public void Remove(T item)
{
//Before a change is about to happen we have to check if any subscriber wants to reject the change
var beforeRemove = new RejectableEventArgs_Subclass <T>(Operation.Remove, item, internalStorage.Count);
OnBeforeChange(beforeRemove);
// If the wanted item to remove is not on the list then throw InvalidOperationExeption
if (Contains(item))
{
//If change is rejected then throw OperationRejectedExeption
if (beforeRemove.IsOperationRejected == false)
{
internalStorage.Remove(item);
OnChanged(this, new ListChangedEventArgs <T>(Operation.Remove, item, internalStorage.Count));
}
else
{
throw new OperationRejectedException("You can not remove this item!");
}
}
else
{
throw new InvalidOperationException("This item is not on the list!");
}
}
/// <summary>
/// Instead of using the real add method, this methods allows you to explore what you are able to add and not, without handling exceptions.
/// </summary>
/// <param name="item"></param>
/// <returns>bool</returns>
public bool TryAdd(T item)
{
var tryAdd = new RejectableEventArgs_Subclass <T>(Operation.Add, item, internalStorage.Count);
OnBeforeChange(tryAdd);
if (tryAdd.IsOperationRejected == false)
{
internalStorage.Add(item);
return(true);
}
else
{
return(false);
}
}
//Methods to manipulate the internal storage
public void Add(T item)
{
//Before a change is about to happen we have to check if any subscriber wants to reject the change
var beforeAdd = new RejectableEventArgs_Subclass <T>(Operation.Add, item, internalStorage.Count);
OnBeforeChange(beforeAdd);
//Check if any subscriber rejected the change, if not, go on and make the change
if (beforeAdd.IsOperationRejected == false)
{
internalStorage.Add(item);
OnChanged(this, new ListChangedEventArgs <T>(Operation.Add, item, internalStorage.Count));
}
else
{
throw new OperationRejectedException("You can not add this item!");
}
}
/// <summary>
/// Instead of using the real remove method, this methods allows you to explore what you are able to remove and not, without handling exeptions.
/// </summary>
/// <param name="item"></param>
/// <returns>bool</returns>
public bool TryRemove(T item)
{
var tryRemove = new RejectableEventArgs_Subclass <T>(Operation.Remove, item, internalStorage.Count);
OnBeforeChange(tryRemove);
if (Contains(item))
{
if (tryRemove.IsOperationRejected == false)
{
internalStorage.Remove(item);
return(true);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
protected virtual void OnBeforeChange(RejectableEventArgs_Subclass <T> args)
{
BeforeChange?.Invoke(this, args);
}