Needs to call some custom logic when the user reaches the end of the scroll? ScrollEdgeListener is specifically designed to be used for implementing infinite scroll pagination with a lot of flexibility and cool semantics. Just set the listener and offset property and enjoy it.

Getting started

edge

The edge property can be set to one of ScrollEdge.start and ScrollEdge.end. It determines on which side of the edge will call the listener.

Defaults to ScrollEdge.end.

edgeOffset

The offset from the edge. Useful when you want to trigger the listener before the user reaches the start or end of the scroll.

Defaults to 0.

continuous

If true, the listener will be continuously called if the scroll position is in the offset. If false, the listener will only be called once it reaches the offset everytime.

Defaults to false.

debounce

The debounce time for the listener.

Defaults to Duration.zero.

dispatch

Determines whether it should propagate the notification event or not.

Defaults to true.

Usage

This widget is designed to be used for implementing infinite scroll pagination. Set the offset and call the listener before the user reaches the end of the scroll and load the content ahead. The content will be loaded faster than it was because you loaded it before it reaches the end. Also, continuous and debounce prevents multiple calls in a short period of time.

ScrollEdgeListener(
  edge: ScrollEdge.end,
  edgeOffset: 400,
  continuous: false,
  debounce: const Duration(milliseconds: 500),
  dispatch: true,
  listener: () {
    debugPrint('listener called');
  },
  child: ListView(
    children: const [
      Placeholder(),
      Placeholder(),
      Placeholder(),
      Placeholder(),
    ],
  ),
),

Libraries

scroll_edge_listener