Kavantix

import 'dart:async';
import 'dart:isolate';

Future<R> compute<I, R>(R Function(I) f, I input,
    {String debugName = ''}) async {
  final resultPort = ReceivePort();
  final args = _ComputeArgs<I, R>(resultPort.sendPort, f, input);
  final isolate = await Isolate.spawn<_ComputeArgs<I, R>>(
    _compute,
    args,

Kavantix

import 'dart:collection';

abstract class MappedListView<T, R> implements List<R> {
  factory MappedListView(
    List<T> wrapped,
    R Function(T element) mapper,
  ) = _MappedListView<T, R>;
}

class _MappedListView<T, R> with ListMixin<R> implements List<R>, MappedListView<T, R> {

Kavantix

class LimitingScrollPhysics extends PageScrollPhysics {
  LimitingScrollPhysics({ScrollPhysics parent, @required this.controller})
      : super(parent: parent);

  final ScrollController controller;

  @override
  LimitingScrollPhysics applyTo(ScrollPhysics ancestor) {
    return LimitingScrollPhysics(
        parent: buildParent(ancestor), controller: controller);

Kavantix

class PageAlignedScrollPhysics extends ScrollPhysics {
  final double pageSize;

  PageAlignedScrollPhysics({@required this.pageSize, ScrollPhysics parent}) : super(parent: parent);

  @override
  PageAlignedScrollPhysics applyTo(ScrollPhysics ancestor) {
    return PageAlignedScrollPhysics(pageSize: pageSize, parent: buildParent(ancestor));
  }