EmptyCollectionToObjectConverter.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Collections;

namespace CommunityToolkit.WinUI.Converters;

/// <summary>
/// This class converts a collection size into an other object.
/// Can be used to convert to bind a visibility, a color or an image to the size of the collection.
/// </summary>
public partial class EmptyCollectionToObjectConverter : EmptyObjectToObjectConverter
{
    /// <summary>
    /// Checks collection for emptiness.
    /// </summary>
    /// <param name="value">Value to be checked.</param>
    /// <returns>True if value is an empty collection or does not implement IEnumerable, false otherwise.</returns>
    protected override bool CheckValueIsEmpty(object value)
    {
        bool isEmpty = true;
        var collection = value as IEnumerable;
        if (collection != null)
        {
            var enumerator = collection.GetEnumerator();
            isEmpty = !enumerator.MoveNext();
        }

        return isEmpty;
    }
}