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

Chapter 6 357
USING VPLUS INTRINSICS
INTRINSIC DESCRIPTIONS
Controlling the Keyboard
As soon as the form is displayed, VSHOWFORM normally enables the keyboard so the user can
enter data. The next call is usually to VREADFIELDS, which locks the keyboard after the
entered data is read. In case of consecutive calls to VSHOWFORM, the following
showcontrol
bit can be set:
bit 10 = 0 Enable the keyboard.
1 Do not enable the keyboard.
The scenario is as follows:
• the last VREADFIELDS call locked the keyboard,
• for each of a series of consecutive calls to VSHOWFORM; set bit 10 of
showcontrol to one so
the keyboard is not enabled,
• for the last of the consecutive calls to VSHOWFORM, set bit 10 to zero to enable the
keyboard.
This ensures that keystrokes do not change a form while it is being displayed. Consecutive
calls to VSHOWFORM could be used to display a form with no fields, append another form to
it, and display this second form without doing a read in between.
Controlling Preload of Forms
On terminals with local form storage, VSHOWFORM first determines if the current form is
already in the terminal. If the form is in local storage, it is displayed from local storage. If
the form is not in local storage, it is preloaded into the terminal from the form definition
area of memory depending on
showcontrol , which can be set as follows:
bit 9 = 0 Do not preload the form.
1 Preload the form.
If bit 9 is zero, the form is written directly from the form definition area of memory to the
terminal screen. If bit 9 is one, the form is preloaded into local storage and then displayed
from local storage. One or more forms could be purged from local storage if there is not
room for the form that is being loaded. Note that purging could occur even when
lookahead is set to one.
Controlling the Touch Feature
On terminals with the touch feature, touch can be enabled or disabled with showcontrol ,
which can be set as follows:
bit 0 = 0 Do not enable the touch feature.
1 Enable the touch feature.
Controlling the Bell
By default (
termoptions bit 15 is set to zero), VSHOWFORM sounds the bell if neither the
screen nor the window line have been redisplayed. The bell can be suppressed in all cases
by setting the
termoptions bit to one.