Any DCL component can have a number of attributes. An attribute is
a name-value pair. An attribute can either be custom or predefined.
Custom attributes are for usage in DCL applications by means of the
function get_attr.
Predefined attributes influence the behavior of the DCL component
they are specified in.
call to be made on activation of the
tile (makes sense for a child tile only? to be added to
documentation of each tile as a predefined attribute (of child
tile?) (only used in lisp, otherwise this is a custom
attribute?)
The specified value of this attribute
can be true or false. The default value is true. A value of true
will enable the control. A value of false will disable the tile.,
controls enabled/disabled mode. default enabled can be changed at
runtime mode_tile 0