FModel/FModel/Framework/RangeObservableCollection.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;

namespace FModel.Framework;

public sealed class RangeObservableCollection<T> : ObservableCollection<T>
{
    private static readonly PropertyChangedEventArgs CountChanged = new(nameof(Count));
    private static readonly PropertyChangedEventArgs IndexerChanged = new("Item[]");
    private bool _suppressNotification;

    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        if (!_suppressNotification)
            base.OnCollectionChanged(e);
    }

    public void AddRange(IEnumerable<T> list)
    {
        if (list == null)
            throw new ArgumentNullException(nameof(list));

        var changed = false;
        foreach (var item in list)
        {
            Items.Add(item);
            changed = true;
        }

        if (!changed || _suppressNotification)
            return;

        OnPropertyChanged(CountChanged);
        OnPropertyChanged(IndexerChanged);
        OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
    }

    /// <summary>
    /// Adds an item while constructing a collection that has not been published to a binding yet.
    /// </summary>
    public void AddWithoutNotification(T item) => Items.Add(item);

    public void SetSuppressionState(bool state)
    {
        _suppressNotification = state;
    }

    public void InvokeOnCollectionChanged(NotifyCollectionChangedAction changedAction = NotifyCollectionChangedAction.Reset)
    {
        OnCollectionChanged(new NotifyCollectionChangedEventArgs(changedAction));
    }
}