Drawing
The rightmost sub window of the system editor is used for drawing
automata. There are currently four drawing tools named
Select, Location, Transition, and
Nail represented by the buttons in the tool bar.
- Select tool: The select tool is used to select, move, modify
and delete elements. Elements can be selected by clicking on them or
by dragging a rubber band arround one or more elements. Elements can
be added or removed from a selection by holding down the control key
while clicking on the element. The current selection can be moved by
dragging them with the mouse. Double clicking an element brings up the
editor for that element. Right clicking an element or a selection of
elements brings up the pop-up menu. It is possible to change the
source and target of a transition by moving the mouse to the beginning
or end of a transition until a small circle appears. Drag this circle
to a new location in order to change the source or target of the
transition.
- Location tool: The location tool is used to add new
locations. Simply click with the left mouse button in order to add a
new location.
- Transition tool: The transition tool is used to add new
transitions between locations. Start the transition by clicking on the
source location, then click in order to place nails and finally click
the target location. The operation can be cancelled by pressing the
middle or right mouse button.
- Nail tool: The nail tool is used to add new nails to a
transition. Simply click and drag anywhere on a transition to add and
place a new nail.
For users with a three button mouse, the middle mouse button can be
used to create new elements. The editor automatically chooses the
correct tool: Clicking on an empty spot creates a new location,
clicking on a location create a new transition and clicking on a
transition creates a new nail. With this feature it is possible to use
the functionallity of all four tools without having to select the
tools directly.