/// <summary>
/// Synchronize with an object controller.
/// </summary>
/// <typeparam name="T">Type of element in the collection.</typeparam>
/// <param name="controller">The controller to synchronize with.</param>
/// <param name="collectionChangedArgs">Description of what has changed.</param>
public static void SynchronizeCollection <T>(this NSObjectController controller, NotifyCollectionChangedEventArgs collectionChangedArgs) where T : class
{
switch (collectionChangedArgs.Action)
{
case NotifyCollectionChangedAction.Add:
for (int i = 0; i < collectionChangedArgs.NewItems.Count; i++)
{
var item = collectionChangedArgs.NewItems[i] as T;
var nsObject = item as NSObject;
if (nsObject != null)
{
controller.AddObject(nsObject);
DebugOutput("SynchronizeCollection: added " + collectionChangedArgs.NewItems[i] + " of type " + collectionChangedArgs.NewItems[i].GetType().FullName);
DebugOutput("SynchronizeCollection: item as NSObject is " + nsObject + ", is null? " + (nsObject == null));
}
}
break;
case NotifyCollectionChangedAction.Move:
ErrorReporting.ReportNotImplementedError("ObservableColletionHelpers.SynchronizeCollection:NotifyCollectionChangedAction.Move");
break;
case NotifyCollectionChangedAction.Remove:
for (int i = 0; i < collectionChangedArgs.OldItems.Count; i++)
{
var item = collectionChangedArgs.OldItems[i] as T;
var nsObject = item as NSObject;
if (nsObject != null)
{
controller.RemoveObject(nsObject);
DebugOutput("SynchronizeCollection: removed " + collectionChangedArgs.OldItems[i] + " of type " + collectionChangedArgs.OldItems[i].GetType().FullName);
}
}
break;
case NotifyCollectionChangedAction.Replace:
// remove
for (int i = 0; i < collectionChangedArgs.OldItems.Count; i++)
{
var item = collectionChangedArgs.OldItems[i] as T;
var nsObject = item as NSObject;
if (nsObject != null)
{
controller.RemoveObject(nsObject);
}
}
// add
for (int i = 0; i < collectionChangedArgs.NewItems.Count; i++)
{
var item = collectionChangedArgs.NewItems[i] as T;
var nsObject = item as NSObject;
if (item != null)
{
controller.AddObject(nsObject);
}
}
break;
case NotifyCollectionChangedAction.Reset:
ErrorReporting.ReportNotImplementedError("ObservableColletionHelpers.SynchronizeCollection:NotifyCollectionChangedAction.Reset");
break;
default:
break;
}
}
/// <summary>
/// Offers a simple one-way sync operation to add / remove items to / from a collection via the collection changed event data.
/// </summary>
/// <typeparam name="T">The type of elements in the collection.</typeparam>
/// <param name="targetCollection">The collection to be updated, based upon the collection changed arguments.</param>
/// <param name="collectionChangedArgs">Event arguments describing how a source collection has changed.</param>
/// <remarks>Does not support move operations.</remarks>
/// <exception cref="NotImplementedException">Thrown if the collection changed event arguments describe a move operation.</exception>
public static void SynchronizeCollection <T>(this ObservableCollection <T> targetCollection, NotifyCollectionChangedEventArgs collectionChangedArgs) where T : class
{
switch (collectionChangedArgs.Action)
{
case NotifyCollectionChangedAction.Add:
for (int i = 0; i < collectionChangedArgs.NewItems.Count; i++)
{
var item = collectionChangedArgs.NewItems[i] as T;
if (item != null)
{
targetCollection.Add(item);
}
}
break;
case NotifyCollectionChangedAction.Move:
ErrorReporting.ReportNotImplementedError("ObservableColletionHelpers.SynchronizeCollection:NotifyCollectionChangedAction.Move");
break;
case NotifyCollectionChangedAction.Remove:
for (int i = 0; i < collectionChangedArgs.OldItems.Count; i++)
{
var item = collectionChangedArgs.OldItems[i] as T;
if (item != null)
{
targetCollection.Remove(item);
}
}
break;
case NotifyCollectionChangedAction.Replace:
// remove
for (int i = 0; i < collectionChangedArgs.OldItems.Count; i++)
{
var item = collectionChangedArgs.OldItems[i] as T;
if (item != null)
{
targetCollection.Remove(item);
}
}
// add
for (int i = 0; i < collectionChangedArgs.NewItems.Count; i++)
{
var item = collectionChangedArgs.NewItems[i] as T;
if (item != null)
{
targetCollection.Add(item);
}
}
break;
case NotifyCollectionChangedAction.Reset:
targetCollection.Clear();
if (collectionChangedArgs.NewItems != null)
{
for (int i = 0; i < collectionChangedArgs.NewItems.Count; i++)
{
var item = collectionChangedArgs.NewItems[i] as T;
if (item != null)
{
targetCollection.Add(item);
}
}
}
break;
default:
break;
}
}
