Menus of the low level net editor

File Menu

The items on the File Menu are: Open, Reload, Save, Save as, Delete Net, Export to Postscript, and Quit.
Open
Opens the file browser to select a low level Petri net.

Reload
Reloads the low level Petri net.

Save
Saves the contents of the net editor to the file whose name is displayed underneath the menu bar).

Save as
Opens the file browser to save the contents of the net editor to a file.

Delete Net
Clears the editor (i.e, deletes the current net but not the file).

Export to PostScript
All Objects
A file browser is opened to choose the name of a file to which all the objects (places, transitions, arcs, currently displayed kinds of annotations and comments) are exported in PostScript format. The net examples in the appendix have been produced in this way.

Selection
A file browser is opened to choose the name of a file to which all the currently selected objects (places, transitions, arcs, currently displayed kinds of annotations and comments) are exported in PostScript format.

Entire Screen
A file browser is opened to choose the name of a file to which all the currently selected objects (places, transitions, arcs, currently displayed kinds of annotations and comments) are exported in PostScript format.

Quit
Closes the net editor. If there are unsaved changes a dialog box asks whether or not these changes should be saved.

Edit Menu

The items on the Edit Menu are: New Place, New Transition, New Edge, Delete Elements, and Select All.
New Place
Switches the mode of the net editor to place insertion. The shape of the cursor changes to an internal place without a marking. The user can create such a new place by clicking at the desired position of the drawing canvas.

New Transition
Switches the mode of the net editor to transition insertion. The shape of the cursor changes to a transition. The user can create such a new transition by clicking at the desired position of the drawing canvas.

New Arc
Switches the mode of the net editor to arc insertion. The user can determine the start node and afterwards the end node of the arc by clicking at the desired place (transition) and transition (place, resp.).

Delete Elements
Deletes the currently selected elements.

Select All
Selects all objects (places, transitions and their edges together with their annotations) of the net.
Note: A selection can be de-selected by a click with the middle mouse button at any position of the drawing canvas.

Create Comment
Switches the mode of the net editor to comment insertion. The user can create a comment by clicking at the desired place. A dialog box is opened to edit the text.

Action Menu

The items on the Action Menu are: Active Transition, Reset to Initial Marking, Animate, and Show Reference.
Active Transition
Coloures all currently enabled transitions yellow. The mode can be exited by pressing the Esc key.

Reset to Initial Marking
Resets the marking to the initial marking from which a new simulation of the net can be started.

Animate
Switches the mode of the net editor so that an automatic simulation is started. During the simulation all currently enabled transitions are coloured yellow. One of them is chosen randomly and is executed. The surrounding arcs are coloured green to show the token flow. The mode can be exited by pressing the Esc key.

Show Reference
If the low level net is a Petri box that has been compiled out of the B(PN)² program via an M-net the correspondence between a place of the net and a point in the control flow of the B(PN)² program or between a transition in the net and actions in the B(PN)² program can be demonstrated. The mode of the net editor is switched so that the corresponding text segment is highlighted in aquamarine if the user clicks on a transition or a place. The mode can be left by pressing the Esc key.

Option Menu

The items on the Option Menu are: Display Names, Display Meanings, Gridding, Show Invisible Arcs, Highlight Execution, and Zoom.
Display Names
Chooses whether or not the names of places and transitions are displayed.

Display Meanings
Chooses whether or not the meanings of places and transitions are displayed.

Gridding
Chooses whether or not places and transitions have to be aligned along an underlying grid.

Show Invisible Arcs
Chooses whether or not invisible arcs are displayed. An invisible flag is (can be) set by the compiler 'B(PN)² => M-net' ('PBC => LL Net', resp.) for arcs beetwen the data boxes of the net and the control flow part of the net to enhance the readability of the constructed nets.

Highlight Execution
If the low level net is a Petri box that has been compiled out of the B(PN)² program via an M-net, the correspondence between a place in the net and a point in the control flow of the B(PN)² program or between a transition in the net and actions in the B(PN)² program can be demonstrated. The mode of the net editor is switched so that if a transition is executed, the corresponding text segment is highlighted aquamarine in the B(PN)² editor.

Zoom
Switches amongst different zoom factors.

Note: The status of a place is always displayed by appropriate colours. Entry places are coloured green, exit places are coloured red and internal places are uncoloured.

Help

Info
Shows an about box.