code reusability which makes your codebase structure more manageable.

Creating widgets that are of interest to us is done by creating a class and then extending either StatelessWidget or StatelessWidget and implementing the build method in them. Another ability of custom widgets is you are able specify parameters (properties) for it, to make the behavior or design customizable.

Here’s a simple example of a custom widget:

dartCopy codeclass MyCustomButton extends StatelessWidget {

  final String label;

  final Function onPressed;



  MyCustomButton({required this.label, required this.onPressed});



  @override

  Widget build(BuildContext context) {

    return ElevatedButton(

      onPressed: () => onPressed(),

      child: Text(label),

    );

  }

}

In this case, we have developed a widget for a custom button which accepts a callback. With the help of this widget, you can make buttons by giving them different titles and different tasks to perform.

Conclusion

Flutter’s widget system is the unit of change for your app’s UI. In Flutter development, this should conclude the understanding of how widgets work, distinguishing stateless and stateful widgets and creating custom widgets. In the course of your continued journey within the Flutter framework, you will find out how flexible, and expressive it is when creating wonderfully designed user interfaces or animations. Happy widget building!