public int GetVisibleItemsCount()
{
var layoutManager = (LinearLayoutManager)_recyclerView.GetLayoutManager();
var firstVisiblePosition = layoutManager.FindFirstCompletelyVisibleItemPosition();
var lastVisiblePosition = layoutManager.FindLastCompletelyVisibleItemPosition();
return(lastVisiblePosition - firstVisiblePosition);
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == FastGridView.ItemsSourceProperty.PropertyName)
{
CalculateLayoutRects();
if (_adapter != null && Element != null)
{
_adapter.Items = Element.ItemsSource;
}
_recyclerView?.GetLayoutManager()?.ScrollToPosition(0);
}
else if (e.PropertyName == VisualElement.WidthProperty.PropertyName || e.PropertyName ==
FastGridView.ItemTemplateSelectorProperty.PropertyName)
{
_recyclerView?.GetRecycledViewPool()?.Clear();
_recyclerView?.SetAdapter(null);
_recyclerView?.SetAdapter(_adapter);
CalculateLayoutRects();
_adapter?.NotifyDataSetChanged();
}
else if (e.PropertyName == FastGridView.IsScrollEnabledProperty
.PropertyName)
{
Device.BeginInvokeOnMainThread(() => {
if (_recyclerView != null && Element != null)
{
_recyclerView.Enabled = Element.IsScrollEnabled;
}
});
}
else if (e.PropertyName ==
FastGridView.IsRefreshingProperty.PropertyName)
{
if (_refresh != null && Element != null)
{
_refresh.Refreshing = Element.IsRefreshing;
}
}
else if (e.PropertyName == FastGridView
.IsPullToRefreshEnabledProperty.PropertyName)
{
if (_refresh != null && Element != null)
{
_refresh.IsPullToRefreshEnabled = Element.IsPullToRefreshEnabled;
}
}
else if (e.PropertyName == FastGridView.RefreshTopOffsetProperty
.PropertyName)
{
if (_refresh != null && Element != null)
{
if (Element.RefreshTopOffset != -1)
{
_refresh.Refreshing = false;
var size = (int)(Element.RefreshTopOffset * _density);
_refresh.SetProgressViewOffset(true, 0, size);
_refresh.Refreshing = Element.IsRefreshing;
}
}
}
else if (e.PropertyName == FastGridView.LoadMoreCommandProperty
.PropertyName)
{
Device.BeginInvokeOnMainThread(() => {
if (_scrollListener != null)
{
_scrollListener.EnableLoadMore = Element?.LoadMoreCommand != null;
}
});
}
}
