Each field on a screen has a set of attributes that are fixed when you define the screen in the Screen Painter. When an ABAP program is running, a subset of the attributes of each screen field can be addressed using the system table SCREEN.

SCREEN is like an internal table with a header line. However, you do not have to declare it in your program. You cannot display it in the Debugger, and cannot use any work area other than its header line to address it. It has the following structure:

The final column contains the corresponding attributes of the screen fields in the Screen Painter.

You can modify SCREEN in your ABAP program during the PBO event of a screen. Its contents override the static attributes of the screen fields for a single screen call. The only statements that you can use with SCREEN are:

You cannot use any further additions in the LOOP AT SCREEN statement.

The component NAME contains the name of the screen field. The components GROUP1 to GROUP4 can contain any three-character code. These codes allow you to include screen fields in up to four modification groups. The screen field can belong to different modification groups. Modification groups are like an extra key field for the table SCREEN that allow you to change the attributes of all of the elements in a group simultaneously. You assign elements to modification groups statically in the Screen Painter, although you can overwrite them dynamically in a program.

The remaining components are for reading and activating or deactivating the display attributes of screen fields. For all components other than LENGTH, 1 means active and 0 means inactive.

There are certain hierarchy rules between the components ACTIVE, INPUT, OUTPUT, and INVISIBLE. They also have different effects depending on their respective static settings.

The ACTIVE component has no equivalent in the element attributes. Instead, it changes the components INPUT, OUTPUT, and INVISIBLE.

At the beginning of the PBO, ACTIVE is always set to 1, regardless of the static attribute settings. Setting ACTIVE to 0 automatically sets INPUT = 0, OUTPUT = 0, and INVISIBLE = 1. Any other changes to the settings of INPUT; OUTPUT, and INVISIBLE for the same table line are ignored. Conversely, setting INPUT = 0, OUTPUT = 0, and INVISIBLE = 1 sets ACTIVE to 0, and any further assignment to ACTIVE for the same table line will also be ignored. The setting ACTIVE = 1 has no other effect on the attributes. The only purpose of the ACTIVE component is to allow you to make a screen field inactive through a single assignment. You should particularly note that a module call linked to a FIELD statement in the screen flow logic is always executed, even when SCREEN-ACTIVE = 0 for the field in question. If you want to prevent a module from being processed for an inactive field, you must specify the FIELD and MODULE statements separately.

There are eight possible combinations of ACTIVE, INPUT, OUTPUT, and INVISIBLE, that have the following effect on screen fields:

If a field is statically-defined as Output only, setting INPUT = 1 has no effect. INPUT is always 0 for these fields. Masking user input by asterisks can be used for entering user passwords.

If a whole line becomes invisible when you make fields invisible, the screen is automatically made smaller. You can, however, switch off this attribute in the static screen attributes by selecting Switch off runtime compression.

When you set REQUIRED = 1, a field that is ready for input is made mandatory. Users can only leave the screen when all mandatory fields contain an entry. Exception: Function codes with type E and modules with the AT EXIT-COMMAND addition.

When you set DISPLAY_3D = 0, the three-dimensional frame for input/output fields is removed. You cannot use DISPLAY_3D = 1 to create a three-dimensional effect for text fields or screen fields with the Output only attribute.

Setting VALUE_HELP to 0 or 1 switches the input help button off and on respectively.

If you set INTENSIFIED = 1, the field contents of input fields are changed from black to red. The contents of output fields are changed from black to blue.

You can set the LENGTH component to a value shorter than the statically-defined output length (vislength) for input/output fields and Output only fields. This allows you to shorten their output length. You cannot shorten other screen elements, or lengthen any screen elements.

This example shows a simple screen modification. Program DEMO_DYNPRO_MODIFY_SCREEN demonstrates all possible modifications.