smart_scroller 0.0.1

Smart scroller view with variable height support

Smart Scroller

A Flutter package that provides smart scrolling functionality with variable height support and enhanced scroll controls.

Features

• Variable height item support for accurate scrolling
• Scroll direction tracking and state management
• Smooth scrolling to specific indices
• Custom scroll controller with state notifications
• Extension methods for easy scroll-to-index functionality

Getting started

To use this package, add smart_scroller as a dependency in your pubspec.yaml file.

dependencies:
  smart_scroller: ^0.0.1

Usage

Basic Usage

import 'package:smart_scroller/smart_scroller.dart';

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  final smartController = SmartScrollController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SingleChildScrollView(
        controller: smartController.controller,
        child: Column(
          children: List.generate(100, (index) => ListTile(title: Text('Item $index'))),
        ),
      ),
    );
  }

  @override
  void dispose() {
    smartController.dispose();
    super.dispose();
  }
}

Using Variable Height Support

class VariableHeightExample extends StatefulWidget {
  @override
  _VariableHeightExampleState createState() => _VariableHeightExampleState();
}

class _VariableHeightExampleState extends State<VariableHeightExample> {
  final smartController = SmartScrollController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SingleChildScrollView(
        controller: smartController.controller,
        child: Column(
          children: List.generate(50, (index) {
            return MeasurableWidget(
              index: index,
              onHeightChanged: (height) {
                smartController.setItemHeight(index, height);
              },
              child: Container(
                height: 50 + (index % 3) * 20.0, // Variable heights
                child: ListTile(title: Text('Item $index')),
              ),
            );
          }),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => smartController.scrollToIndex(25),
        child: Icon(Icons.arrow_downward),
      ),
    );
  }

  @override
  void dispose() {
    smartController.dispose();
    super.dispose();
  }
}

Using Scroll State Notifications

class ScrollStateExample extends StatefulWidget {
  @override
  _ScrollStateExampleState createState() => _ScrollStateExampleState();
}

class _ScrollStateExampleState extends State<ScrollStateExample> {
  final smartController = SmartScrollController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: [
          ValueListenableBuilder<ScrollState>(
            valueListenable: smartController.stateNotifier,
            builder: (context, state, child) {
              return Text('Offset: ${state.offset}, Direction: ${state.direction}');
            },
          ),
          Expanded(
            child: SingleChildScrollView(
              controller: smartController.controller,
              child: Column(
                children: List.generate(100, (index) => ListTile(title: Text('Item $index'))),
              ),
            ),
          ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    smartController.dispose();
    super.dispose();
  }
}

Using Extension Methods

// Using the extension on ScrollController
ScrollController controller = ScrollController();

// Scroll to index 10 with item height 50
await controller.scrollToIndex(index: 10, itemHeight: 50.0);

API Reference

• SmartScrollController: Main controller class with variable height support
• ScrollState: Represents the current scroll state (offset and direction)
• ScrollDirectionX: Enum for scroll directions (idle, up, down)
• VariableHeightManager: Manages height information for variable height items
• MeasurableWidget: Widget that measures and reports its height
• ScrollToIndexExtension: Extension methods for ScrollController

See also

• GitHub Repository
• Pub.dev Package