/// <summary>Observe CollectionChanged:Replace.</summary>
public static IObservable <OldNewPair <T[]> > ObserveReplaceChangedItems <T>(this ReadOnlyObservableCollection <T> source)
{
var result = source.CollectionChangedAsObservable()
.Where(e => e.Action == NotifyCollectionChangedAction.Replace)
.Select(e => new OldNewPair <T[]>(e.OldItems.Cast <T>().ToArray(), e.NewItems.Cast <T>().ToArray()));
return(result);
}
/// <summary>Observe CollectionChanged:Reset.</summary>
public static IObservable <Unit> ObserveResetChanged <T>(this ReadOnlyObservableCollection <T> source)
{
var result = source.CollectionChangedAsObservable()
.Where(e => e.Action == NotifyCollectionChangedAction.Reset)
.Select(_ => new Unit());
return(result);
}
/// <summary>Observe CollectionChanged:Replace and take single item.</summary>
public static IObservable <OldNewPair <T> > ObserveReplaceChanged <T>(this ReadOnlyObservableCollection <T> source)
{
var result = source.CollectionChangedAsObservable()
.Where(e => e.Action == NotifyCollectionChangedAction.Replace)
.Select(e => new OldNewPair <T>((T)e.OldItems[0], (T)e.NewItems[0]));
return(result);
}
/// <summary>Observe CollectionChanged:Remove and take single item.</summary>
public static IObservable <T> ObserveRemoveChanged <T>(this ReadOnlyObservableCollection <T> source)
{
var result = source.CollectionChangedAsObservable()
.Where(e => e.Action == NotifyCollectionChangedAction.Remove)
.Select(e => (T)e.OldItems[0]);
return(result);
}
/// <summary>Observe CollectionChanged:Add.</summary>
public static IObservable <T[]> ObserveAddChangedItems <T>(this ReadOnlyObservableCollection <T> source)
{
var result = source.CollectionChangedAsObservable()
.Where(e => e.Action == NotifyCollectionChangedAction.Add)
.Select(e => e.NewItems.Cast <T>().ToArray());
return(result);
}
public HohoemaListingPageItemBase()
{
ImageUrls = new ReadOnlyObservableCollection <string>(ImageUrlsSource);
_Disposer = ImageUrls.CollectionChangedAsObservable()
.Subscribe(_ =>
{
OnPropertyChanged(nameof(FirstImageUrl));
OnPropertyChanged(nameof(HasImageUrl));
OnPropertyChanged(nameof(IsMultipulImages));
});
}
public TodoApp()
{
_todoItems = new ObservableCollection <TodoItem>();
AllTodoItems = new ReadOnlyObservableCollection <TodoItem>(_todoItems);
ActiveTodoItems = AllTodoItems.ToFilteredReadOnlyObservableCollection(x => !x.Completed.Value).AddTo(_disposables);
CompletedTodoitems = AllTodoItems.ToFilteredReadOnlyObservableCollection(x => x.Completed.Value).AddTo(_disposables);
IsCompletedAllItems = AllTodoItems.ObserveElementProperty(x => x.Completed)
.ToUnit()
.Merge(AllTodoItems.CollectionChangedAsObservable().ToUnit())
.Throttle(TimeSpan.FromMilliseconds(10))
.Select(_ => AllTodoItems.Count != 0 && AllTodoItems.All(x => x.Completed.Value))
.ToReadOnlyReactivePropertySlim()
.AddTo(_disposables);
}
