List JsInterface over JsArray

js_list.dart

import 'dart:collection';
import 'package:js/js.dart';


abstract class JsList<E> extends JsInterface with ListMixin<E> {
  JsObject _js;

  factory JsList() => new JsListImpl();
  JsList.created(JsObject o) : _js = o, super.created(o);

  // method to implement for ListMixin

  @override int get length => _js['length'];
  @override void set length(int length) { _js['length'] = length; }
  @override E operator [](index) {
    if (index is int && (index < 0 || index >= this.length)) {
      throw new RangeError.value(index);
    }
    return toDart(_js[index]);
  }
  @override void operator []=(int index, E value) {
    if (index < 0 || index >= this.length) {
      throw new RangeError.value(index);
    }
    _js[index] = toJs(value);
  }

  // overriden methods for better performance

  @override void add(E value) { _js.callMethod('push', [toJs(value)]); }
  @override void addAll(Iterable<E> iterable) {
    _js.callMethod('push', iterable.map(toJs).toList());
  }
  @override void sort([int compare(E a, E b)]) {
    final sortedList = toList()..sort(compare);
    setRange(0, sortedList.length, sortedList);
  }
  @override void insert(int index, E element) {
    _js.callMethod('splice', [index, 0, toJs(element)]);
  }
  @override E removeAt(int index) {
    if (index < 0 || index >= this.length) throw new RangeError.value(index);
    return toDart(_js.callMethod('splice', [index, 1])[0]);
  }
  @override E removeLast() => toDart(_js.callMethod('pop'));
  @override void setRange(int start, int length, List<E> from,
                          [int startFrom = 0]) {
    final args = [start, length];
    for(int i = startFrom; i < startFrom + length; i++) {
      args.add(toJs(from[i]));
    }
    _js.callMethod('splice', args);
  }
  @override void removeRange(int start, int end) {
    _js.callMethod('splice', [start, end - start]);
  }
}

@JsProxy(constructor: 'Array')
class JsListImpl extends JsList {
  factory JsListImpl() => new JsInterface(JsListImpl, []);
  JsListImpl.created(JsObject o) : super.created(o);
  noSuchMethod(i) => super.noSuchMethod(i);
}