Classes and objects in Flutter - UI Render Trace

Component - Classes and objects

This Flutter component demonstrates how to use classes and objects by creating a simple Person class and displaying its properties on the screen. It shows how to define a class, create an object, and use its data in the UI.

Widget Tree

Scaffold
├─ AppBar
│  └─ Text
└─ Center
   └─ Column
      ├─ Text (Name)
      └─ Text (Age)

The Scaffold provides the basic app structure with an AppBar at the top showing the title. The body centers a Column that contains two Text widgets displaying the person's name and age.

Render Trace - 5 Steps

Step 1: Scaffold

Step 2: Center

Step 3: Column

Step 4: Text (Name)

Step 5: Text (Age)

State Change - Re-render

Trigger:No state change in this simple example; the Person object is created once

Before

No Person object created, screen empty except app bar

→

After

Person object created with name 'Alice' and age 30; UI shows these values

Re-renders:Entire Scaffold body renders once with the Person data

UI Quiz - 3 Questions

What widget centers the name and age text on the screen?

A Center

B Column

C Scaffold

D AppBar

Key Insight

In Flutter, classes let you organize data and behavior together. You create an object from a class and use its properties to show dynamic content in your UI. Widgets like Column and Center help arrange this content clearly and attractively.