public CreatingLineInformation(VisualUnit first, VisualUnit last)
{
FirstUnit = first;
LastUnit = last;
Drawing = new DrawingVisual();
FirstUnit.PositionChanged += UnitPositionChanged;
LastUnit.PositionChanged += UnitPositionChanged;
}
public CreatingLineInformation(VisualUnit first) : this(first, new VisualThumb(first.Position))
{
}