private NotifyRangedCollectionChangedEventArgs CreateEventArgs(NotifyCollectionChangedAction action, IList newItems = null, IList removedItems = null, IList <int> changedIndices = null)
{
NotifyRangedCollectionChangedEventArgs eventArgs;
if (newItems == null && removedItems == null && changedIndices == null)
{
eventArgs = new NotifyRangedCollectionChangedEventArgs(action);
}
else
{
eventArgs = new NotifyRangedCollectionChangedEventArgs(action, newItems, removedItems, changedIndices);
}
return(eventArgs);
}
/// <summary>
/// Consolidate changed items and indexes from <paramref name="other" /> into <paramref name="instance" /> by append.
/// </summary>
/// <param name="instance">The instance</param>
/// <param name="other">The other instance.</param>
public static bool ConsolidateItemsByAppend(this NotifyRangedCollectionChangedEventArgs instance, NotifyRangedCollectionChangedEventArgs other)
{
if (other.Indices.Count == 0)
{
return(false);
}
instance.Indices.AddRange(other.Indices);
foreach (var item in other.ChangedItems)
{
instance.ChangedItems.Add(item);
}
other.Indices.Clear();
other.ChangedItems.Clear();
return(true);
}
private NotifyRangedCollectionChangedEventArgs CreateEventArgs(NotifyCollectionChangedAction action, T changedItem = default(T), int changedIndex = -1)
{
NotifyRangedCollectionChangedEventArgs eventArgs;
if (changedItem == null)
{
eventArgs = new NotifyRangedCollectionChangedEventArgs(action);
}
else
{
eventArgs = new NotifyRangedCollectionChangedEventArgs(action, new List <T>()
{
changedItem
}, new List <int>()
{
changedIndex
});
}
return(eventArgs);
}
/// <summary>
/// Consolidates changed items and indexes from <paramref name="other" /> into <paramref name="instance" />.
/// </summary>
/// <param name="instance">The instance</param>
/// <param name="other">The other instance.</param>
/// <returns><c>True</c> if consolidation was executed; otherwise <c>False</c></returns>
public static bool ConsolidateItems(this NotifyRangedCollectionChangedEventArgs instance, NotifyRangedCollectionChangedEventArgs other)
{
if (instance.Indices.Count == 0 || other.Indices.Count == 0)
{
return(false);
}
if (instance.Indices.Count > other.Indices.Count)
{
var backup = instance;
instance = other;
other = backup;
}
var consolidated = false;
for (var i = instance.Indices.Count - 1; i >= 0; i--)
{
var idx = other.Indices.IndexOf(instance.Indices[i]);
while (idx != -1 && !Equals(other.ChangedItems[idx], instance.ChangedItems[i]))
{
idx = other.Indices.IndexOf(instance.Indices[i], idx + 1);
}
if (idx != -1)
{
other.Indices.RemoveAt(idx);
other.ChangedItems.RemoveAt(idx);
instance.Indices.RemoveAt(i);
instance.ChangedItems.RemoveAt(i);
consolidated = true;
}
}
return(consolidated);
}
