isCOBOL Evolve : Language Reference : Data Division : Screen Description
Screen Description
A screen description entry specifies attributes, behavior, size, and location of a screen item so that it can be referenced by an ACCEPT screen or a DISPLAY screen Statement. The screen description entry allows data items to be associated with the screen item so that the contents of the data item are displayed within the screen item or the value keyed into a screen item by the operator is placed in the data item.
General Format
Level-Number { Screen-Name } [ AUTO clause            ]
             { FILLER      } [ Background Intensity   ]
                             [ Foreground Intensity   ]
                             [ {BELL}                 ]
                               {BEEP}
                             [ BLANK clause           ]
                             [ BLANK WHEN ZERO clause ] 
                             [ {BLINKING}             ]
                               {BLINK   }
                             [ COLOR clause           ]
                             [ COLUMN clause          ]
                             [ CONTROL clause         ]
                             [ LINE clause            ]
                             [ FROM clause            ]
                             [ {FULL        }         ]
                               {LENGTH-CHECK}
                             [ JUSTIFIED clause       ]
                             [ NO-ECHO clause         ]
                             [ OCCURS clause          ]
                             [ OUTPUT clause          ]
                             [ PICTURE clause         ]
                             [ PROMPT clause          ]
                             [ {REQUIRED   }          ]
                               {EMPTY-CHECK}
                             [ REVERSE clause         ]
                             [ SAME                   ]
                             [ SIGN clause            ]
                             [ SIZE clause            ]
                             [ TAB-GROUP clause       ]
                             [ TAB-GROUP-VALUE clause ]
                             [ TO clause              ]
                             [ UNDERLINED clause      ]
                             [ UPPER and LOWER clauses]
                             [ USING clause           ]
                             [ VALUE clause           ]
                             [ ZERO-FILL clause       ]
                             [ Embedded Procedures    ]
Syntax rules
1. Screen-Name is a User-defined word, as defined in the Definitions section in the Preface of this document.
General rules
1. Level-Number may be any number from 1 through 49.
2. Clauses may be specified in any order.
3. For an elementary screen item, the associated screen description entry shall include at least one of the following:
o a FROM, TO, USING or VALUE clause;
o a BLANK (or ERASE) clause;
o a BELL clause.
4. If the FULL clause is specified, the JUSTIFIED clause shall not be specified.
5. If the same clause, other than an OCCURS clause, is specified at more than one level in the hierarchy of a screen item, the clause that appears at the lowest level of the hierarchy is the one that takes effect.
6. If the HIGHLIGHT and LOWLIGHT clauses are both specified in the hierarchy of a screen item, the clause that appears at the lowest level of the hierarchy is the one that takes effect.
7. The PICTURE clause may be omitted when an alphanumeric, national or numeric literal is specified in the USING clause. A PICTURE clause is implied as follows:
a. if the literal is alphanumeric, 'PICTURE X(length)'
b. if the literal is national, 'PICTURE N(length)'
c. if the literal is numeric, 'PICTURE 9(length)'
8. If the AUTO and TAB clauses are both specified in the hierarchy of a screen item, the AUTO clause takes effect. If the AUTO clause is implied (see the '-va' compile-time option in “Compiler Options“ in the isCOBOL Evolve User's Guide) and the TAB clause is specified, the TAB clause takes effect.
9. BELL and BEEP are synonymous and are treated as a commentary.
10. BLINKING and BLINK are synonymous and are treated as a commentary.
11. FULL and LENGTH-CHECK are synonymous and are treated as a commentary.
12. REQUIRED and EMPTY-CHECK are synonymous and are treated as a commentary.
13. The SAME clause is treated as a commentary.