Position and size of a window

Defining the window position and size in TUI mode

A typical OPEN WINDOW instruction for TUI mode specifies the position on the screen:

OPEN WINDOW w1 AT 10,5 WITH FORM "custlist"

When using the TUI mode (or traditional GUI mode), the AT line, column clause defines the position of the top-left corner of the window on the terminal screen. The terminal character-cell coordinates start at line 1 and column 1, referencing the top-left corner of the terminal.

The WITH lines ROWS, characters COLUMNS clause specifies explicit vertical and horizontal dimensions for the window. The expression at the left of the ROWS keyword specifies the height of the window, in character unit lines. This must be an integer between 1 and max, where max is the maximum number of lines that the screen can display. The integer expression after the comma at the left of the COLUMNS keyword specifies the width of the window, in character unit columns. This must return a whole number between 1 and length, where length is the number of characters that your monitor can display on one line.

Reserved window lines in TUI mode

In addition to the lines needed for a form, consider allowing room for the COMMENT line, the MENU line, the MENU comment line, and the ERROR line for the TUI mode.

The runtime system issues a runtime error if the window does not include sufficient lines to display both the form and these additional reserved lines.

The minimum number of lines required to display a form in a window is the number of lines in the form, plus an additional line below the form for prompts, messages, and comments.

Window geometry in GUI mode

When using the full GUI mode (without the traditional mode), the AT line, column clause is optional and if used, the WITH lines ROWS, characters COLUMNS clause is ignored, because the size of the window is automatically calculated, and the position is controlled by the window manager.

The size of a regular window is defined by the window container, and the content of the current form adapts to the size of the container. When using a modal window, the size of the window is computed from its content. The size of a modal window that shows a form defining a TABLE, is computed from the size of the TABLE element (see Controlling table rendering for more details)