Directed graph editor derived from drawtool
graphdraw ['X-params'] [file]
graphdraw implements a graph (node/edge) editor. graphdraw adds two new graphical objects to idraw/drawtool: an elliptical shaped node and a directed edge represented as an arrow line. Two new tools to create these objects are provided at the bottom of the toolbar. The Node tool (selectable by the 'N' key) takes a single mouse click and creates a new graph node at the click location. The Edge tool (selectable by the 'E' key) lets you drag a line to create a new graph edge. If an edge is drawn from or to an existing node, it will connect itself to the node(s) and maintain that connectivity during any later movement of nodes or edges. The Move tool will move edges or nodes, rubberbanding the rest of the graph, and redrawing any connected edges to maintain graph connectivity and edge alignment.
Nodes contain a (initially empty) text string which can be edited by applying the Alter tool to a node. A single click on a node while on the Alter tool will create a text cursor, possibly within an existing text string, and allow editing of the text via the usual Emacs editing commands. A click outside the text terminates editing and causes the new text to be centered within the node.
For Node and Edge objects, the Selection highlight mechanism has also been changed from the usual drawing of "handles" around a graphical object to a red foreground color. When Nodes or Edges are selected, they turn red instead of handles being drawn around them.
graphdraw documents are saved/restored in a readable text file. Some of the tokens used in the text file are specific to graphdraw (and possibly any program derived from graphdraw). graph drawings can be exported to other idraw/drawtool applications via the "Export Graphic" command (under the File menu). This generates Postscript in a format that idraw can read back in, and programs like drawtool can import via "Import Graphic" (under the file menu).
A Tools menu has been added to the set of pull-down menus to allow switching between a graph editing toolbar and a generic graphics editing toolbar.
drawtool, idraw
http://www.ivtools.org/ivtools/graphdraw.html