/// <summary>
/// Provides a secure method for setting the Behaviors property.
/// This dependency property indicates ....
/// </summary>
private static void SetBehaviors(DependencyObject d, BehaviorBindingCollection value)
{
d.SetValue(BehaviorsPropertyKey, value);
INotifyCollectionChanged collection = (INotifyCollectionChanged)value;
collection.CollectionChanged += new NotifyCollectionChangedEventHandler(CollectionChanged);
}
private static void TryRemoveStyleBehaviors(BehaviorBindingCollection behaviors, IList behaviorsToRemove, bool disposeBehaviors)
{
if (disposeBehaviors)
{
foreach (BehaviorBinding behavior in behaviorsToRemove.OfType <BehaviorBinding>())
{
behavior.Behavior.Dispose();
}
}
if (behaviors != null)
{
for (int i = 0; i < behaviorsToRemove.Count; i++)
{
for (int j = 0; j < behaviors.Count; j++)
{
if (((Behavior)behaviorsToRemove[i]).Id == behaviors[j].Id)
{
// We don't need to dispose the behaviors from the 'behaviors' colelction parameter here, because they will be disposed automatically by the CollectionChanged event handler
behaviors.RemoveAt(j);
}
}
}
}
}
/// <summary>
/// Provides a secure method for setting the Behaviors property.
/// This dependency property indicates ....
/// </summary>
public static void SetBehaviors(DependencyObject d, BehaviorBindingCollection value)
{
d.SetValue(BehaviorsPropertyKey, value);
INotifyCollectionChanged collection = value;
collection.CollectionChanged += CollectionChanged;
}
private static void AddStyleBehaviors(BehaviorBindingCollection behaviors, IList behaviorsToAdd)
{
foreach (Behavior behavior in behaviorsToAdd)
{
Behavior _behavior = behavior.Clone() as Behavior;
behaviors.Add(_behavior as Behavior);
behavior.Id = _behavior.Id;
}
}
/// <summary>
/// Gets the Behaviors property.
/// Here we initialze the collection and set the Owner property
/// </summary>
public static BehaviorBindingCollection GetBehaviors(DependencyObject d)
{
if (d == null)
{
throw new InvalidOperationException("The dependency object trying to attach to is set to null");
}
BehaviorBindingCollection collection = d.GetValue(CommandBehaviorCollection.BehaviorsProperty) as BehaviorBindingCollection;
if (collection == null)
{
collection = new BehaviorBindingCollection();
collection.Owner = d;
SetBehaviors(d, collection);
}
return(collection);
}
/// <summary>
/// Gets the Behaviors property.
/// Here we initialze the collection and set the Owner property
/// </summary>
public static BehaviorBindingCollection GetBehaviors(DependencyObject d)
{
if (d == null)
{
throw new InvalidOperationException("The dependency object trying to attach to is set to null");
}
if (!(d.GetValue(BehaviorsProperty) is BehaviorBindingCollection collection))
{
collection = new BehaviorBindingCollection
{
Owner = d
};
SetBehaviors(d, collection);
}
return(collection);
}
static void StyleCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
BehaviorBindingCollection sourceCollection = (BehaviorBindingCollection)sender;
switch (e.Action)
{
//when an item(s) is added we need to set the Owner property implicitly
case NotifyCollectionChangedAction.Add:
if (e.NewItems != null)
{
AddStyleBehaviors(GetBehaviors(sourceCollection.Owner), e.NewItems);
}
break;
//when an item(s) is removed we should Dispose the BehaviorBinding
case NotifyCollectionChangedAction.Remove:
case NotifyCollectionChangedAction.Reset:
if (e.OldItems != null)
{
TryRemoveStyleBehaviors(GetBehaviors(sourceCollection.Owner), e.OldItems, false);
}
break;
//here we have to set the owner property to the new item and unregister the old item
case NotifyCollectionChangedAction.Replace:
TryReplaceStyleBehaviors(GetBehaviors(sourceCollection.Owner), e.OldItems, e.NewItems, false);
break;
case NotifyCollectionChangedAction.Move:
throw new InvalidOperationException("Move is not supported for style behaviors");
default:
break;
}
}
private static void TryReplaceStyleBehaviors(BehaviorBindingCollection behaviors, IList oldBehaviors, IList newBehaviors, bool disposeBehaviors)
{
for (int i = 0; i < oldBehaviors.Count; i++)
{
Behavior oldItem = (Behavior)oldBehaviors[i];
Behavior newItem = (Behavior)newBehaviors[i];
Behavior clonedBehavior = newItem.Clone() as Behavior;
newItem.Owner = clonedBehavior.Owner = behaviors.Owner;
newItem.Id = oldItem.Id;
if (disposeBehaviors)
{
(oldItem as BehaviorBinding)?.Behavior.Dispose();
}
for (int j = 0; j < behaviors.Count; j++)
{
if (behaviors[j].Id == oldItem.Id)
{
behaviors[j] = clonedBehavior;
}
}
}
}
static void CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
BehaviorBindingCollection sourceCollection = (BehaviorBindingCollection)sender;
switch (e.Action)
{
//when an item(s) is added we need to set the Owner property implicitly
case NotifyCollectionChangedAction.Add:
if (e.NewItems != null)
{
foreach (BehaviorBinding item in e.NewItems)
{
item.Owner = sourceCollection.Owner;
}
}
break;
//when an item(s) is removed we should Dispose the BehaviorBinding
case NotifyCollectionChangedAction.Remove:
if (e.OldItems != null)
{
foreach (BehaviorBinding item in e.OldItems)
{
item.Behavior.Dispose();
}
}
break;
//here we have to set the owner property to the new item and unregister the old item
case NotifyCollectionChangedAction.Replace:
if (e.NewItems != null)
{
foreach (BehaviorBinding item in e.NewItems)
{
item.Owner = sourceCollection.Owner;
}
}
if (e.OldItems != null)
{
foreach (BehaviorBinding item in e.OldItems)
{
item.Behavior.Dispose();
}
}
break;
//when an item(s) is removed we should Dispose the BehaviorBinding
case NotifyCollectionChangedAction.Reset:
if (e.OldItems != null)
{
foreach (BehaviorBinding item in e.OldItems)
{
item.Behavior.Dispose();
}
}
break;
case NotifyCollectionChangedAction.Move:
default:
break;
}
}
static void CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
BehaviorBindingCollection sourceCollection = (BehaviorBindingCollection)sender;
switch (e.Action)
{
//when an item(s) is added we need to set the Owner property implicitly
case NotifyCollectionChangedAction.Add:
if (e.NewItems != null)
{
foreach (Behavior item in e.NewItems)
{
item.Owner = sourceCollection.Owner;
item.Id = GetId(sourceCollection);
}
}
break;
//when an item(s) is removed we should Dispose the BehaviorBinding
case NotifyCollectionChangedAction.Remove:
case NotifyCollectionChangedAction.Reset:
if (e.OldItems != null)
{
TryRemoveStyleBehaviors(GetStyleBehaviors(sourceCollection.Owner), e.OldItems, true);
}
break;
//here we have to set the owner property to the new item and unregister the old item
case NotifyCollectionChangedAction.Replace:
TryReplaceStyleBehaviors(GetStyleBehaviors(sourceCollection.Owner), e.OldItems, e.NewItems, true);
break;
case NotifyCollectionChangedAction.Move:
if (e.OldStartingIndex == e.NewStartingIndex)
{
break;
}
int difference = e.OldStartingIndex - e.NewStartingIndex;
int id;
FreezableCollection <Behavior> styleBehaviors = GetStyleBehaviors(sourceCollection.Owner);
foreach (Behavior item in e.OldItems)
{
id = item.Id;
item.Id -= difference;
foreach (Behavior styleItem in styleBehaviors)
{
if (styleItem.Id == id)
{
styleItem.Id = item.Id;
}
}
}
void updateId(int startIndex, int length)
{
int count = length + startIndex;
for (int i = startIndex; i < count; i++)
{
id = sourceCollection[startIndex].Id;
sourceCollection[startIndex].Id += startIndex + 1;
foreach (Behavior styleItem in styleBehaviors)
{
if (styleItem.Id == id)
{
styleItem.Id = sourceCollection[startIndex].Id;
}
}
}
}
int _startIndex;
if (e.NewStartingIndex < e.OldStartingIndex)
{
_startIndex = e.NewStartingIndex + e.OldItems.Count;
updateId(_startIndex, e.OldStartingIndex + e.OldItems.Count - _startIndex + 1);
}
else
{
_startIndex = e.OldStartingIndex;
updateId(_startIndex, e.NewStartingIndex - _startIndex + 1);
}
break;
default:
break;
}
}
static int GetId(BehaviorBindingCollection sourceCollection) => sourceCollection.Count == 1 ? 1 : sourceCollection[sourceCollection.Count - 1].Id + 1;
/// <summary>
/// Provides a secure method for setting the Behaviors property.
/// This dependency property indicates ....
/// </summary>
private static void SetBehaviors(DependencyObject d, BehaviorBindingCollection value)
{
d.SetValue(BehaviorsPropertyKey, value);
((INotifyCollectionChanged)value).CollectionChanged += CollectionChanged;
}
public static void SetStyleBehaviors(DependencyObject obj, BehaviorBindingCollection value) => obj.SetValue(StyleBehaviorsProperty, value);
