pkgs/objective_c/lib/src/ns_array.dart

// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:collection';

import 'package:ffi/ffi.dart';

import 'internal.dart';
import 'objective_c_bindings_generated.dart';

class NSArrayAdapter with Iterable<ObjCObjectBase> {
  final NSArray array;

  NSArrayAdapter(this.array);

  @override
  int get length => array.count;

  @override
  ObjCObjectBase elementAt(int index) => array.objectAtIndex(index);

  @override
  Iterator<ObjCObjectBase> get iterator => _NSArrayIterator(this);

  ObjCObjectBase operator [](int index) => array.objectAtIndex(index);
}

class NSMutableArrayAdapter with ListBase<ObjCObjectBase> {
  final NSMutableArray array;

  NSMutableArrayAdapter(this.array);

  @override
  int get length => array.count;

  @override
  set length(int newLength) {
    var len = length;
    RangeError.checkValueInInterval(newLength, 0, len);
    for (; len > newLength; --len) array.removeLastObject();
  }

  @override
  ObjCObjectBase elementAt(int index) => array.objectAtIndex(index);

  @override
  Iterator<ObjCObjectBase> get iterator => _NSArrayIterator(this);

  @override
  ObjCObjectBase operator [](int index) => array.objectAtIndex(index);

  @override
  void operator []=(int index, ObjCObjectBase value) =>
      array.replaceObjectAtIndex(index, withObject: value);

  @override
  void add(ObjCObjectBase value) => array.addObject(value);
}

class _NSArrayIterator implements Iterator<ObjCObjectBase> {
  final Iterable<ObjCObjectBase> _iterable;
  final int _length;
  int _index;
  ObjCObjectBase? _current;

  _NSArrayIterator(Iterable<ObjCObjectBase> iterable)
    : _iterable = iterable,
      _length = iterable.length,
      _index = 0;

  @override
  ObjCObjectBase get current => _current!;

  @override
  @pragma('vm:prefer-inline')
  bool moveNext() {
    final length = _iterable.length;
    if (_length != length) {
      throw ConcurrentModificationError(_iterable);
    }
    if (_index >= length) {
      _current = null;
      return false;
    }
    _current = _iterable.elementAt(_index);
    _index++;
    return true;
  }
}