/// <summary>
/// Changes a field and notifies all registered receivers about a changed property,
/// if the value of its field has changed.
/// </summary>
/// <typeparam name="TField">The type of the field.</typeparam>
/// <param name="handler">The handler.</param>
/// <param name="field">The field.</param>
/// <param name="fieldValue">The field value.</param>
/// <param name="sender">The sender.</param>
/// <param name="propertyName">Name of the property.</param>
/// <returns>True, if the field has changed and therefore the value has been updated, false otherwise</returns>
public static bool ChangeAndNotify <TField>(this PropertyChangedEventHandler handler, ref TField field,
TField fieldValue, object sender, string propertyName)
{
if (!Equals(field, fieldValue))
{
field = fieldValue;
handler.Notify(sender, propertyName);
return(true);
}
return(false);
}
public static bool TryUpdateEnum <T>(this PropertyChangedEventHandler handler, INotifyPropertyChanged sender, ref T field, T value, [CallerMemberName] string propertyName = null) where T : Enum
{
if (field.Equals(value))
{
return(false);
}
var oldValue = field;
field = value;
handler.Notify(sender, oldValue, propertyName);
return(true);
}
internal static void Notify(
object sender,
NotifyCollectionChangedEventArgs change,
IScheduler scheduler,
PropertyChangedEventHandler propHandler,
NotifyCollectionChangedEventHandler colHandler)
{
if ((propHandler == null && colHandler == null) || change == null)
{
return;
}
switch (change.Action)
{
case NotifyCollectionChangedAction.Add:
case NotifyCollectionChangedAction.Remove:
propHandler.Notify(sender, CountPropertyChangedEventArgs);
propHandler.Notify(sender, IndexerPropertyChangedEventArgs);
colHandler.Notify(sender, change, scheduler);
break;
case NotifyCollectionChangedAction.Replace:
case NotifyCollectionChangedAction.Move:
propHandler.Notify(sender, IndexerPropertyChangedEventArgs);
colHandler.Notify(sender, change, scheduler);
break;
case NotifyCollectionChangedAction.Reset:
propHandler.Notify(sender, CountPropertyChangedEventArgs); // not sure if specialcasing is needed here.
propHandler.Notify(sender, IndexerPropertyChangedEventArgs);
colHandler.Notify(sender, change, scheduler);
break;
default:
throw new ArgumentOutOfRangeException();
}
}