A compound box is a box which contains a set of other boxes. Compound boxes
allow a set of boxes to be bracketed as a single functional unit. They behave
in the same way as all other boxes when they are being drawn and manipulated,
but can be opened to reveal a new window in which further boxes may be
drawn. The set of boxes which comprise the compound may be drawn in this
window in exactly the same way as boxes were drawn on the compound's parent's
Any model can actually be thought of as a compound box, and opening a
compound reveals a new window much like the main window. However, the
window associated with a compound differs from the main window in one
important way: it contains "virtual" boxes, drawn with dotted lines,
representing those boxes to which the compound is externally linked.
Arrows may be drawn to and from these external objects, enabling
boxes within the compound to communicate with those outside of it.
There are several things which you might want to do with compounds but
which cannot as yet be done. It is not possible, for example, to
"rubber-band" a set of boxes and transform them into a compound. Conversely,
it is not possible to "explode" a compound, so that all boxes within a
compound return to the compound's parent. However, it is possible to cut and
paste boxes between compounds (just as you can cut and paste subobjects
between any pair of boxes of the same class). Since a model can be thought of
as a compound box, this facility means that you can cut
objects from the main window and place them in a compound, or you can cut them
from a compound and place them on the main window. It is also possible to
cut and paste objects between different models.
A window displaying a compound box has an Initial Contents tab which
allows the user to add and delete boxes and arrows and to move boxes. Once the
Initial Contents tab has been selected the following operations may be performed.
- To add a box: simply left-click on the appropriate box type on the
then move the mouse pointer to
the intended location on the window and left-click again. The new box
should appear at the selected location.
- To add arrows: left-click on the
selected arrow type in the toolbar, then left-click on the box from
which the arrow will lead then, holding the left mouse button down,
drag to the box where it should
terminate. An arrow of the selected type will appear, linking the
- To open a box revealing its contents and properties: double-click on it with the left mouse
- To select a box: single click on it with the left mouse button.
- To move a box: select it and drag with the left mouse button held
- To cut a box, i.e. to delete it and place it on the windows clipboard:
select the box and then either click on the cut button in the toolbar, or select the Edit->Cut
menu item. It is not possible to delete a box without placing it on the clipboard.
- To copy a box onto the windows clipboard without deleting it:
select the box and then either click on the copy button in the toolbar, or select the Edit->Copy
- To move a box from one compound to another: cut or copy the box onto the clipboard, open
the compound into which the box is to be pasted, select this compound's Initial Contents tab
and then either click on the toolbar's paste button, or select the Edit->Paste menu item.
The pasted box will appear at same position as it had in the compound
from which it was cut or copied. If you do not
immediately see the pasted box it may be because it is outside the window into
which you have pasted it. Expanding or maximising the window should make the
box visible. The compound into which the box is pasted can be in a different model to
that from which it was cut or copied.
- To rename a box: select it and then either type Ctrl-R or select the Edit->Rename menu item.
An edit box then appears into which the box's new name may entered. To validate the name either
type return or left click with the mouse on a point outside the edit box.