HP 3000 Manuals HP 3000 Manuals
HP ALLBASE/QUERY User Interface and Limits Enhancements
by Victor Veres, Australian Software Operation
This release of ALLBASE/QUERY (previously known as HP Visor) features a
redesigned user interface modeled after ALLBASE/4GL. This interface
provides a high level of user interaction, field-based editing, and full
use of terminal features. It also helps achieve a common "look and feel"
with ALLBASE/4GL, so the two products may be used together in
complimentary fashion when the need arises. The fundamental design
principle for the user interface is the WYSIWYG (What You See Is What You
Get) philosophy.
Another feature of this release is the ability to select up to ten tables
and 255 columns for reporting (up from the previous three tables and 20
column limits).
The main features of the ALLBASE/QUERY user interface on MPE XL can be
summarized as follows:
* The display always provides an accurate reflection of the actual
input (that is, a WYSIWYG interface).
* Field editing and terminal features, such as insert character and
delete character, are available.
* ALLBASE/QUERY can display messages, and accept user responses via a
message "window" at the bottom of the screen.
* Excessive system input and output load is avoided since the user
interface does not use character based I/O.
This article describes the techniques used to obtain the required user
interface functionality on MPE XL.
Field Mode Operation
To satisfy the user interface requirements, the MPE ALLBASE/QUERY product
uses a "field mode." In this mode, user input is transmitted on a
field-by-field basis when the field is "committed." A field commit is
generated by the user pressing RETURN (end of record), or by pressing TAB
(alternate end of record). This implies that all user input must be
terminated by one of the above two characters. In this sense, user input
includes cursor motion, backtab, and commands such as screen redraw
(CONTROL L) and screen printing (CONTROL P).
Since ALLBASE/QUERY does not operate in block mode, the ENTER key is not
supported. Instead, ALLBASE/QUERY uses a function key to allow the user
to terminate a screen.
Display Highlighting
ALLBASE/QUERY provides a mechanism to specify the display enhancements
(such as inverse video, flashing display, or underlining). Highlighting
and color attributes may be specified for screen elements such as input
fields, text literals, display fields, error, and messages. This
mechanism is utilized when ALLBASE/QUERY is started from within
ALLBASE/4GL to inherit the ALLBASE/4GL settings, which contributes to the
common look and feel.
Terminal Requirements
ALLBASE/QUERY requires at least the terminal functionality provided by
the HP 2622 terminal.
ALLBASE/QUERY uses terminal format mode to create "input" fields on the
screen. This ensures that the user can only enter or alter data in the
current input field.
Using protected fields enables the user to edit the data already in a
field. This approach avoids performance limitations due to excessive I/O
traffic associated with character mode, while still preserving the
WYSIWYG philosophy of ALLBASE/QUERY.
Supported Terminals
The current release of ALLBASE/QUERY supports the following terminals:
* HP 2622 to HP 2628
* HP 239x
* HP 700/9x
* HP 150
* HP Vectra PC (With terminal emulation software)
Terminal Communication System
ALLBASE/QUERY uses a terminal communication system that is similar to the
HP-UX terminfo system. This system uses a number of terminal capability
files to determine the available terminal functionality and to drive the
terminal. Terminal capability files for all supported terminal types are
supplied with ALLBASE/QUERY. These files are in the HP4TERM.SYS group.
ALLBASE/QUERY uses an MPE XL variable to identify the terminal. This
variable can be set by the command file used to start ALLBASE/QUERY, or
by a logon UDC.
The ALLBASE/QUERY terminal capability files support all the normal
display enhancements and features provided by HP terminals, including the
line-drawing character set, color, and touchscreen operation.