private IVirtualChangeSet <TObject, TKey> Virtualise(ISortedChangeSet <TObject, TKey> updates = null)
{
if (_isLoaded == false)
{
return(null);
}
var previous = _current;
var virualised = _all.Skip(_parameters.StartIndex)
.Take(_parameters.Size)
.ToList();
_current = new KeyValueCollection <TObject, TKey>(virualised, _all.Comparer, updates?.SortedItems.SortReason ?? SortReason.DataChanged, _all.Optimisations);
////check for changes within the current virtualised page. Notify if there have been changes or if the overall count has changed
var notifications = _changedCalculator.Calculate(_current, previous, updates);
if (notifications.Count == 0 && (previous.Count != _current.Count))
{
return(null);
}
var response = new VirtualResponse(_parameters.Size, _parameters.StartIndex, _all.Count);
return(new VirtualChangeSet <TObject, TKey>(notifications, _current, response));
}
private void DoUpdate(ISortedChangeSet <TObject, TKey> updates, IObservableCollection <TObject> list)
{
updates.ForEach(update =>
{
switch (update.Reason)
{
case ChangeReason.Add:
list.Insert(update.CurrentIndex, update.Current);
break;
case ChangeReason.Remove:
list.RemoveAt(update.CurrentIndex);
break;
case ChangeReason.Moved:
list.Move(update.PreviousIndex, update.CurrentIndex);
break;
case ChangeReason.Update:
{
list.RemoveAt(update.PreviousIndex);
list.Insert(update.CurrentIndex, update.Current);
}
break;
}
});
}
/// <summary>
/// Maintains the specified collection from the changes
/// </summary>
/// <param name="changes">The changes.</param>
/// <param name="collection">The collection.</param>
public void Adapt(ISortedChangeSet <TObject, TKey> changes, IObservableCollection <TObject> collection)
{
switch (changes.SortedItems.SortReason)
{
case SortReason.InitialLoad:
{
if (changes.Count > _refreshThreshold())
{
using (collection.SuspendNotifications())
{
collection.Load(changes.SortedItems.Select(kv => kv.Value));
}
}
else
{
using (collection.SuspendCount())
{
DoUpdate(changes, collection);
}
}
}
break;
case SortReason.ComparerChanged:
case SortReason.Reset:
using (collection.SuspendNotifications())
{
collection.Load(changes.SortedItems.Select(kv => kv.Value));
}
break;
case SortReason.DataChanged:
if (changes.Count > _refreshThreshold())
{
using (collection.SuspendNotifications())
{
collection.Load(changes.SortedItems.Select(kv => kv.Value));
}
}
else
{
using (collection.SuspendCount())
{
DoUpdate(changes, collection);
}
}
break;
case SortReason.Reorder:
//Updates will only be moves, so appply logic
using (collection.SuspendCount())
{
DoUpdate(changes, collection);
}
break;
default:
throw new ArgumentOutOfRangeException();
}
}
private void DoUpdate(ISortedChangeSet <TObject, TKey> changes)
{
foreach (var change in changes)
{
switch (change.Reason)
{
case ChangeReason.Add:
_list.Insert(change.CurrentIndex, change.Current);
break;
case ChangeReason.Remove:
_list.RemoveAt(change.CurrentIndex);
break;
case ChangeReason.Moved:
_list.RemoveAt(change.PreviousIndex);
_list.Insert(change.CurrentIndex, change.Current);
break;
case ChangeReason.Update:
_list.RemoveAt(change.PreviousIndex);
_list.Insert(change.CurrentIndex, change.Current);
break;
}
}
}
private IPagedChangeSet <TObject, TKey>?Paginate(ISortedChangeSet <TObject, TKey>?updates = null)
{
if (_isLoaded == false)
{
return(null);
}
var previous = _current;
int pages = CalculatePages();
int page = _request.Page > pages ? pages : _request.Page;
int skip = _request.Size * (page - 1);
var paged = _all.Skip(skip).Take(_request.Size).ToList();
_current = new KeyValueCollection <TObject, TKey>(paged, _all.Comparer, updates?.SortedItems.SortReason ?? SortReason.DataChanged, _all.Optimisations);
// check for changes within the current virtualised page. Notify if there have been changes or if the overall count has changed
var notifications = FilteredIndexCalculator <TObject, TKey> .Calculate(_current, previous, updates);
if (notifications.Count == 0 && (previous.Count != _current.Count))
{
return(null);
}
var response = new PageResponse(_request.Size, _all.Count, page, pages);
return(new PagedChangeSet <TObject, TKey>(_current, notifications, response));
}
private void DoUpdate(ISortedChangeSet <TObject, TKey> updates, IObservableCollection <TObject> list)
{
foreach (var update in updates)
{
switch (update.Reason)
{
case ChangeReason.Add:
list.Insert(update.CurrentIndex, update.Current);
break;
case ChangeReason.Remove:
list.RemoveAt(update.CurrentIndex);
break;
case ChangeReason.Moved:
list.Move(update.PreviousIndex, update.CurrentIndex);
break;
case ChangeReason.Update:
if (update.PreviousIndex != update.CurrentIndex)
{
list.RemoveAt(update.PreviousIndex);
list.Insert(update.CurrentIndex, update.Current);
}
else
{
list.Replace(update.Previous.Value, update.Current);
}
break;
}
}
}
/// <inheritdoc />
public void Adapt(ISortedChangeSet <TObject, TKey> changes)
{
if (changes == null)
{
throw new ArgumentNullException(nameof(changes));
}
switch (changes.SortedItems.SortReason)
{
case SortReason.InitialLoad:
case SortReason.ComparerChanged:
case SortReason.Reset:
using (new BindingListEventsSuspender <TObject>(_list))
{
_list.Clear();
_list.AddRange(changes.SortedItems.Select(kv => kv.Value));
}
break;
case SortReason.DataChanged:
if (changes.Count - changes.Refreshes > _refreshThreshold)
{
using (new BindingListEventsSuspender <TObject>(_list))
{
_list.Clear();
_list.AddRange(changes.SortedItems.Select(kv => kv.Value));
}
}
else
{
DoUpdate(changes);
}
break;
case SortReason.Reorder:
DoUpdate(changes);
break;
default:
throw new ArgumentOutOfRangeException(nameof(changes));
}
}
/// <summary>
/// Adapts the specified sorted changeset
/// </summary>
/// <param name="changes">The changes.</param>
public void Adapt(ISortedChangeSet <TObject, TKey> changes)
{
switch (changes.SortedItems.SortReason)
{
case SortReason.InitialLoad:
case SortReason.ComparerChanged:
case SortReason.Reset:
{
using (_target.SuppressChangeNotifications())
{
_target.Clear();
_target.AddRange(changes.SortedItems.Select(kv => kv.Value));
}
}
break;
case SortReason.DataChanged:
{
if (changes.Count > _resetThreshold)
{
using (_target.SuppressChangeNotifications())
{
_target.Clear();
_target.AddRange(changes.SortedItems.Select(kv => kv.Value));
}
}
else
{
DoUpdate(changes);
}
}
break;
case SortReason.Reorder:
//Updates will only be moves, so appply logic
DoUpdate(changes);
break;
default:
throw new ArgumentOutOfRangeException();
}
}
public void TreatMovesAsRemoveAdd()
{
var cache = new SourceCache <Person, string>(p => p.Name);
var people = Enumerable.Range(0, 10).Select(age => new Person("Person" + age, age)).ToList();
var importantGuy = people.First();
cache.AddOrUpdate(people);
ISortedChangeSet <Person, string> latestSetWithoutMoves = null;
ISortedChangeSet <Person, string> latestSetWithMoves = null;
var boundList1 = new ReactiveList <Person>();
var boundList2 = new ReactiveList <Person>();
using (cache.Connect()
.AutoRefresh(p => p.Age)
.Sort(SortExpressionComparer <Person> .Ascending(p => p.Age))
.TreatMovesAsRemoveAdd()
.Bind(boundList1)
.Subscribe(set => latestSetWithoutMoves = set))
using (cache.Connect()
.AutoRefresh(p => p.Age)
.Sort(SortExpressionComparer <Person> .Ascending(p => p.Age))
.Bind(boundList2)
.Subscribe(set => latestSetWithMoves = set))
{
importantGuy.Age = importantGuy.Age + 200;
latestSetWithoutMoves.Removes.Should().Be(1);
latestSetWithoutMoves.Adds.Should().Be(1);
latestSetWithoutMoves.Moves.Should().Be(0);
latestSetWithoutMoves.Updates.Should().Be(0);
latestSetWithMoves.Moves.Should().Be(1);
latestSetWithMoves.Updates.Should().Be(0);
latestSetWithMoves.Removes.Should().Be(0);
latestSetWithMoves.Adds.Should().Be(0);
}
}
public void TreatMovesAsRemoveAdd()
{
var cache = new SourceCache <Person, string>(p => p.Name);
var people = Enumerable.Range(0, 10).Select(age => new Person("Person" + age, age)).ToList();
var importantGuy = people.First();
cache.AddOrUpdate(people);
ISortedChangeSet <Person, string>?latestSetWithoutMoves = null;
ISortedChangeSet <Person, string>?latestSetWithMoves = null;
var boundList1 = new ObservableCollectionExtended <Person>();
var boundList2 = new ObservableCollectionExtended <Person>();
using (cache.Connect().AutoRefresh(p => p.Age).Sort(SortExpressionComparer <Person> .Ascending(p => p.Age)).TreatMovesAsRemoveAdd().Bind(boundList1).Subscribe(set => latestSetWithoutMoves = set))
using (cache.Connect().AutoRefresh(p => p.Age).Sort(SortExpressionComparer <Person> .Ascending(p => p.Age)).Bind(boundList2).Subscribe(set => latestSetWithMoves = set))
{
if (latestSetWithoutMoves is null)
{
throw new InvalidOperationException(nameof(latestSetWithoutMoves));
}
if (latestSetWithMoves is null)
{
throw new InvalidOperationException(nameof(latestSetWithMoves));
}
importantGuy.Age += 200;
latestSetWithoutMoves.Should().NotBeNull();
latestSetWithoutMoves.Removes.Should().Be(1);
latestSetWithoutMoves.Adds.Should().Be(1);
latestSetWithoutMoves.Moves.Should().Be(0);
latestSetWithoutMoves.Updates.Should().Be(0);
latestSetWithMoves.Moves.Should().Be(1);
latestSetWithMoves.Updates.Should().Be(0);
latestSetWithMoves.Removes.Should().Be(0);
latestSetWithMoves.Adds.Should().Be(0);
}
}
public IVirtualChangeSet <TObject, TKey> Update(ISortedChangeSet <TObject, TKey> updates)
{
_isLoaded = true;
_all = updates.SortedItems;
return(Virtualise(updates));
}
public IPagedChangeSet <TObject, TKey>?Update(ISortedChangeSet <TObject, TKey> updates)
{
_isLoaded = true;
_all = updates.SortedItems;
return(Paginate(updates));
}