/// <summary>
/// Removes the specified observer.
/// </summary>
/// <param name="observer">The observer.</param>
public void Remove(ICanExecuteChangedObserver observer)
{
if (observer == null)
{
throw new ArgumentNullException(nameof(observer));
}
if (!this.dictionary.TryGetValue(observer, out var handler))
{
return;
}
CommandManager.RequerySuggested -= handler;
this.dictionary.Remove(observer);
observer.RaisePropertyChanged();
}
/// <summary>
/// Removes the specified changedObserver.
/// </summary>
/// <param name="changedObserver">The changedObserver.</param>
public void Remove([NotNull] ICanExecuteChangedObserver changedObserver)
{
if (changedObserver == null)
{
throw new ArgumentNullException(nameof(changedObserver));
}
if (!this.observables.TryGetValue(changedObserver, out var handler))
{
return;
}
this.Update -= handler;
this.observables.Remove(changedObserver);
changedObserver.RaisePropertyChanged();
}
/// <summary>
/// Adds the specified observer.
/// </summary>
/// <param name="observer">The observer.</param>
/// <exception cref="ArgumentNullException">observer is null.</exception>
public void Add(ICanExecuteChangedObserver observer)
{
if (observer == null)
{
throw new ArgumentNullException(nameof(observer));
}
if (this.dictionary.TryGetValue(observer, out _))
{
return;
}
void Handler(object sender, EventArgs args) => observer.RaisePropertyChanged();
this.dictionary.Add(observer, Handler);
CommandManager.RequerySuggested += Handler;
}
/// <summary>
/// Adds the specified changedObserver.
/// </summary>
/// <param name="changedObserver">The changedObserver.</param>
public void Add([NotNull] ICanExecuteChangedObserver changedObserver)
{
if (changedObserver == null)
{
throw new ArgumentNullException(nameof(changedObserver));
}
if (this.observables.TryGetValue(changedObserver, out _))
{
return;
}
void Handler() => changedObserver.RaisePropertyChanged();
this.observables.Add(changedObserver, Handler);
this.Update += Handler;
}