public bool OnItemLongClick(AWidget.AdapterView parent, AViews.View view, int position, long id)
{
object selectedItem = null;
//if (_element.ItemsSource.GetType().GetInterfaces().Any(x => x == typeof(IGroupedOrderable)))
if (element.ItemsSource is IGroupedOrderableCollection grouped)
{
selectedItem = grouped.GetItemFromFlatIndex(id);
}
else
{
selectedItem = ((IList)element.ItemsSource)[(int)id];
}
// Creating drag state
DragItem dragItem = new DragItem(NormalizeListPosition(position), view, selectedItem);
// Creating a blank clip data object (we won't depend on this)
var data = ClipData.NewPlainText(string.Empty, string.Empty);
// Creating the default drag shadow for the item (the translucent version of the view)
// NOTE: Can create a custom view in order to change the dragged item view
AViews.View.DragShadowBuilder shadowBuilder = new AViews.View.DragShadowBuilder(view);
// Setting the original view cell to be invisible
view.Visibility = AViews.ViewStates.Invisible;
// NOTE: this method is introduced in Android 24, for earlier versions the StartDrag method should be used
view.StartDragAndDrop(data, shadowBuilder, dragItem, 0);
return(true);
}
private int InsertOntoView(AViews.View view, DragItem item)
{
var positionEntered = GetListPositionForView(view);
var correctedPosition = positionEntered;
// If the view already has a translation, we need to adjust the position
// If the view has a positive translation, that means that the current position
// is actually one index down then where it started.
// If the view has a negative translation, that means it actually moved
// up previous now we will need to move it down.
if (view.TranslationY > 0)
{
correctedPosition += 1;
}
else if (view.TranslationY < 0)
{
correctedPosition -= 1;
}
// If the current index of the dragging item is bigger than the target
// That means the dragging item is moving up, and the target view should
// move down, and vice-versa
var translationCoef = item.Index > correctedPosition ? 1 : -1;
// We translate the item as much as the height of the drag item (up or down)
var translationTarget = view.TranslationY + (translationCoef * item.View.Height);
ObjectAnimator anim = ObjectAnimator.OfFloat(view, "TranslationY", view.TranslationY, translationTarget);
anim.SetDuration(100);
anim.Start();
return(correctedPosition);
}