Defining a New Window

A window is a physical area of the display screen that you can use to type into and/or display a particular stream.

You can define a window by giving it all of the desired attributes at once using the DEFINE.WINDOW command, or you can issue that command followed by one or more CHANGE.WINDOW commands to build the attributes for the window. The attributes for the window remain in effect until modified via the CHANGE.WINDOW command.

Following are the attributes you need to know to define a window. The operand for specifying each attribute is enclosed in parentheses.
  • The name of the window (window-name).
  • The location of the window on the display screen (row, column, lines, and width).

    Row refers to the number of the top line in the window. Column specifies which column of the screen the left side of the window is to occupy. Lines specify the number of lines in the window. Width specifies the number of character positions in each line. If you specify a negative value for either row or column, the Session Manager interprets the value as relative to the bottom or right side of the screen, respectively.

    You can use the word MAX for either the line or width operand instead of specifying a number. If you specify MAX for the line operand, the window contains the remaining lines on the screen or until a line is encountered that has been defined for another window. If you specify MAX for the width operand, the window's width is determined by the number of character positions in the first line of the window.

    In the example below, the TEST window was defined first beginning in row 22, column 1 and the SAMPLE window begins in row 1, column -20. If you define a new window beginning in row 1, width MAX, and lines MAX, the window covers rows 1 through 21 and columns 1-59.

    Note: The screen in the example has a column width of 80.

    You can also specify WRAP for the width value instead of MAX or a number. In this case, the width of the window starts from the column value specified on the command and continues to either the beginning of the next window or to the last row and column on the screen. The WRAP operand can only be used when the value for lines is 1.

    Note: The first character position in a window is used as a terminal attribute byte and is protected. Therefore, a window defined with a width of 1 is useless.
  • Whether you want the terminal's audible alarm to sound when the window scrolls to display new information in the stream (ALARM).
  • How long you want a window to be held in place before Session Manager scrolls it (HOLD). The window can remain at one position a specified number of seconds or until you press the Enter or any program function (PF) key. While the window is held in place, the keyboard is locked.
  • How many lines are to be repeated in the window when it scrolls over the stream (OVERLAP). For example, if you specify OVERLAP(2) in defining a window, the bottom or top 2 lines in the window are repeated when you move the window forward or backward, respectively.

    If you move the above window forward a complete page, lines 4 and 5 are repeated.

  • Whether you can enter data in the window (PROTECT).
  • The name of the stream that is to receive the information typed in the window and the intensity at which the information is to be displayed (TARGET).
  • How much information is to enter the specified stream before the window scrolls to display it (UPDATE). When a window is displaying the bottom of a stream, it waits for new information to enter the stream before it moves. With the UPDATE operand, you can specify whether the window is to display every line of information as it enters the stream, every page of information, or just the newest information. In the latter case, some lines of information might be skipped over because the window scrolls directly to the bottom of the stream.
  • The name of the stream the window is to display (VIEW).

For more information on the above operands, see the syntax description for the DEFINE.WINDOW command in z/OS TSO/E Command Reference.

When you define a window on the display screen, the physical location of the window cannot exceed the physical limits of the display screen unless you define the window as one line that wraps the screen. In addition, a new window cannot overlap the physical location of an existing window.