public static IDisposable SubscribeOnScrollEnd(this MvxRecyclerView recyclerView, IMvxAsyncCommand loadElements, Func <bool> canExecute)
{
var propertyChanged = Observable.FromEventPattern <EventHandler <View.ScrollChangeEventArgs>, View.ScrollChangeEventArgs>(
h => recyclerView.ScrollChange += h, h => recyclerView.ScrollChange -= h);
return(propertyChanged
.Select(_ => recyclerView.GetLayoutManager() as LinearLayoutManager ??
recyclerView.GetLayoutManager() as GridLayoutManager)
.Where(lm => lm != null && canExecute() &&
(lm.StackFromEnd
? lm.FindFirstVisibleItemPosition() <= 10
: lm.FindFirstVisibleItemPosition() + lm.ChildCount >= lm.ItemCount - 10))
.Throttle(TimeSpan.FromMilliseconds(100))
.ObserveOn(Application.SynchronizationContext)
.Subscribe(
async _ => await loadElements.ExecuteAsync(),
exception =>
Mvx.Resolve <IToastSerivce>().ShowByResourceId(exception.Message)));
}
public override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
ViewModel.PropertyChanged += (o, e) =>
{
if (e.PropertyName == nameof(ViewModel.ChatMessages) && ViewModel.ChatMessages?.Count > 0)
{
var _scroller = new ToEndSmoothScroller(Android.App.Application.Context);
_scroller.TargetPosition = ViewModel.ChatMessages.Count - 1;
_chatListView.GetLayoutManager().StartSmoothScroll(_scroller);
}
};
}