@@27 List box definition

This function is used to redefine a field as a list box. A list box can contain colored text and bar graphs. Refer to the following for further details.

In all installed panels the field text LBOX are used as a link between the @@ function and the field.

Disable action is executed when nothing is selected in the list box. This function is used to disable, for example, the Open and Delete buttons in the example given below.

Double clicking in the list box will initiate a Special action.

If no selection is made, the color code for the list box is the same as the one for the background default screen.



Field ID

The field ID is the direct address to data. The field ID consists of a starting control character followed by a reference number and ends with the ending control character ampersand (&) or a new starting control character.
Note: All control characters are replaced by a space when you display the panel on-screen or print it out.

Field text

For the most part, the field text definition is used for the following @@ functions to establish a connection between the function and the field: @@24 Button definition, @@27 Listbox definition and @@29 Static control definition.

Use the starting control characters together with the field text.
Note: If the field text in the @@ function and the related field does not correspond, the field is an entry field.

Field number

The field number defines the position of the field in the panel. You can find the field number by counting from the left to the right and from top to bottom.

You can use the field number to connect a @@ function with a field.
Note: If the field number in the @@ function and the related field do not correspond, the field is as entry field.
Use the starting control characters together with the field number.
Every time a new field is inserted or removed, you must recheck field positions. Therefore, you must use the field reference number or field text functions instead.

Control attributes

Control character Description Example
H Horizontal scrollbar @@27;LBOX;HTE;?2002;;;10;1000;0;;D4;D6;F2;
N No selection @@27;LBOX;G1TN;?0;;;11;1000;0;;F99;
M Multiple selection @@27;LBOX;G1MT;?0;;;11;1000;0;;F2;
E Extended selection @@27;LBOX;HTE;?2002;;;10;1000;0;;D4;D6;F2;
T Table header visible @@27;LBOX;HTE;?2002;;;10;1000;0;;D4;D6;F2;
G (default) Owner drawn text list box @@27;LBOX;GHTE;?2002;;;10;1000;0;;D4;D6;F2
G0 Standard list box @@27;LBOX;G0HTE;?2002;;;10;1000;0;;D4;D6;F2;
G1 Owner drawn text and bar graphic list box @@27;LBOX;G1T;?0;;;11;1000;0;;F2;

Help number

Syntax: ?x

The "x" is the help ID in the IPF file and is an integer from 1 to 65535. If ? 0 is given, then the help ID is calculated with respect to the field.

The help number is reserved in this way:

Value Reserved
1 <= x = 999 Panel help
1000 = x = 9999 Component help
10000 = x = 19999 Field help (2 byte integer)
20000 = x = 29999 Field help (4 byte integer, real, date and time)
30000 = x = 39999 Field help (Characters)
30001 = x = 65535 General help

Relative character position

This function defines a relative character position as it relates to a current character position. If no value is given, the character position is defined as the current character position.

Relative line position

This function defines the relative line position as it relates to the current line position. If no value is given the position is defined as the current line position.

Visible lines

This value defines the height measured in number of lines in the panel.

Maximum number of lines

This value defines the maximum number of lines allowed. This value is most often set to 1000 lines.

Visible characters

Integer > 0 and < 132. This defines the number of visible characters. If no value is given, then the length of the field defines the number of visible characters.

Color code

Color includes both the foreground and the background color. The color code is calculated by the using this formula:

Note: The default color can not be changed when using the @@29 - @@32 functions


The number (7) represents a pale gray background with black text.

The number (0313) represents a dark cyan background with yellow text.

Color code table

Code Color Code Color
00 Black 10 Dark red
01 Red 11 Dark pink
02 Dark green 12 Green
03 Yellow 13 Dark cyan
04 Blue 14 Brown
05 Pink 15 White
06 Cyan 16 Light green
07 Pale gray 17 Pale green
08 Dark gray 18 Default list box yellow
09 Dark blue 19 Light yellow

Value field

Shows the values/columns in the list box where the calculations is performed.

Disable section

Syntax: Dx, D+x, D-x

For Dx, "x" is a positive number interpreted as the absolute field number.

For D+x or D-x, "x" is a positive number interpreted as the relative field number to the current field.

Special action

  • RETURN VALUE action


    This action returns values to the field described by the field reference The control character in the field reference gives the field type.

  • REXX call action

    Syntax: Cx

    "x" is the REXX command number with a range from 1 to 99.

    In the start-up CMD file, you can specify environment variables to define the REXX command file attached to the REXX command number, such as SET REXXC1 = C:\REXX\BACKUP.CMD. If no environment variables are defined, then the default REXX command file names are REXXC1.CMD, REXXC2.CMD, and REXXC99.CMD.

  • FUNCTION KEY action

    Syntax: Fx

    where "x" is defined as the function key number to be simulated. It can contain be one or more digits The action simulates the use of the key and is performed immediately such that the rest of the special function definition is skipped. F0 is treated as if the Enter (Return) key was pressed and F3 is treated as the Escape (Esc) key.

  • PANEL action

    Syntax: Sx

    "x" is a positive number, interpreted here as a panel number. Without returning to the calling program, the panel system handles the panel that is specified in the action as if a call was made to display the panel. You can divide one panel into other panels without changing the calling program.
    Note: The data arrays are the same for the whole series of panels.


    The window is terminated.

  • DELAY action

    Syntax: Wx

    Where "x" is a positive number interpreted as a delay in seconds.

    The panel system waits the specified number of seconds before resuming.