public static void GetVisibleItems <T>(this IEnumerable <T> items, FrameworkElement viewport, Orientation orientation, out List <T> beforeItems, out List <T> visibleItems, out List <T> afterItems) where T : FrameworkElement
{
beforeItems = new List <T>();
visibleItems = new List <T>();
afterItems = new List <T>();
ExtensionMethods.VisibleSearchMode visibleSearchMode = ExtensionMethods.VisibleSearchMode.Before;
foreach (T obj in items)
{
switch (visibleSearchMode)
{
case ExtensionMethods.VisibleSearchMode.Before:
if (ExtensionMethods.TestVisibility((FrameworkElement)obj, viewport, orientation, false))
{
beforeItems.Add(obj);
break;
}
else
{
visibleItems.Add(obj);
visibleSearchMode = ExtensionMethods.VisibleSearchMode.During;
break;
}
case ExtensionMethods.VisibleSearchMode.During:
if (ExtensionMethods.TestVisibility((FrameworkElement)obj, viewport, orientation, true))
{
visibleItems.Add(obj);
break;
}
else
{
afterItems.Add(obj);
visibleSearchMode = ExtensionMethods.VisibleSearchMode.After;
break;
}
default:
afterItems.Add(obj);
break;
}
}
}
public static IEnumerable <T> GetVisibleItems <T>(this IEnumerable <T> items, FrameworkElement viewport, Orientation orientation) where T : FrameworkElement
{
return(Enumerable.TakeWhile <T>(Enumerable.SkipWhile <T>(items, (Func <T, bool>)(item => ExtensionMethods.TestVisibility((FrameworkElement)item, viewport, orientation, false))), (Func <T, bool>)(item => ExtensionMethods.TestVisibility((FrameworkElement)item, viewport, orientation, true))));
}