/// <summary>
///
/// </summary>
/// <param name="context"></param>
/// <param name="keepAlive"></param>
/// <returns></returns>
public ITextUndoHistory RegisterHistory(object context, bool keepAlive)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (_strongContextMapping.TryGetValue(context, out var result))
{
if (!keepAlive)
{
_strongContextMapping.Remove(context);
_weakContextMapping.Add(new KeyWeakReference(context), result);
}
return(result);
}
var reference = new KeyWeakReference(context);
if (_weakContextMapping.TryGetValue(reference, out result))
{
if (keepAlive)
{
_weakContextMapping.Remove(reference);
_strongContextMapping.Add(context, result);
}
return(result);
}
result = new MockTextUndoHistory(this);
_histories.Add(result, 1);
if (keepAlive)
{
_strongContextMapping.Add(context, result);
}
else
{
_weakContextMapping.Add(reference, result);
}
return(result);
}
public bool Equals(KeyWeakReference other)
{
if (other == null)
{
return(false);
}
if (ReferenceEquals(this, other))
{
return(true);
}
if (IsAlive && other.IsAlive)
{
return(Equals(Target, other.Target));
}
return(!IsAlive && !other.IsAlive && HashCode == other.HashCode);
}