https://github.com/quire-io/scroll-to-index

scroll to index with fixed/variable row height inside Flutter scrollable widget
https://github.com/quire-io/scroll-to-index

Last synced: 3 months ago
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scroll to index with fixed/variable row height inside Flutter scrollable widget

• Host: GitHub
• URL: https://github.com/quire-io/scroll-to-index
• Owner: quire-io
• License: mit
• Created: 2019-04-24T03:41:14.000Z (almost 6 years ago)
• Default Branch: master
• Last Pushed: 2024-06-04T19:03:30.000Z (8 months ago)
• Last Synced: 2024-07-31T15:01:38.534Z (6 months ago)
• Language: Dart
• Homepage:
• Size: 87.9 KB
• Stars: 503
• Watchers: 16
• Forks: 102
• Open Issues: 26
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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• awesome-flutter - Scroll To Index - scroll to index with fixed/variable row height inside Flutter scrollable widget ` 📝 4 months ago` (UI [🔝](#readme))
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README

        
# scroll-to-index

This package provides the scroll to index mechanism for fixed/variable row height for Flutter scrollable widget.

## Getting Started

In the `pubspec.yaml` of your flutter project, add the following dependency:

```yaml

dependencies:

  ...

  scroll_to_index: any

```

In your library add the following import:

```dart

import 'package:scroll_to_index/scroll_to_index.dart';

```

For help getting started with Flutter, view the online [documentation](https://flutter.io/).

## Usage

This is a widget level library, means you can use this mechanism inside any Flutter scrollable widget.

Example for Flutter ListView

``` dart

ListView(

  scrollDirection: scrollDirection,

  controller: controller,

  children: randomList.map((data) {

  	final index = data[0];

  	final height = data[1];

    return AutoScrollTag(

      key: ValueKey(index),

      controller: controller,

      index: index,

      child: Text('index: $index, height: $height'),

      highlightColor: Colors.black.withOpacity(0.1),

    );

  }).toList(),

)

```

you can wrap any of your row widget which has dynamic row height

``` dart

AutoScrollTag(

  key: ValueKey(index),

  controller: controller,

  index: index,

  child: child

)

```

with the `AutoScrollController` controller.

when you need to trigger scroll to a specified index, you can call

```

controller.scrollToIndex(index, preferPosition: AutoScrollPosition.begin)

```

even more, with a fixed row height, you can give it a suggested height for more efficient scrolling. there are more configuration.

```

final controller = AutoScrollController(

  //add this for advanced viewport boundary. e.g. SafeArea

  viewportBoundaryGetter: () => Rect.fromLTRB(0, 0, 0, MediaQuery.of(context).padding.bottom),

  //choose vertical/horizontal

  axis: scrollDirection,

  //this given value will bring the scroll offset to the nearest position in fixed row height case.

  //for variable row height case, you can still set the average height, it will try to get to the relatively closer offset 

  //and then start searching.

  suggestedRowHeight: 200

);

```

for full example, please see this [Demo](https://github.com/quire-io/scroll-to-index/blob/master/example/lib/main.dart).

## Who Uses

* [Quire](https://quire.io) - a simple, collaborative, multi-level task management tool.