public static bool IsAtRunBoundary(this TextPointer current, LogicalDirection direction)
{
int boundaryDistance = current.GetTextRunLength(direction);
int boundaryOffset = direction == LogicalDirection.Forward ? boundaryDistance : -boundaryDistance;
TextPointer boundary = current.GetPositionAtOffset(boundaryOffset);
return(boundary != null && current.IsAt(boundary));
}
public static Inline GetNextInlineInParagraph(this TextPointer current, LogicalDirection direction)
{
Func <Inline, bool> predicate = x =>
{
TextPointer elementBoundary = x.GetBoundary(direction);
var relativeDirection = elementBoundary.RelativeTo(current);
return(relativeDirection == direction || current.IsAt(elementBoundary));
};
var inlines = current.Paragraph?.Inlines;
if (inlines == null)
{
return(null);
}
var nextInline = direction == LogicalDirection.Forward
? inlines.FirstOrDefault(predicate)
: inlines.LastOrDefault(predicate);
return(nextInline);
}