4.15.8 Variable-Sized Fields

If you want a dynamically changing field with variable width, this is the feature you want to put to full use. This will allow the user to enter more data than the original size of the field and let the field grow. According to the field orientation it will scroll horizontally or vertically to incorporate the new data.

To make a field dynamically growable, the option O_STATIC should be turned off. This can be done with

(field-opts-off! field O_STATIC)

It is usually not advisable to allow a field to grow infinitely.. You can set a maximum limit to the growth of the field with set-max-field.

The field info for a dynamically growable field can be retrieved with the procedure dynamic-field-info.

Recall the library routine new-field; a new field created with height set to one will be defined to a one line field. A new field created with height greater than one will be defined to be a multi-line field.

A one line field with O_STATIC turned off (dynamically growable) will contain a single fixed row, but, the number of columns can increase if the user enters more data than the initial field will hole. The number of columns displayed will remain fixed and the additional data will scroll horizontally.

A multiline field with O_STATIC turned off (dynamically growable) will contain a fixed number of columns, but, the number of rows can increase if the user enters more data than the initial field will hold. The number of rows displayed will remain fixed and the additional data will scroll vertically.