OPEN WINDOW

Syntax

OPEN WINDOW identifier
   [ AT line, column ]
   WITH { FORM form-file
        | height ROWS, width COLUMNS
        }
   [ ATTRIBUTES ( window-attribute [,...] ) ]

{ BLACK | BLUE | CYAN | GREEN
| MAGENTA | RED | WHITE | YELLOW
| BOLD | DIM | INVISIBLE | NORMAL
| REVERSE | BLINK | UNDERLINE
| BORDER
| TEXT = "string"
| STYLE = "string"
| PROMPT LINE integer
| MENU LINE integer
| MESSAGE LINE integer
| ERROR LINE integer
| COMMENT LINE { OFF | integer }
}

1. identifier is the name of the window. It is always converted to lowercase by the compiler.
2. line is the integer defining the top position of the window. The first line in the screen is 1, while the relative line number inside the window is zero.
3. column is the integer defining the position of the left margin. The first column in the screen is 1, while the relative column number inside the window is zero.
4. form-file defines the name of the compiled form file, without .42f extension.
5. height defines the number of lines of the window in character units; includes the borders in character mode.
6. width defines the number of lines of the window in character units; includes the borders in character mode.

Usage

An OPEN WINDOW statement can have the following effects:

• Declares a name (the identifier) for the window.
• Indicates which form has to be used in that window.
• Specifies the display attributes of the window.
• When using character mode, specifies the position and dimensions of the window, in character units.

For graphical applications, use this instruction without the AT clause, and with the WITH FORM clause.

The window identifier must follow the rules for identifiers and be unique among all windows defined in the program. Its scope is the entire program. You can use this identifier to reference the same Window in other modules with other statements (for example, CURRENT WINDOW and CLOSE WINDOW).

The compiler converts the window identifier to lowercase for internal storage. When using functions or methods receiving the window identifier as a string parameter, the window name is case sensitive. We recommend that you always specify the window identifier in lowercase letters.

The runtime system maintains a stack of all open windows. If you execute OPEN WINDOW to open a new window, it is added to the window stack and becomes the current window. Other statements that can modify the window stack are CURRENT WINDOW and CLOSE WINDOW.