Flags specifying various characteristics of the fields.
public enum Flag
If e_comb is set, the field is automatically divided into as many equally spaced positions, or combs, as the value of MaxLen, and the text is laid out into those combs. Meaningful only if the MaxLen entry is present in the text field and if the Multiline, Password, and FileSelect flags are clear.
If e_combo is set, the field is a combo box; if clear, the field is a list box.
If e_commit_on_sel_change is set, the new value is committed as soon as a selection is made with the pointing device. This option enables applications to perform an action once a selection is made, without requiring the user to exit the field. If clear, the new value is not committed until the user exits the field.
If e_edit is set, the combo box includes an editable text box as well as a dropdown list; if clear, it includes only a drop-down list. This flag is meaningful only if the e_combo flag is set.
If e_file_select is set, the text entered in the field represents the pathname of a file whose contents are to be submitted as the value of the field.
If e_multiline is set, the field can contain multiple lines of text; if clear, the field's text is restricted to a single line.
If e_multiselect is set, more than one of the field's option items may be selected simultaneously; if clear, no more than one item at a time may be selected.
If e_no_export flag is set, the field must not be exported by a submit-form action.
If e_no_scroll is set, the field does not scroll (horizontally for single-line fields, vertically for multiple-line fields) to accommodate more text than fits within its annotation rectangle. Once the field is full, no further text is accepted.
If e_no_spellcheck is set, text entered in the field is not spell-checked.
If e_password If set, the field is intended for entering a secure password that should not be echoed visibly to the screen. Characters typed from the keyboard should instead be echoed in some unreadable form, such as asterisks or bullet characters. The value is not stored if this flag is set.
Push Buttons flags
Radio buttons flags
If e_radios_in_unison is set, a group of radio buttons within a radio button field that use the same value for the on state will turn on and off in unison; that is if one is checked, they are all checked. If clear, the buttons are mutually exclusive (the same behavior as HTML radio buttons).
If e_read_only flag is set the user may not change the value of the field. Any associated widget annotations will not interact with the user; that is, they will not respond to mouse clicks or change their appearance in response to mouse motions. This flag is useful for fields whose values are computed or imported from a database.
If e_required flag is set, the field must have a value at the time it is exported by a submit-form action.
If e_rich_text is set, the value of this field should be represented as a rich text string. If the field has a value, the RV entry of the field dictionary specifies the rich text string.
If e_sort is set, the field's option items should be sorted alphabetically. This flag is intended for use by form authoring tools, not by PDF viewer applications. Viewers should simply display the options in the order in which they occur in the Opt array.
If e_toggle_to_off is clear, exactly one radio button must be selected at all times; clicking the currently selected button has no effect. If set, clicking the selected button deselects it, leaving no button selected.