4. What is Widget in flutter ? Let’s clear the basics first.

Harshu Incorporation
3 min readJan 21, 2020

If you start learning flutter you might heard that everything in the flutter is a widget. So the first obvious question occurs in your mind is that what is the meaning of widget ?

What is Widget ?

Widget is a description of a part of UI.

  • In flutter, Widget is a way to declare and construct UI.
  • If you are familiar with the Android or iOS development then you might make the immediate connection with the views (on Android) or UIViews (on iOS).
  • But dear just like view, Widget is not just a piece of UI. Widget is a lot more than just structural elements like buttons, text, image, list or slider. A widget might display Something, it might help define design, it might help with layout, it may handle user interaction, etc.
  • For example, Padding is a widget, Margin is a widget, Center is a widget, Layout rows and columns are also widgets.
  • So you can consider that a widget is a blueprint. Flutter uses these blueprints to create views.
  • Here also remember that in flutter everything is a widget. Even your app itself is a widget. 😊

Widget tree

  • If you already have fun with flutter code then you might notice that infinite Parent-Child tree. Yaa I agree, first time it just scares out any beginner, but dear we all passes from the same stage in which you are right now. Just give it some time, do a lot of practice and Just believe, just like others, you can do it as well. 😉
  • Widgets are arranged into a tree of parent and child widget.
  • Widgets are nested inside of each other to form your app.
  • The Entire widget tree forms a layout that you see on the screen.

Types of Widgets

  • Now when we know what is a widget, its time to know how many types of widgets are there.
  • Flutter has a rich set of in-built widgets like text, buttons, slider, lists, layouts, gesture detector, animations, etc. Flutter team works really hard to create a set of widgets that helps you in almost every situation. And they are continuously adding more widgets as developers needs.
  • But apart from built-in widgets, you can create your own widgets according to your needs.
  • Flutter divides widgets into two categories:
  1. Stateless Widgets
  2. Stateful Widgets

Stateless Widgets

  • In simple words, if a widget doesn’t do anything its Stateless Widget. They are static in nature.
  • Stateless widgets don’t store any state. That means they don’t store values that might change.
  • You can also say that stateless widgets are “DATALESS” widgets. As they don’t store any real-time data.
  • For example, if you have a simple Text widget on the screen, but it doesn’t do anything then its Stateless Widget.
  • Icon, IconButton, and Text are an example of stateless widgets.

Stateful Widgets

  • In simple words, if a widget does anything then its Stateful Widget.
  • A Stateful widget is dynamic in nature. That means it can keep track of changes and update the UI based on those changes.
  • The user can interact with a stateful widget. For example, If you press a button and it performs any task its a Stateful Widget, If you are moving a slider and it does anything then its a Stateful Widget, If you swipe item from a list and item gets deleted then that list a Stateful Widget.
  • CheckBox, Radio, Slider, InkWell, Form, and TextField are an example of stateful widgets.

If you are in doubt, then always remember this rule. 😊

  • If a widget changes, it’s a Stateful Widget
  • If a widget is not changing, it’s a Stateless Widget.

So that’s it for Widgets guys. I hope you get clear clearity. But If you have any questions please feel free to ask me. And If I misses something please tell me that, I’ll love to learn from you.

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Harshu Incorporation

Harshu Inc. is a Missionary Tech Company that aims to create solutions via technology for Humanity.