Pylon.ObservableList

ObservableList<T> is a simple, extensible list that emits INotifyCollectionChanged events for each mutable operation. If you find ObservableCollection<T> or AvaloniaList<T> incomplete for your use case, consider using and extending ObservableList<T> with your own custom operations.

Getting Started

Install the Pylon.ObservableList package.

dotnet add package Pylon.ObservableList

Compatibility

ObservableList<T> is intended to be used with Avalonia and is compatible with the mutable operations of AvaloniaList<T>. However, it should be usable with any INotifyCollectionChanged consumers. Listed below is the comparison between the mutable operations of each list.

ObservableList<T>	AvaloniaList<T>
Add(T)	Add(T)
AddRange(IEnumerable<T>)	AddRange(IEnumerable<T>)
Clear()	Clear()
Insert(int, T)	Insert(int, T)
InsertRange(int, IEnumerable<T>)	InsertRange(int, IEnumerable<T>)
Move(int int)	Move(int int)
MoveRange(int, int, int)	MoveRange(int, int, int)
Remove(T)	Remove(T)
RemoveAll(IEnumerable<T>)	RemoveAll(IEnumerable<T>)
RemoveAt(int)	RemoveAt(int)
RemoveRange(int, int)	RemoveRange(int, int)
this[int]	this[int]
Reverse()
Reverse(int, int)
RotateLeft(int)
RotateLeft(int, int, int)
RotateRight(int)
RotateRight(int, int, int)

Extending ObservableList<T>

ObservableList<T> exposes both the underlying Items list and methods for publishing INotifyCollectionChanged events. The example below demonstrates how to extend ObservableList<T> with custom operations.

public static class ObservableListExtensions
{
    public static void AddRange<T>(this ObservableList<T> list, IEnumerable<T> collection)
    {
        var index = list.Items.Count;
        list.Items.AddRange(collection);

        if (list.Items.Count > index)
        {
            if (list.CanNotify)
            {
                var @event = new NotifyCollectionChangedEventArgs(
                    NotifyCollectionChangedAction.Add,
                    list.Items[index..],
                    index);

                list.NotifyCollectionChanged(@event);
            }

            list.NotifyCountChanged();
        }
    }
}

More examples can be found in ObservableListExtensions.

Building

Build using dotnet.

dotnet build --configuration release

Test using dotnet.

dotnet test