The Decorative line graphical schema item is designed for drawing lines and arrows and for connecting other items. A Decorative line is automatically redrawn when the relative positions of the items it joins change. You cannot change the drawing algorithm, you can only move medial line points. If you move medial segments manually, the application attempts to preserve your changes during the next automatic redrawings of the line.
When drawing a line, an application also attempts to create the shortest path consisting of vertical and horizontal line segments that do not cross other schema items.
Medial segments of decorative lines can be strictly vertical or strictly horizontal. Decorative line bends are rounded, which clarifies line directions at intersection points.
Automatic drawing is used only for the lines that connect two schema items.
When you add a decorative line, the arrow direction is determined by the ratio of the sides of the rectangle that you select when you add a line: if the height is greater than the width, the vertical direction is selected, otherwise the horizontal direction is selected.
Breaking decorative lines into segments is not grid-based.