
Screen Section Entry Skeleton
A Screen Description entry specifies the attributes, behavior, size
and location for a referenced screen item which is accepted or displayed at run
time.
The availability of screen attributes is dependent on your terminal
hardware and operating system and COBOL run-time support.
The following are
not a part of X/Open screen handling:
- ACCEPT (Formats 3 and 5)
- AUTO-SKIP (synonym for AUTO)
- BEEP (synonym for BELL)
- COL (synonym for COLUMN)
- CONTROL
- DISPLAY (Format 3)
- EMPTY-CHECK (synonym for REQUIRED)
- GRID
- LEFTLINE
- LENGTH-CHECK (synonym for FULL)
- NO-ECHO (synonym for SECURE)
- OCCURS
- OVERLINE
- PROMPT
- SIZE
- ZERO-FILL
General Format

Syntax Rules
- Each Screen Description entry must start with a level number from
01 through 49.
- Each level 01 item must have a screen-name.
- Screen-name must immediately follow level number and conform to
the rules for user-defined names.
- A screen item can be referenced only in a Format 4 ACCEPT or
Format 2 DISPLAY statement.
- Each elementary screen item must contain at least one of the
following clauses: BELL, BLANK LINE, BLANK SCREEN, COLUMN, LINE, PICTURE,
VALUE.
- The data items in the FROM, TO and USING phrases are associated
with the screen item. The USING phrase is equivalent to the combination of a
FROM and TO phrase, each specifying the same field.
-
An ACCEPT can be executed on a group screen item
containing screen items with FROM or VALUE phrases only if that group also
contains screen items with TO or USING phrases.
- The clauses following screen-name can be specified in any order.
- A clause that appears in the description of a group screen item
applies to all the elementary subordinate items in that group in whose
descriptions it would be allowed.
- Any non-01 level screen item can have a data name, FILLER, or no
name. If no name is used, then FILLER is assumed (and the item can never be
explicitly referenced).
- If the same clause is specified more than once for the same
screen item, the clause which appears at the lowest level within the hierarchy
is the one which takes effect.
-
Table 1 summarizes the screen
description entry clauses available in the Screen Section for use with
different types of screen fields
and the WITH phrase options for use
with the ACCEPT and DISPLAY statements.
Screen Description Entry Clauses/ WITH Phrases
|
Screen Section |
WITH
Phrase
|
Input Field |
Output Field |
Update Field |
Literal Field |
ACCEPT |
DISPLAY |
AUTO |
X |
|
X |
|
X |
|
BACKGROUND-COLOR |
X |
X |
X |
X |
X |
X |
BELL |
X |
X |
X |
X |
X |
X |
BLANK |
X |
X |
X |
X |
|
X |
BLANK WHEN ZERO |
X |
X |
X |
|
|
|
BLINK |
X |
X |
X |
X |
X |
X |
COLUMN |
X |
X |
X |
X |
|
|
ERASE |
X |
X |
X |
X |
X |
|
FOREGROUND-COLOR |
X |
X |
X |
X |
X |
X |
FULL |
X |
|
X |
|
X |
|
GRID |
X |
X |
X |
X |
X |
X |
HIGHLIGHT |
X |
X |
X |
X |
X |
X |
JUSTIFIED |
X |
X |
X |
|
|
|
LEFT-JUSTIFY |
|
|
|
|
X |
|
LEFTLINE |
X |
X |
X |
X |
X |
X |
LINE |
X |
X |
X |
X |
|
|
LOWLIGHT |
X |
X |
X |
X |
X |
X |
OCCURS |
X |
X |
X |
|
|
|
OVERLINE |
X |
X |
X |
X |
X |
X |
PROMPT |
X |
|
X |
|
X |
|
REQUIRED |
X |
|
X |
|
X |
|
REVERSE-VIDEO |
X |
X |
X |
X |
X |
X |
RIGHT-JUSTIFY |
|
|
|
|
X |
|
SECURE |
X |
|
X |
|
X |
|
SIGN |
X |
X |
X |
|
|
|
SIZE |
X |
X |
X |
X |
X |
X |
SPACE-FILL |
|
|
|
|
X |
|
TRAILING-SIGN |
|
|
|
|
X |
|
UNDERLINE |
X |
X |
X |
X |
X |
X |
UPDATE |
|
|
|
|
X |
|
Table 1: Permitted Use of
Options
Key:
X |
Clause or option allowed |
Input field |
Screen item whose description contains a TO
phrase |
Output field |
Screen item whose description contains a FROM
phrase |
Update field |
Screen item whose description contains a USING
phrase |
Literal field |
Elementary screen item whose description
contains no PICTURE clause. |
General Rules
- Screen-name assigns a name to the screen item described in the
screen description.
- Screen descriptions define areas on the screen. Each entry
consists of a level number, an optional screen-name, and various optional
clauses relating to the positioning of fields as well as to console functions.
- When the screen item is displayed, data is taken from the literal
or data item named in the associated FROM or USING phrase. Items with the TO
phrase only are treated as though FROM SPACE or FROM ZERO were specified,
depending on the type of screen item.
- When the screen item is accepted, the data entered is moved from
the screen to the data item named in the TO or USING phrase. Depending on the
category of the item, conversion and de-editing are done if necessary.
- An input field is a screen item whose description contains a TO
phrase.
- An output field is a screen item whose description contains a
FROM phrase.
- An update field is a screen item whose description contains a
USING phrase.
- A literal field is an elementary screen item whose description
contains no PICTURE clause.
- An ACCEPT of a group screen item consists of accepting those
elementary subordinate items that are input or update fields. They are accepted
in the order their descriptions appear in the Screen Section at the screen
positions indicated by the screen descriptions. Unless otherwise specified in
the CURSOR IS clause (see the topic
The Special-Names
Paragraph in the chapter Environment
Division), the cursor is initially positioned at the start of the first
item. As the ACCEPT operation into each item is terminated, the cursor moves to
the start of the next item.
- A DISPLAY of a group screen item consists of displaying those
elementary subordinate items that are output, update or literal fields. They
are displayed simultaneously at the screen positions indicated by the screen
descriptions.
- If the length of an ACCEPT or DISPLAY screen item exceeds the
length of the current line, wraparound is to the next line.
- If a screen item is too large to fit within the physical screen,
truncation occurs at the first character that is off-screen for output fields
and alphanumeric input and update fields, and at the first field that is
off-screen for numeric and numeric edited input and update fields.