HP Data Entry and Forms Management System (VPLUS) Reference Manual (32209-90024)

654 AppendixL
A Programmer’s Guide to VPLUS
VPLUS Intrinsic Calls
For terminals that have local form storage, the current form may
optionally be loaded into local form storage if it is not already present.
Bit 8=0 Do not enable A/M/U (default).
Bit 8=1 Enables A/M/U.
If bit 8 is set to 1, users may access the A/M/U. Currently on VPLUS
version B.04.20, a VENVCNTL.PUB.SYS file can also control this option; the
format of this file is discussed in the Communicator, Volume 2, Issue 13
(UB-DELTA-1).
Bit 0=0 Do not enable the touch screen feature (default).
Bit 0=1 Enable the touch screen feature.
As of VPLUS version B.04.10, VREADFIELDS can be used to read a field
number that has been “touched”. Terminals that support the touch screen
feature are listed in the VPLUS/V Reference Manual Appendix G.
Reading Data from the Screen
After displaying the screen along with any initial values, the user is ready to input data.
VREADFIELDS triggers a read from the user. The read is satisfied when the user presses E
or one of the function keys. Also if the HPTOUCH feature is implemented, the read is
satisfied when a user selects a field on the form. For more information on the HPTOUCH
feature, refer to the VPLUS/V Reference Manual. The VPLUS Enhancement section
briefly discusses this feature.
VREADFIELDS
Purpose: to trigger a read from the user.
VREADFIELDS allows users to enter data. The read is satisfied if the user presses E or any
other function key. If E is pressed, data is transferred from the screen to the data buffer in
the comarea extension. Data is read in screen order, from top to bottom, and left to right.
If a function key is pressed, control is returned to the program without any data being
transferred to the VPLUS data buffer in the comarea extension. Instead, the LASTKEY
word in the comarea array is set. LASTKEY contains a value corresponding to the function
key that satisfied the read trigger. LASTKEY will take on a value as follows:
0 Enter Key
1 - 8 Corresponding to F1-F8
If the HPTOUCH feature is implemented, VREADFIELDS is satisfied when a user selects a
field. IN this case, no data is transferred to VPLUS’s data buffer. Instead, the LASTKEY
word in the comarea array is set to a negative number which indicates the field number
selected. The number is negative to distinguish it from the function key’s numbers which
are positive 1 through 8.
The only parameter passed to VREADFIELDS is COMAREA. Within the COMAREA, the
TERMOPTIONS word can be set to perform some advanced functions. These include setting
up automatic reads or having a timed read.
AUTOREAD is used when VREADFIELDS is terminated by a function key instead of E. For