Transaction-aware collection support for PhoneWave

PhoneWaveCollection.cs

public class PhoneWaveCollectionChangeAggregator<T> : TransactionChange
{
    List<(bool isRemove, int index, T item)> _changes = new();
     
    ObservableCollection<T> _target;

    public PhoneWaveCollectionChangeAggregator(ObservableCollection<T> target)
    { 
        _target = target;
    }

    public void AddItem(T item, int index) => _changes.Add((false, index, item));
    public void RemoveItem(T item, int index) => _changes.Add((true, index, item));

    public override void Rollback()
    {
        foreach(var change in Enumerable.Reverse(_changes))
        {
            if (change.isRemove) _target.Insert(change.index, change.item);
            else _target.RemoveAt(change.index);
        }
    }
    public override void RollForward()
    {
        foreach (var change in _changes)
        {
            if (!change.isRemove) _target.Insert(change.index, change.item);
            else _target.RemoveAt(change.index);
        }
    }
}

public class PhoneWaveCollection<T> : ObservableCollection<T>
{
    public PhoneWaveContext Context { get; }
    public PhoneWaveCollection(PhoneWaveContext context)
    {
        Context = context;
    }

    protected override void ClearItems()
    {
        for (int i = Count - 1; i >= 0; i--)
        {
            Context.UpdateCollection(this, true, i, this[i]);
        }
        base.ClearItems(); 
    }
    protected override void InsertItem(int index, T item)
    {
        Context.UpdateCollection(this, false, index, item);
        base.InsertItem(index, item);
    }
    protected override void MoveItem(int oldIndex, int newIndex)
    {
        var item = this[oldIndex];
        Context.UpdateCollection(this, true, oldIndex, item);
        Context.UpdateCollection(this, false, newIndex, item);

        base.MoveItem(oldIndex, newIndex);
    }
    protected override void RemoveItem(int index)
    {
        Context.UpdateCollection(this, true, index, this[index]); 
        base.RemoveItem(index);
    }
    protected override void SetItem(int index, T item)
    {
        Context.UpdateCollection(this, true, index, this[index]);
        Context.UpdateCollection(this, false, index, item);
        base.SetItem(index, item);
    }
}