Version 5.0 The LEDA User Manual

17.6 Graph Windows ( GraphWin )
1. Definition
GraphWin combines the two types graph and window and forms a bridge between the
graph data types and algorithms and the graphics interface of LEDA. GraphWin can
easily be used in LEDA programs for constructing, displaying and manipulating graph
and for animating and debugging graph algorithms.
• The user interface of GraphWin is simple and intuitive. When clicking a mouse
button inside the drawing area a corresponding default action is performed that
can be redefined by users. With the initial default settings, the left mouse button
is used for creating and moving objects, the middle button for selecting objects,
and the right button for destroying objects. A number of menues at the top of the
window give access to graph generators, modifiers, basic algorithms, embeddings,
setup panels, and file input and output.
• Graphwin can display and manipulate the data associated with the nodes and edges
of LEDA’s parameterized graph type GRAP H < vtype, etype >. When a Graph-
Win is opened for such a graph the associated node and edge labels of type vtype
and etype can be displayed and edited.
• Most of the actions of GraphWin can be customized by modifying or extending the
menues of the main window or by defining call-back functions. So the user can
define what happens if a node or edge is created, selected, moved, or deleted.
• Graphwin offers a collection of graph generators, modifiers and tests. The generators
include functions for constructing random, planar, complete, bipartite, grid graph,
connected graph, biconnected, graph . . .
There are also methods for modifying existing graph (e.g. by removing or adding a
certain set of edges) to fit in one of these categories and for testing whether a given
graph is planar, connected, bipartite . . .
• The standard menu includes a choice of fundamental graph algorithms and basic
embedding algorithms.
For every node and edge of the graph GraphWin maintains a set of parameters.
With every node is associated the following list of parameters. Note that for every parameter
there are corresponding set and get operations (gw.set param() and gw.get param)
where param has to be replaced by the corresponding parameter name.
position: the position of the node (type point),