Common Properties


Scroll bars do not have titles.


A scroll bar has an integer value, which represents the slider's position in the control. The range of values is set by the properties MIN-VAL, MAX-VAL, and PAGE-SIZE. Setting the value outside of the legal range has an undefined effect.


SIZE and LINES describe the area of the scroll bar in window cells. If SIZE is omitted, the width of a vertical scroll bar is the standard width of the host system's scroll bar. A horizontal scroll bar extends to the right edge of the window when the scroll bar is created. If LINES is omitted, the system makes corresponding calculations — a horizontal scroll bar is standard height, and a vertical scroll bar extends to the bottom edge.


Scroll bars always use the system's colors.


EVENT-LIST is an exclusive list of events that are either sent to or withheld (blocked) from the program depending on the value of EXCLUDE-EVENT-LIST. See Common Screen Options for more information.


HORIZONTAL This style creates a horizontal scroll bar. Without this style, the scroll bar is vertical.
TRACK-THUMB This style causes the scroll bar to generate MSG-SB-THUMBTRACK messages while the slider is moved by the user. Without this style, the messages are suppressed. Use this style if you want to update the screen while the user is moving the slider (as opposed to immediately after a new slider position is selected).

To minimize network traffic and optimize performance, MSG-SB-THUMBTRACK events are generated differently for thin client applications. With thin client applications, when the slider is moved by the user, a single MSG-SB-THUMBTRACK message is sent immediately before the MSG-SB-THUMB message, and the scroll bar is automatically updated.