Link directions to other objects.
Hierarchy
Directions can be linked to objects above or below, in the Gamgi hierarchy. 
Pressing the button 
Below (the default), the 
Objects menu 
shows the classes of objects that can be owned by directions: Atom,
(the default), Orbital and Text. Pressing the button 
Above, the same 
menu shows the classes of objects that can own directions: Layer (the default), 
Assembly, Cell, Cluster, Molecule, Group and Plane.
Object
Gamgi expects users to identify first the direction or list of directions
and then the object to link. When the 
Direction entry is active 
and empty, clicking the mouse over an direction, on the current layer
(local selection), its identification is transported to the 
Direction entry. Gamgi is now expecting users to click on 
a object of the class currently selected in the 
Object menu. 
This object can be in a different layer or even in a different 
window (global selection).
To select a visible object in a different layer, in the same window, 
just press the mouse over the object, as if it was in the current 
layer. To select objects without visual representation, as layers,
press the mouse over the graphic area in the window, to create a menu 
with all the objects of that class in the window, which can then be 
selected. To select an object in a different window, with the mouse, 
use exactly the same procedure, in that window.
Link
Gamgi suppports only one type of linking mode for Cluster: 
Object.
The 
Object method links a direction to a single 
Object. 
When the 
Hierarchy is 
Above, the direction is unlinked from 
its current parent and linked to the object. When the direction is moved 
to a different layer, all its bonds to other objects are automatically 
removed. When the 
Hierarchy is 
Below, the object is unlinked 
from its current parent and linked to the direction. An error is issued 
when the parent already owned the child object.
After the linking operation, Gamgi always puts on top
the window and layer containing the linked objects.