Browse Prior Art Database

Host Based Character Application Access to Scroll Bar Entry Fields

IP.com Disclosure Number: IPCOM000107519D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 3 page(s) / 148K

Publishing Venue

IBM

Related People

Aaker, KD: AUTHOR [+4]

Abstract

This article describes how an outbound display data stream can define a scroll bar field, a work station controller, or programmable work station using the best presentation available on the target display. Inbound data can be returned from the scroll bar field which can define a user-requested scrolling increment. This article also describes how a character-based display can be enhanced to provide graphical user interface (GUI)-like scroll bars, window borders, and selection choice indicators.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 43% of the total text.

Host Based Character Application Access to Scroll Bar Entry Fields

       This article describes how an outbound display data
stream can define a scroll bar field, a work station controller, or
programmable work station using the best presentation available on
the target display.  Inbound data can be returned from the scroll bar
field which can define a user-requested scrolling increment.  This
article also describes how a character-based display can be enhanced
to provide graphical user interface (GUI)-like scroll bars, window
borders, and selection choice indicators.

      A work station controller (WSC) provides attachment of multiple
non-programmable terminals (NPTs) to a host computer system.  The
host transmits an outbound display data stream to the WSC for
processing in order to create a display panel on an NPT.  A
programmable work station (PWS) terminal emulator is a product which
runs on the PWS giving the PWS user access to host-based NPT
applications; the PWS performs the function of a combined WSC and
NPT.  Most PWSs are all-points-addressable (APA), which enables GUI
presentation of scroll bars.

      The output display data stream can be enhanced to define a
scroll bar field.  The data stream describes the following about a
scroll bar field:
o    Location of the scroll bar
o    Orientation: vertical or horizontal
o    Size of the scroll bar on the display screen (number of rows or
columns)
o    Total rows or columns of scrollable data available to the host
o    Number of rows or columns of scrollable data available to the
host which are above or to the left of the first row or column
written on the display screen (scrollable panel area)

      The WSC (or PWS) uses the size of the scroll bar, total number
of rows/columns, and rows/columns above or left of what is on the
screen to determine the location and size of the "thumb" in the
scroll bar shaft.  A PWS can present a GUI scroll bar (very accurate
granularity on thumb location and size).  If the target NPT has
GUI-like "characters" (described below), the WSC will present a
GUI-like scroll bar (good presentation and fair granularity on the
thumb location and size).  Otherwise, a WSC will use a character
version of a scroll bar (for example, made up of an "A" for the top
scroll bar character, a "V" for the bottom scroll bar character, a
":" for an empty shaft position, and "*" for a thumb shaft position).
These characters can be customized.

      PWSs generally have a pointing device and NPTs could possibly
have a pointing device.  When a user "clicks" above the thumb in the
scroll bar, the PWS can send a roll-up attention identifier (AID) to
the host and the host will most likely rewrite the scrollable data
(just data to the PWS) and redefine the values for the scroll bar
(for example, moving the thumb up).  Likewise, if a user "clicks"
below the thumb in the scroll bar, the PWS can send a roll-down AID
to the host.

     ...