/// <summary>
/// Monitors the specified properties.
/// </summary>
/// <typeparam name="TSource">The type of the source.</typeparam>
/// <param name="command">The command.</param>
/// <param name="source">The source.</param>
/// <param name="properties">The properties to monitor.</param>
/// <returns>The original command.</returns>
public static IDelegateCommand Observe <TSource>(this IDelegateCommand command, TSource source, params Expression <Func <TSource, Object> >[] properties)
where TSource : INotifyPropertyChanged
{
Ensure.That(properties).Named(() => properties).IsNotNull();
if (properties.Any())
{
var observer = PropertyObserver.For(source);
foreach (var prop in properties)
{
observer.Observe(prop);
}
command.AddMonitor(observer);
}
else
{
var observer = PropertyObserver.ForAllPropertiesOf(source);
command.AddMonitor(observer);
}
return(command);
}