void UpdateNativeSelection()
{
var mode = ItemsView.SelectionMode;
ItemsViewAdapter.ClearNativeSelection();
switch (mode)
{
case SelectionMode.None:
return;
case SelectionMode.Single:
var selectedItem = ItemsView.SelectedItem;
ItemsViewAdapter.MarkNativeSelection(selectedItem);
return;
case SelectionMode.Multiple:
var selectedItems = ItemsView.SelectedItems;
foreach (var item in selectedItems)
{
ItemsViewAdapter.MarkNativeSelection(item);
}
return;
}
}
void UnsubscribeCollectionItemsSourceChanged(ItemsViewAdapter <ItemsView, IItemsViewSource> oldItemViewAdapter)
{
if (oldItemViewAdapter?.ItemsSource is ObservableItemsSource oldObservableItemsSource)
{
oldObservableItemsSource.CollectionItemsSourceChanged -= CollectionItemsSourceChanged;
}
}
int GetIndexFromTemplatedCell(global::Android.Views.View view)
{
int itemIndex = -1;
if (view is ItemContentView templatedCell)
{
var bContext = templatedCell?.Element?.BindingContext;
itemIndex = ItemsViewAdapter.GetPositionForItem(bContext);
}
return(itemIndex);
}
int GetCarouselViewCurrentIndex(int index)
{
var centeredView = this.GetCenteredView();
if (centeredView is ItemContentView templatedCell)
{
var bContext = templatedCell?.Element?.BindingContext;
index = ItemsViewAdapter.GetPositionForItem(bContext);
}
else
{
return(-1);
}
return(index);
}
protected override int DetermineTargetPosition(ScrollToRequestEventArgs args)
{
if (args.Mode == ScrollToMode.Element)
{
return(ItemsViewAdapter.GetPositionForItem(args.Item));
}
if (!Carousel.Loop)
{
return(args.Index);
}
if (_carouselViewLoopManager == null)
{
return(-1);
}
var carouselPosition = GetCarouselViewCurrentIndex(Carousel.Position);
var getGoIndex = _carouselViewLoopManager.GetGoToIndex(this, carouselPosition, args.Index);
return(getGoIndex);
}
public CarouselViewOnScrollListener(ItemsView itemsView, ItemsViewAdapter <ItemsView, IItemsViewSource> itemsViewAdapter, CarouselViewLoopManager carouselViewLoopManager) : base(itemsView, itemsViewAdapter, true)
{
_carouselView = itemsView as FormsCarouselView;
_carouselViewLoopManager = carouselViewLoopManager;
}