/// <summary>
/// Synchronizes the group descriptions collection to the group descriptors collection.
/// </summary>
/// <param name="descriptor">The descriptor that changed</param>
/// <param name="e">The property change event</param>
private void HandleGroupDescriptorChanged(GroupDescriptor 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)
{
GroupCollectionManager.ResetToGroupDescriptors(this._descriptionCollection, this._sourceCollection);
}
else
{
int index = this._sourceCollection.IndexOf(descriptor);
GroupDescription description = GroupCollectionManager.GetDescriptionFromDescriptor(descriptor);
if (description == null)
{
this._descriptionCollection.RemoveAt(index);
}
else
{
this._descriptionCollection[index] = description;
}
}
}
finally
{
this._ignoreChanges = false;
}
}
/// <summary>
/// Resets the <paramref name="groupDescriptors"/> collection to match the <paramref name="groupDescriptions"/> collection.
/// </summary>
/// <param name="groupDescriptions">The collection to match</param>
/// <param name="groupDescriptors">The collection to reset</param>
private static void ResetToGroupDescriptions(ObservableCollection <GroupDescription> groupDescriptions, GroupDescriptorCollection groupDescriptors)
{
groupDescriptors.Clear();
foreach (GroupDescription description in groupDescriptions)
{
groupDescriptors.Add(GroupCollectionManager.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(GroupCollectionManager.AreEquivalent(this._descriptionCollection, this._sourceCollection), "Collections should be equal.");
}
/// <summary>
/// Resets the <paramref name="groupDescriptions"/> collection to match the <paramref name="groupDescriptors"/> collection.
/// </summary>
/// <param name="groupDescriptions">The collection to reset</param>
/// <param name="groupDescriptors">The collection to match</param>
private static void ResetToGroupDescriptors(ObservableCollection <GroupDescription> groupDescriptions, GroupDescriptorCollection groupDescriptors)
{
groupDescriptions.Clear();
foreach (GroupDescriptor descriptor in groupDescriptors)
{
GroupDescription description = GroupCollectionManager.GetDescriptionFromDescriptor(descriptor);
if (description != null)
{
groupDescriptions.Add(description);
}
}
}
/// <summary>
/// Synchronizes the group descriptions collection to the group descriptors collection.
/// </summary>
/// <param name="e">The collection change event</param>
private void HandleGroupDescriptorCollectionChanged(NotifyCollectionChangedEventArgs e)
{
this._ignoreChanges = true;
try
{
// We have to reset in a number of situations
// 1) Resetting the GroupDescriptors
// 2) Collections were not equal before replacing GroupDescriptors
// 3) Collections were not equal before removing GroupDescriptors
// 4) Collections were not equal before adding GroupDescriptors
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))))
{
GroupCollectionManager.ResetToGroupDescriptors(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)
{
GroupDescription description = GroupCollectionManager.GetDescriptionFromDescriptor((GroupDescriptor)item);
if (description != null)
{
this._descriptionCollection.Insert(index++, description);
}
}
}
}
}
finally
{
this._ignoreChanges = false;
}
}
/// <summary>
/// Determines whether the <paramref name="groupDescriptions"/> are equivalent to the <paramref name="groupDescriptors"/>.
/// </summary>
/// <param name="groupDescriptions">The descriptions to compare</param>
/// <param name="groupDescriptors">The descriptors to compare</param>
/// <returns><c>true</c> if the collections are equivalent</returns>
private static bool AreEquivalent(ObservableCollection <GroupDescription> groupDescriptions, GroupDescriptorCollection groupDescriptors)
{
Debug.Assert((groupDescriptions != null) && (groupDescriptors != null), "Both should be non-null.");
if (groupDescriptions.Count != groupDescriptors.Count)
{
return(false);
}
for (int i = 0, count = groupDescriptions.Count; i < count; i++)
{
if (!GroupCollectionManager.AreEquivalent(groupDescriptions[i], groupDescriptors[i]))
{
return(false);
}
}
return(true);
}
