| Windows and forms in programs / OPEN WINDOW | |
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 according to its contents.
When using the TUI mode, the AT line, column clause defines the position of the top-left corner of the window on the terminal screen and 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. In addition to the lines needed for a form, allow room for the COMMENT line, the MENU line, the MENU comment line and the ERROR line. 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.