private Digit findAdjacentMathDigits(LogicalDirection direction)
{
Digit expr = null;
if (Selection.Text.Length == 0)
{
DependencyObject dpObj = CaretPosition.GetAdjacentElement(
direction);
// is it contained in BlockUIContainer?
expr = CaretPosition.GetAdjacentElement(
direction) as Digit;
// is it onctained in a InlineUIContainer?
if (expr == null)
{
InlineUIContainer uiWrapper =
CaretPosition.GetAdjacentElement(
direction) as InlineUIContainer;
if (uiWrapper != null)
{
expr = uiWrapper.Child as Digit;
}
}
}
return(expr);
}
