How to make HP48G inputforms in System-RPL

                  by Sune Bredahl, ec947086@ebar.dtu.dk


If you're familiar with programming in system-RPL, then here's some info
on making *fast* dialog-boxes (input forms) on the '48G.

This includes _all_ types of standard fields:

(DF)    Data fields:            ( normal INFORM-style input fields )
(EDF)   Extended data fields:   ( allows you to select from var. browser )
(LF)    List fields:            ( have pre-determined set of values )
(CF)    Check fields:           ( checkmark-style fields )

The following is completely undocumented so don't blame me if anything screws
up.

            *****************************************************



The internal INFORM command has the address #199EB (!) and accepts input
arranged the following way;


* LABEL DEFINITIONS

"label"               ( label string for field )
#x_offset             ( display x-coordinate )
#y_offset             ( display y-coordinate )

( more label definitions follow... )

* FIELD DEFINITIONS

' DROPFALSE            ( each field starts with DROPFALSE )
#x_offset              ( display x-coordinate )
#y_offset              ( usually label#y_offset + #2 )
#lenght                ( length of field )
#height                ( usually NINE )
#menutype              ( DF:ONE, EDF:TWENTYTHREE LF:TWELVE CF:THIRTYTWO )
{ #type1 #type2 ... }  ( valid USER-types, LF/CF:MINUSONE )
#fieldstyle?           ( FOUR:DF/EDF, SEVENTEEN:LF, MINUSONE:CF )
"helpInfo"             ( help string )
"vartxt" or { list }   ( EDF:"vartxt" LF:{ { "Hi" foo } etc. }, DF/CF:MINUSONE )
#?                     ( LF:SEVENTEEN, CF/DF/EDF:MINUSONE )
resetvalue             ( DF/EDF:any/MINUSONE, LF:{ "Hi" foo }, CF:TRUE/FALSE )
initvalue              ( same as above )

( more field definitions follow... )

* GENERAL INFO

#labels                         ( number of labels )
#fields                         ( number of fields )
' DROPFALSE
"TitleString"                  ( Title-string )


Note that #labels and #fields can be different. If you want some text anywhere
in the dialog box, then just enter it/them as the first label definition(s)
and change #labels accordingly. All text-strings can be replaced with msg.
numbers if you want to re-use some of the built-in stuff.


Stack output is this:

N+1:  field1
  N:  field2
  ...
  2:  fieldN
  1:  TRUE/FALSE     ; FALSE if [CANCEL] was pressed else TRUE


For each field type the output is;

DF/EDF:  any ( MINUSONE if empty/NOVAL )
CF:      TRUE/FALSE
LF:      { "Label" foo }

Note that the List Field returns the entire input-list and not only <foo>.
However, if <foo> is the program DROP <bar>, then one can simply COMPEVAL
the list to execute <bar>. This approach is useful if using the field to
control some system settings (see example below).

' DROPFALSE can be executed via #3A9B8 so a few bytes can be saved.


Here's an example;

ASSEMBLE

* unsupported entry points

HALTOK?        EQU #1446F
HALTERR        EQU #10FC6
sysINFORM      EQU #199EB
'DROPFALSE     EQU #3A9B8

                    NIBASC /HPHP48-K/
RPL
::

CK0NOLASTWD             ( no args req'd )

* always check if HALT is allowed

HALTOK?
NOTcase
HALTERR

* definitions of labels

"Some text" ONE TWELVE
"CHECK" FIFTYTWO TWELVE
"Normal" ONE TWENTYONE
"List field" ONE THIRTY
"Press CHOOSE" EIGHTY THIRTY

* definitions of fields

'DROPFALSE
FORTYFIVE                        ( x - offset )
TEN                              ( y - offset )
SIX                              ( checkmark uses six pixels )
NINE                             ( standard height )
THIRTYTWO                        ( CF menu )
MINUSONE                         ( not used by this field )
DUP                              ( neither is this )
"Also use [+/-] to check this"   ( help text )
MINUSONE                         ( not used by this field )
DUP                              ( ditto )
TRUE                             ( checkmark ON is reset value )
DUP                              ( and init value too )

'DROPFALSE
THIRTY                          ( x - offset )
NINETEEN                        ( y - offset )
FIFTY                           ( lenght of field )
NINE                            ( normal height )
ONE                             ( DF menu )
{ ZERO ONE }                    ( real and complex nums are valid )
FOUR                            ( DF field )
"Enter real or cmplx num."      ( help text )
MINUSONE                        ( not used by this field )
DUP                             ( ditto )
% 0.0001                        ( reset value )
MINUSONE                        ( no initial value / NOVAL )

'DROPFALSE
FIFTY                           ( x - offset )
TWENTYEIGHT                     ( y - offset )
TWENTYSEVEN                     ( lenght of field )
NINE                            ( height )
TWELVE                          ( LF menu )
MINUSONE                        ( not used by this field )
SEVENTEEN                       ( LF field )
"Also use [+/-] to select"      ( help text )
{ { "RAD" DROP SETRAD }         ( Field contents )
  { "DEG" DROP SETDEG }         ( First text-string is shown ... )
  { "GRAD" DROP SETGRAD } }     ( and selected 'list' will be popped on stack )
SEVENTEEN                       ( dunno )
{ "RAD" DROP SETRAD }           ( reset value )
DUP                             ( and init value too )

'DROPFALSE
EIGHTY                          ( x - offset )
THIRTYSEVEN                     ( y - offset )
FIFTEEN                         ( lenght of field )
NINE                            ( height )
TWENTYTHREE                     ( EDF menu )
{ ZERO }                        ( not used by this field )
FOUR                            ( EDF field )
NULL$                           ( no help info )
"Reals in"                      ( Choose-menu string )
MINUSONE                        ( not used by this field )
%2                              ( reset value )
DUP                             ( and init value too )

* general info

FIVE                            ( four labels )
FOUR                            ( three fields )
'DROPFALSE
"(C) SUNE BREDAHL '94"          ( title string )

* now we're ready

sysINFORM
NOT                             ( if cancel was pressed )
?SEMI                           ( then exit program )
4UNROLL
COMPEVAL                        ( execute list with angle prog )
DUP
MINUSONE                        ( check for empty field )
EQUAL
IT
:: DROP "No number entered !" ;
SWAP
ITE
"Checkmark OK !"
"NO Checkmark !"
SWAPROT
;

You don't have to compile this to see the result - just run EXAMPLE
(distributed with this doc).

Enjoy

Sune Bredahl