In some scenarios, you might want to prevent users from scrolling a list view using their touch screen. There are several valid reasons for this approach, such as optimizing performance or ensuring certain UI elements remain accessible.
In Flutter, the default behavior of a list view allows users to scroll through its content with ease. However, if you need to disable this functionality while still allowing scrolling via other means (like horizontal dragging on desktop), you’re in luck! There’s a built-in solution that achieves exactly what you need: the NeverScrollableScrollPhysics class.
The Solution: NeverScrollableScrollPhysics
NeverScrollableScrollPhysics is a scroll physics class provided by Flutter specifically designed to prevent scrolling when used within a list view. The intention behind its creation was to provide developers with an easy way to disable scrolling without affecting the overall UI experience.
How to Use NeverScrollableScrollPhysics in Your ListView
To use this feature, you’ll need to modify your list view’s properties by adding the physics parameter. The following code snippet shows exactly how you can implement this:
ListView( // Other properties... physics: const NeverScrollableScrollPhysics(), children: // Your list of items here, )
Here, we’ve applied NeverScrollableScrollPhysics to our list view using the `physics` parameter. The `const` keyword is used because we’re not modifying this instance; it’s a constant value.
Example Code for ListView Disable Scrolling with Touchscreen
import 'package:flutter/material.dart'; class MyListWidget extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('Never Scrollable List View'), ), body: ListView( physics: const NeverScrollableScrollPhysics(), shrinkWrap: true, children:[ ListTile(title: Text('Item 1')), ListTile(title: Text('Item 2')), ListTile(title: Text('Item 3')), // Add more list items here... ], ), ); } }
This code creates a simple list view within a Material design Scaffold. Notice how we’ve used NeverScrollableScrollPhysics to prevent scrolling on our list view, ensuring users cannot scroll the content.
Conclusion
In this article, you’ve learned about the NeverScrollableScrollPhysics class and how it can be applied to your ListView widget in Flutter to disable scrolling with a touchscreen. This approach is invaluable for scenarios where optimizing performance or maintaining accessibility are crucial concerns.
The process of implementing NeverScrollableScrollPhysics into your code snippet has been explained in detail, along with an example use case that demonstrates its effectiveness in real-world scenarios.