The type editor for node and edge types can be found above the rule editor.
In the beginning, no types are defined and at least one node and one edge
type have to be defined to draw nodes and edges.
The type editor has a limited set of elementary graphics to represent nodes and edges.
Nodes may be shaped as rectangles with / without rounded corners,
ovals and circles. Edges may be solid, dotted or dashed lines. Both
nodes and edges may have different colours.
A type name may be added to identify a
graph object's type but is not necessary. For example, there might be defined the
node types red rectangle, blue rectangle, red circle with type
name City and red rectangle with type name City. These are
four different node types. The type of an object has to be defined before actually
drawing the object. A type is defined by clicking on the graphical Node Type (or Edge Type)
symbol and selecting a graphical shape and/or colour in the context menu of colours and shapes/styles.
Then the type name must be entered
into the Node Type or Edge Type text field.
Even if the type name is left empty,
at least the return key must be pressed in the Node/Edge Type text field. Then, the
new type is stored in the Node Type or Edge Type list.
It can be accessed by mouse click whenever a new object of
this type is to be drawn. The current type is indicated by the graphical symbol next
to the Node/Edge Type text field and the name inside the text field.
In the graphical editors, the type name (if any) is shown inside the node shape or next to the middle point of an edge.
The redefinnition of a node or an edge type is possible by clicking on the graphical Node Type (or Edge Type) symbol and selecting
item Redefine. Now, the name or graphical representation
of current type may be changed. At least the return key must be pressed in the text field to accept the type changes.
NOTE: Do not forget to deselect item Redefine, if you want create a new node/edge type.
A node or an edge type can be deleted by clicking on the graphical Node Type (or Edge Type) symbol and selecting
item Delete. If current type was already used for typing,
a warning dialog appears to ask you for confirmation
since all objects of this type and possibly adjacent edges
will be deleted, too.
Otherwise, the type will be deleted immediately.
A type palette on the right of the grammar editor makes easier selecting node / edge types and editing graphs.