Defining the tabbing order

Control the order of tabbing through the fields with the TABINDEX attribute.

When a dialog is executing, the end-user can jump from field to field with the keyboard by using the Tab and Shift-Tab keys. One can tab out of an INPUT ARRAY sub-dialog with Ctrl-Tab and Shift-Ctrl-Tab accelerators (in INPUT ARRAY, Tab and Shift-Tab loop in the fields of the current row).

Consider using the OPTIONS INPUT WRAP instruction to force the focus to stay in the dialog, when tabbing out of the last form element controlled by the dialog.

The order in which the fields can be visited with the Tab key can be controlled with a program option and the TABINDEX form field attribute.

The FIELD ORDER dialog attribute defines the way tabbing order works (it can also be defined globally with OPTIONS FIELD ORDER mode). Tabbing order can be based on the dialog binding list (FIELD ORDER CONSTRAINED, the default) or it can be based on the form tabbing order (FIELD ORDER FORM). It is recommended that you use the FIELD ORDER FORM option, to use the tabbing order specified in the form file.

The TABINDEX field attribute allows tabbing order in the form to be defined for each form item. By default, the form compiler assigns a tabbing index for each form item based on the position of the item in the layout.

Important:

TABINDEX values must be unique in a form.

Form elements that can get the focus are:

Simple form fields controlled by INPUT or CONSTRUCT,
Read-only lists or treeviews controlled by DISPLAY ARRAY,
Editable list cells controlled by INPUT ARRAY,
Simple buttons controlled by a COMMAND interaction block.

If you use the keyboard to tab into a form element, the focus will go to the next (or previous) element that is visible and activated. In other words, if a form item is hidden or disabled, it is removed from the tabbing list.

The tabbing position of a read-only list driven by a DISPLAY ARRAY binding is defined by the TABINDEX of the first field.

When TABINDEX is set to zero, the form item is excluded from the tabbing list. However, the item with TABINDEX=0 can still get the focus with the mouse (or when you tap on it on a mobile device).

The NEXT FIELD instruction can also use the tabbing order, when executing NEXT FIELD NEXT and NEXT FIELD PREVIOUS.

When moving columns around in a TABLE or TREE container, new tab indexes are assigned to columns, so that input tabbing order corresponds to the visual column order. If the order of the columns in an editable list shouldn't be changed, freeze the table columns with the UNMOVABLECOLUMNS attribute of the TABLE/TREE.