protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == nameof(Element.Position) && _position != Element.Position && !Controller.IgnorePositionUpdates)
{
_physicalLayout.ScrollToPosition(Element.Position);
}
if (e.PropertyName == nameof(Element.ItemsSource))
{
InitializeAdapter();
}
base.OnElementPropertyChanged(sender, e);
}
void Initialize()
{
// cache hit? Check if the view page is already created
RecyclerView recyclerView = Control;
if (recyclerView != null)
{
return;
}
// cache miss
recyclerView = new RecyclerView(Context);
SetNativeControl(recyclerView);
// layoutManager
recyclerView.SetLayoutManager(
layout: _physicalLayout = new PhysicalLayoutManager(
context: Context,
virtualLayout: new VirtualLayoutManager()
)
);
// swiping
recyclerView.AddOnScrollListener(
new OnScrollListener(
onDragStart: () => { },
onDragEnd: () => {
var velocity = _physicalLayout.Velocity;
var target = velocity.X > 0 ?
_physicalLayout.VisiblePositions().Max() :
_physicalLayout.VisiblePositions().Min();
_physicalLayout.ScrollToPosition(target);
},
onScrollSettled: () => {
var visiblePositions = _physicalLayout.VisiblePositions().ToArray();
_position = visiblePositions.Single();
OnPositionChanged();
OnItemChanged();
},
visibleViewCount: () => _physicalLayout.VisiblePositions().Count()
)
);
// adapter
InitializeAdapter();
}