/// <summary>
/// Request to change the virtual results
/// </summary>
/// <param name="request">The request.</param>
/// <exception cref="System.ArgumentNullException">request</exception>
public void Virtualise(IVirtualRequest request)
{
if (request == null) throw new ArgumentNullException(nameof(request));
_request = request;
_subject.OnNext(_request);
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualisingController"/> class.
/// </summary>
/// <param name="request">The request.</param>
/// <exception cref="System.ArgumentNullException">request</exception>
public VirtualisingController(IVirtualRequest request)
{
if (request == null) throw new ArgumentNullException(nameof(request));
_request = request;
_subject.OnNext(_request);
}
/// <summary>
/// Request to change the virtual results
/// </summary>
/// <param name="request">The request.</param>
/// <exception cref="System.ArgumentNullException">request</exception>
public void Virtualise(IVirtualRequest request)
{
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
_request = request;
_subject.OnNext(_request);
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualisingController"/> class.
/// </summary>
/// <param name="request">The request.</param>
/// <exception cref="System.ArgumentNullException">request</exception>
public VirtualisingController(IVirtualRequest request)
{
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
_request = request;
_subject.OnNext(_request);
}
private IChangeSet <T> Virtualise(List <T> all, ChangeAwareList <T> virtualised, IVirtualRequest request)
{
if (request == null || request.StartIndex < 0 || request.Size < 1)
{
return(null);
}
_parameters = request;
return(Virtualise(all, virtualised));
}
private IChangeSet <T> Virtualise(IVirtualRequest request)
{
if (request == null || request.StartIndex < 0 || request.Size < 1)
{
return(null);
}
_parameters = request;
return(Virtualise());
}
public IVirtualChangeSet <TObject, TKey> Virtualise(IVirtualRequest parameters)
{
if (parameters == null || parameters.StartIndex < 0 || parameters.Size < 1)
{
return(null);
}
if (parameters.Size == _parameters.Size && parameters.StartIndex == _parameters.StartIndex)
{
return(null);
}
_parameters = parameters;
return(Virtualise());
}
public Virtualiser(VirtualRequest request = null)
{
_parameters = request ?? new VirtualRequest();
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualisingController"/> class.
/// </summary>
public VirtualisingController()
{
_request = new VirtualRequest(0, 30);
_subject.OnNext(_request);
}
private static IChangeSet <T> Virtualise(IList <T> all, ChangeAwareList <T> virtualised, IVirtualRequest request, IChangeSet <T>?changeSet = null)
{
if (changeSet is not null)
{
all.Clone(changeSet);
}
var previous = virtualised;
var current = all.Skip(request.StartIndex).Take(request.Size).ToList();
var adds = current.Except(previous);
var removes = previous.Except(current);
virtualised.RemoveMany(removes);
adds.ForEach(
t =>
{
var index = current.IndexOf(t);
virtualised.Insert(index, t);
});
var moves = changeSet.EmptyIfNull().Where(change => change.Reason == ListChangeReason.Moved && change.MovedWithinRange(request.StartIndex, request.StartIndex + request.Size));
foreach (var change in moves)
{
// check whether an item has moved within the same page
var currentIndex = change.Item.CurrentIndex - request.StartIndex;
var previousIndex = change.Item.PreviousIndex - request.StartIndex;
virtualised.Move(previousIndex, currentIndex);
}
// find replaces [Is this ever the case that it can be reached]
for (var i = 0; i < current.Count; i++)
{
var currentItem = current[i];
var previousItem = previous[i];
if (ReferenceEquals(currentItem, previousItem))
{
continue;
}
var index = virtualised.IndexOf(currentItem);
virtualised.Move(i, index);
}
return(virtualised.CaptureChanges());
}
private IChangeSet <T> CheckParamsAndVirtualise(List <T> all, ChangeAwareList <T> virtualised, IVirtualRequest request)
{
if (request == null || request.StartIndex < 0 || request.Size < 1)
{
return(null);
}
return(Virtualise(all, virtualised, request));
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualisingController"/> class.
/// </summary>
public VirtualisingController()
{
_request = new VirtualRequest(0, 30);
_subject.OnNext(_request);
}
