Layout adjustment and boundary detection for a diagram

Diagrams (i.e. practical graphs where the nodes vary in shape and size) have been widely used in software engineering and information systems. A typical example is the UML diagram. Applying classical graph-drawing algorithms to practical graphs may result in overlapping nodes and/or node-edge intersections. This is because such algorithms were often originally designed for abstract graphs, where the nodes take up little or no space. This paper presents an approach for practical graph layout, layout adjustment for removing overlapping node images and node-edge intersections, and boundary detection for ensuring that a diagram fits in a viewing area