HP 3000 Manuals HP 3000 Manuals
User Defined Function Keys
Deleted Statements
HP Business BASIC/XL does not support the EDIT KEY and LIST KEY commands.
Use the terminal function key editing features instead.
Number of Softkeys Available
In HP Business BASIC/XL, you can define up to a maximum of 8 softkeys;
BASIC/260 let you define 24. For increased compatibility, do not develop
new programs with multiple and different softkey levels.
Video Enhancements in User Defined Function Keys
HP Business BASIC/XL does not support video enhancements in softkey
labels. In BASIC/260, it is common to highlight selected softkeys with
video enhancements. For increased compatibility, do not use enhancements
in softkey labels, use special characters (like asterisks) instead.
Example:
Hit_1_off: ON KEY 1 GOTO Hit_1_on; LABEL="Hit me "
.
.
.
Hit_1_on: ON KEY 1 GOTO Hit_1_off; LABEL="Hit me*"
Label Text Length in User Defined Function Keys
HP 260 softkeys have room for eighteen characters (2*9) in each softkey
label, HP 3000 softkeys have only have room for 16 characters (2*8) in
each softkey. For increased compatibility, use sixteen characters or
less in softkeys. The key display algorithm automatically centers
softkey labels. However, centering can be different in HP Business
BASIC/XL because the labels are a different width.
Real Softkey Interrupts
HP 260 softkeys can interrupt programs at any point. or during every
idle INPUT statement; pressing a softkey can stop a program in the middle
of a processing sequence. The example below illustrates:
ON KEY#8:"abort" GOTO Exit
LOOP
do some print processing
END LOOP
Pressing softkey 8, labeled "abort", lets you stop the processing of this
program in the middle of printing a report.
The HP 3000 does not process softkeys as interrupts; it traps pressed
keys only when a program is in an input state. The only real interrupt
is CTRL Y. CTRL Y is the equivalent of HALT and can be acted on with the
ON HALT statement in HP Business BASIC/XL. Pressing softkey 8 in the HP
Business BASIC/XL program has no effect and the statement inside the loop
continues to execute.
For increased compatibility do not use dynamic softkeys; only use
softkeys with input statements or WAIT statements. The migration aid,
BBCT250.PUB.SYS, automatically changes the WAIT statement to the
following:
LOOP
ACCEPT
END LOOP
This has the same effect in HP Business BASIC/XL as in BASIC/260.
Either use ON HALT GOTO to branch to code that sets up softkeys when
program logic requires a dynamic softkey, like in the first example, or
change the logic of your program when you migrate to HP Business
BASIC/XL.
Cursor Movement and INPUT in User Defined Function Keys
On the HP 260, pressing a softkey does not move the cursor. On HP 3000
terminals, however, pressing a softkey normally causes a carriage return
(CR-LF) to echo. This affects applications that use RPOS and CPOS (XPOS
and YPOS on the HP 260) afterward.
HP Business BASIC/XL softkeys also terminate input, unlike BASIC/260
softkeys. The variable being input when the key is hit will not be
assigned a value.
See the Input and Output section in this chapter for more details.