private static void TryStartPivotHeaderAnimation(Pivot pivot, object NewItem, object OldItem)
{
if (NewItem == null)
{
return;
}
var NewIndex = -1;
var OldIndex = -1;
if (pivot.ContainerFromItem(OldItem) is PivotItem oldContainer)
{
OldIndex = pivot.IndexFromContainer(oldContainer);
}
if (pivot.ContainerFromItem(NewItem) is PivotItem newContainer)
{
NewIndex = pivot.IndexFromContainer(newContainer);
}
if (NewIndex >= 0)
{
var name = GetName(pivot);
var Headers = pivot.VisualTreeFindAll <PivotHeaderPanel>();
var Header = Headers.FirstOrDefault(c => c.Name == "Header");
var StaticHeader = Headers.FirstOrDefault(c => c.Name == "StaticHeader");
var newIndicator = GetPivotHeaderIndicator(Header, name, NewIndex);
var newStaticIndicator = GetPivotHeaderIndicator(StaticHeader, name, NewIndex);
if (OldIndex >= 0)
{
var oldIndicator = GetPivotHeaderIndicator(Header, name, OldIndex);
var oldStaticIndicator = GetPivotHeaderIndicator(StaticHeader, name, OldIndex);
if (Header != null && newIndicator != null && oldIndicator != null)
{
TryStartPivotHeaderAnimation(Header, newIndicator, oldIndicator, GetIsScaleEnabled(pivot));
}
if (StaticHeader != null && newStaticIndicator != null && oldStaticIndicator != null)
{
TryStartPivotHeaderAnimation(StaticHeader, newStaticIndicator, oldStaticIndicator, GetIsScaleEnabled(pivot));
}
}
else
{
if (newIndicator != null)
{
newIndicator.Visibility = Visibility.Visible;
}
if (newStaticIndicator != null)
{
newStaticIndicator.Visibility = Visibility.Visible;
}
}
}
}