/// <summary>
/// Synchronizes the sort descriptions collection to the sort descriptors collection.
/// </summary>
/// <param name="descriptor">The descriptor that changed</param>
/// <param name="e">The property change event</param>
private void HandleSortDescriptorChanged(SortDescriptor descriptor, PropertyChangedEventArgs e)
{
this._ignoreChanges = true;
try
{
// We have to reset when the collections were not equal before the change
if (this._sourceCollection.Count != this._descriptionCollection.Count)
{
SortCollectionManager.ResetToSortDescriptors(this._descriptionCollection, this._sourceCollection);
}
else
{
int index = this._sourceCollection.IndexOf(descriptor);
SortDescription?description = SortCollectionManager.GetDescriptionFromDescriptor(descriptor);
if (!description.HasValue)
{
this._descriptionCollection.RemoveAt(index);
}
else
{
this._descriptionCollection[index] = description.Value;
}
}
}
finally
{
this._ignoreChanges = false;
}
}
/// <summary>
/// Resets the <paramref name="sortDescriptors"/> collection to match the <paramref name="sortDescriptions"/> collection.
/// </summary>
/// <param name="sortDescriptions">The collection to match</param>
/// <param name="sortDescriptors">The collection to reset</param>
private static void ResetToSortDescriptions(SortDescriptionCollection sortDescriptions, SortDescriptorCollection sortDescriptors)
{
sortDescriptors.Clear();
foreach (SortDescription description in sortDescriptions)
{
sortDescriptors.Add(SortCollectionManager.GetDescriptorFromDescription(description));
}
}
private void AssertCollectionsAreEquivalent()
{
if (this._sourceCollection.Count != this._descriptionCollection.Count)
{
// Collections may not be equivalent if a descriptor isn't fully defined
return;
}
Debug.Assert(SortCollectionManager.AreEquivalent(this._descriptionCollection, this._sourceCollection), "Collections should be equal.");
}
/// <summary>
/// Resets the <paramref name="sortDescriptions"/> collection to match the <paramref name="sortDescriptors"/> collection.
/// </summary>
/// <param name="sortDescriptions">The collection to reset</param>
/// <param name="sortDescriptors">The collection to match</param>
private static void ResetToSortDescriptors(SortDescriptionCollection sortDescriptions, SortDescriptorCollection sortDescriptors)
{
sortDescriptions.Clear();
foreach (SortDescriptor descriptor in sortDescriptors)
{
SortDescription?description = SortCollectionManager.GetDescriptionFromDescriptor(descriptor);
if (description.HasValue)
{
sortDescriptions.Add(description.Value);
}
}
}
/// <summary>
/// Synchronizes the sort descriptions collection to the sort descriptors collection.
/// </summary>
/// <param name="e">The collection change event</param>
private void HandleSortDescriptorCollectionChanged(NotifyCollectionChangedEventArgs e)
{
this._ignoreChanges = true;
try
{
// We have to reset in a number of situations
// 1) Resetting the SortDescriptors
// 2) Collections were not equal before replacing SortDescriptors
// 3) Collections were not equal before removing SortDescriptors
// 4) Collections were not equal before adding SortDescriptors
if ((e.Action == NotifyCollectionChangedAction.Reset) ||
((e.Action == NotifyCollectionChangedAction.Replace) && ((this._sourceCollection.Count + e.OldItems.Count) != (this._descriptionCollection.Count + e.NewItems.Count))) ||
((e.Action == NotifyCollectionChangedAction.Remove) && ((this._sourceCollection.Count + e.OldItems.Count) != this._descriptionCollection.Count)) ||
((e.Action == NotifyCollectionChangedAction.Add) && (this._sourceCollection.Count != (this._descriptionCollection.Count + e.NewItems.Count))))
{
SortCollectionManager.ResetToSortDescriptors(this._descriptionCollection, this._sourceCollection);
}
else
{
if ((e.Action == NotifyCollectionChangedAction.Remove) ||
(e.Action == NotifyCollectionChangedAction.Replace))
{
int index = e.OldStartingIndex;
if (e.Action == NotifyCollectionChangedAction.Replace) // TODO: This is a DependencyObjectCollection bug!
{
index = e.NewStartingIndex;
}
for (int i = 0; i < e.OldItems.Count; i++)
{
this._descriptionCollection.RemoveAt(index);
}
}
if ((e.Action == NotifyCollectionChangedAction.Add) ||
(e.Action == NotifyCollectionChangedAction.Replace))
{
int index = e.NewStartingIndex;
foreach (object item in e.NewItems)
{
SortDescription?description = SortCollectionManager.GetDescriptionFromDescriptor((SortDescriptor)item);
if (description.HasValue)
{
this._descriptionCollection.Insert(index++, description.Value);
}
}
}
}
}
finally
{
this._ignoreChanges = false;
}
}
/// <summary>
/// Determines whether the <paramref name="sortDescriptions"/> are equivalent to the <paramref name="sortDescriptors"/>.
/// </summary>
/// <param name="sortDescriptions">The descriptions to compare</param>
/// <param name="sortDescriptors">The descriptors to compare</param>
/// <returns><c>true</c> if the collections are equivalent</returns>
public static bool AreEquivalent(SortDescriptionCollection sortDescriptions, SortDescriptorCollection sortDescriptors)
{
Debug.Assert((sortDescriptions != null) && (sortDescriptors != null), "Both should be non-null.");
if (sortDescriptions.Count != sortDescriptors.Count)
{
return(false);
}
for (int i = 0, count = sortDescriptions.Count; i < count; i++)
{
if (!SortCollectionManager.AreEquivalent(sortDescriptions[i], sortDescriptors[i]))
{
return(false);
}
}
return(true);
}
