/// <summary>
/// Construtor for ChangeReason.Move
/// </summary>
/// <param name="current">The current.</param>
/// <param name="currentIndex">The CurrentIndex.</param>
/// <param name="previousIndex">CurrentIndex of the previous.</param>
/// <exception cref="System.ArgumentException">
/// CurrentIndex must be greater than or equal to zero
/// or
/// PreviousIndex must be greater than or equal to zero
/// </exception>
public Change(T current, int currentIndex, int previousIndex)
{
if (currentIndex < 0)
{
throw new ArgumentException("CurrentIndex must be greater than or equal to zero");
}
if (previousIndex < 0)
{
throw new ArgumentException("PreviousIndex must be greater than or equal to zero");
}
Reason = ListChangeReason.Moved;
Item = new ItemChange <T>(Reason, current, Optional.None <T>(), currentIndex, previousIndex);
}
/// <summary>
/// Initializes a new instance of the <see cref="Change{TObject,TKey}" /> struct.
/// </summary>
/// <param name="reason">The reason.</param>
/// <param name="current">The current.</param>
/// <param name="previous">The previous.</param>
/// <param name="currentIndex">Value of the current.</param>
/// <param name="previousIndex">Value of the previous.</param>
/// <exception cref="ArgumentException">
/// For ChangeReason.Add, a previous value cannot be specified
/// or
/// For ChangeReason.Change, must supply previous value
/// </exception>
/// <exception cref="System.ArgumentException">For ChangeReason.Add, a previous value cannot be specified
/// or
/// For ChangeReason.Change, must supply previous value</exception>
public Change(ListChangeReason reason, T current, Optional <T> previous, int currentIndex = -1, int previousIndex = -1)
{
if (reason == ListChangeReason.Add && previous.HasValue)
{
throw new ArgumentException("For ChangeReason.Add, a previous value cannot be specified");
}
if (reason == ListChangeReason.Replace && !previous.HasValue)
{
throw new ArgumentException("For ChangeReason.Change, must supply previous value");
}
if (reason == ListChangeReason.Refresh && currentIndex < 0)
{
throw new ArgumentException("For ChangeReason.Refresh, must supply and index");
}
Reason = reason;
Item = new ItemChange <T>(Reason, current, previous, currentIndex, previousIndex);
}
/// <summary>
/// Determines whether the specified object, is equal to this instance.
/// </summary>
/// <param name="other">The other.</param>
/// <returns></returns>
public bool Equals(ItemChange <T> other)
{
return(EqualityComparer <T> .Default.Equals(Current, other.Current) && CurrentIndex == other.CurrentIndex && Previous.Equals(other.Previous) && PreviousIndex == other.PreviousIndex);
}