Scroll Preload Detector

A Flutter widget designed to enhance user experience that listens to scroll notifications and triggers a preload callback when the user scrolls near the end of the content. This is a crucial component for implementing robust infinite scrolling or lazy loading patterns in your Flutter applications.

Features

• 🚀 Performance First: Built on NotificationListener, avoiding expensive build cycles.
• 🎯 Precise Control: Configure preloadDistance to trigger loading exactly when needed.
• 🔄 Smart Debouncing: Prevents multiple load triggers while a request is already in progress.
• 🎛 Flexible Configuration: Supports custom scroll directions (scrollDirection) and specific axes (axisDirection).
• 🛡 Control Flags: Easily enable/disable detection or check hasMore data condition.

Preview

Enable Preload	Disable Preload

Getting started

Add this to your package's pubspec.yaml file:

dependencies:
  scroll_preload_detector: ^0.0.1

Usage

Wrap your ScrollView (like ListView, GridView, or CustomScrollView) with ScrollPreloadDetector.

import 'package:scroll_preload_detector/scroll_preload_detector.dart';

ScrollPreloadDetector(
  // Trigger loading when 600 pixels from the end
  preloadDistance: 600.0,
  
  // Your data loading logic
  preload: () async {
    await fetchMoreData();
  },
  
  // Check if there is more data to load to prevent unnecessary callbacks
  hasMore: () => hasMoreData,
  
  child: ListView.builder(
    itemCount: items.length,
    itemBuilder: (context, index) {
      return ListTile(title: Text('Item $index'));
    },
  ),
)

Additional information

This package is designed to be lightweight and non-intrusive. It doesn't modify your ScrollView's physics or controller, making it compatible with other scroll libraries.