Navigator.push and pop in Flutter - UI Render Trace

Component - Navigator.push and pop

This UI component demonstrates how to move between two screens in a Flutter app using Navigator.push to go forward and Navigator.pop to go back. It mimics real-life situations like moving from a home screen to a details screen and then returning.

Widget Tree

Scaffold
├─ AppBar
│  └─ Text("Home Screen")
├─ Center
│  └─ ElevatedButton("Go to Details")

DetailsScreen Scaffold
├─ AppBar
│  └─ Text("Details Screen")
├─ Center
│  └─ ElevatedButton("Go Back")

The main screen uses a Scaffold with an AppBar showing 'Home Screen' and a centered button labeled 'Go to Details'. When pressed, it navigates to the DetailsScreen, which also has a Scaffold with an AppBar titled 'Details Screen' and a centered button labeled 'Go Back' to return.

Render Trace - 6 Steps

Step 1: Scaffold (Home Screen)

Step 2: ElevatedButton (Home Screen)

Step 3: Navigator.push

Step 4: Scaffold (Details Screen)

Step 5: ElevatedButton (Details Screen)

Step 6: Navigator.pop

State Change - Re-render

Trigger:User taps 'Go to Details' button, then taps 'Go Back' button

Before

Only Home Screen is visible

→

After

Details Screen is shown after push, then Home Screen is shown again after pop

Re-renders:Entire screen subtree of the pushed or popped screen re-renders

UI Quiz - 3 Questions

What happens when the 'Go to Details' button is pressed?

A The button changes its label

B The app closes

C The app navigates to the Details Screen using Navigator.push

D Nothing happens

Key Insight

Using Navigator.push and Navigator.pop lets users move forward and backward between screens, just like flipping pages in a book. This keeps navigation simple and intuitive in mobile apps.