Magnum One/Magnum One (Mid-American Digital) (Disc Manufacturing).iso/d13/q_aparad.arc/TOOLKIT.QA

Text File | 1991-03-13 | 8.4 KB | 265 lines

              PARADOX COMMON QUESTIONS AND ANSWERS

DETOOL

   1.  Do you need to play TKMENU/SETUPDOWAIT for each image in a
       multi-table form?

       Yes  and No.  You do need to  play  SETUPDOWAIT  for  each
       image that will have user interaction under the control of
       DOWAIT(" ") and a DPA Set.  SETUPDOWAIT creates a  DPA Set
       for  a  given  image and form.  In multi-table forms, each
       embedded form is a separate image, as a far as Paradox and
       DOWAIT(" ") are concerned.


   2.  When moving from image to  image in a DOWAIT(" ") session,
       how is the DPA Set for a given image activated?

       First, it will be helpful to note that only  one  DPA  Set
       can  be  active  in memory at any one time.  There are two
       ways to activate a  particular  DPA Set.  One method is to
       arrive in a table image through natural movement.  Natural
       movement in  this context means movement via a key defined
       as  a  regular  key.    Simply calling DOWAIT(" ") with  a
       particular table image active would be natural movement to
       that table image.  The second way to activate a DPA Set is
       by calling  ARRIVETABLE()  within  your  own  code.   This
       should be done  when  the  key  pressed by the user is not
       "regular" but instead evokes  "special"  processing  via a
       special key procedure or other procedure  such  as arrival
       or  departure  procedures.   It is always safe to issue an
       ARRIVETABLE() call.


   3.  I played TKMENU/SETUPDOWAIT and thereby created a  DPA Set
       script.  Is  that  enough to cause my procedure assignment
       to be active when needed?

       No, the DPA Set  script  has within it code that defines a
       procedure assignment  set.  The proc is named according to
       a specific  convention  as  follows:    the  letters "TK",
       followed by  the  table's  name,  and  then  an underscore
       character "_", followed  finally  by the form number to be
       used.  When no form is used, the  underscore  character is
       followed by the word "None."  When either ARRIVETABLE() is
       called by you (the programmer) or regular  movement brings
       DOWAIT(" ") to a new  image,  DOWAIT("  ")  itself creates
       on-the-fly a call to  a  proc  named  TKTableName_#.  If a
       proc by the appropriate name is not in RAM (the script had
       been played so as to load the proc into RAM), or  the proc
       cannot be found within  the  AUTOLIB  path, a script error
       will occur declaring that the necessary TKTableName_# proc
       is not defined.













   4.  What are the common mistakes in  writing  an INITWAIT(...)
       call?

       More description can be found  in  the  script DOW8DEMO.SC
       found in your TOOLKIT directory.

       INITWAIT(...) takes three parameters.  The first parameter
       denotes the  total number of workspace images that will be
       present during the execution of DOWAIT(" ").  All embedded
       forms in a multi-table  form  count.   Any other workspace
       images count.  Table-Lookup  tables  do  not  count unless
       they are also on  the  workspace.   Tables within SETPOPUP
       (if used) do not count unless left on the workspace.

       The  second  INITWAIT(...)  parameter  denotes  the  image
       numbers of the specific images  to  have  user interaction
       performed on them under the control of DOWAIT("  ")  and a
       DPA  Set.    A  WAIT  command  could  conceivably  control
       processing  of  a  workspace  table  so  that  the  second
       INITWAIT(...) parameter  need  not  be  informed  of  that
       table's image number.

       NOTE:  Numbering  of  images within a multi-table form are
       determined by chronological placement on the form,  not as
       one might assume such as a clockwise, counterclockwise, or
       other schema.

       The  third  INITWAIT(...)  parameter  spells out the table
       names of DPA Set controlled images, and  should correspond
       in order with parameter number 2  (above).   Misspellings,
       spaces, or even the inclusion  of a path in this parameter
       will cause a script error when DOWAIT(" ") tries to invoke
       a DPA  Set.  The error message usually says "TKTableName_#
       is not defined" and the culprit may be  within  this third
       parameter of INITWAIT(...).


   5.  Why do I have to press  <F2>  twice to end my edit session
       when using DOWAIT(" ")?

       You don't!  Usually, <F2> is defined as an  EXIT  type  of
       key  within your DPA Set script.  If  this  is  the  case,
       pressing  <F2> will end, or EXIT  from,  the  DOWAIT("  ")
       session.    The  "DO_IT!"  process  is  not  automatically
       invoked.  Common processing would be as follows:

       ....
       Dowait(" ")               ;F2 here would have been an EXIT
                                         ;from dowait.
       If retval="F2" then
          DO_IT!
       Endif
       ....




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   6.  Are there any cautions in using DOWAIT(" ")?

       Only in  terms  of  your  computer's  memory  constraints.
       Generally, you should be cautious about using  DOWAIT(" ")
       if you have less than around 90K of MEMLEFT() once Paradox
       has  been  loaded.    Efficient  PAL  programming  is also
       important.


   7.  What causes the message "TKTableName_#" not defined?

       A procedure by the name of the current workspace image and
       form number is not in RAM memory, or is  not  found  along
       the AUTOLIB  path.  A misspelling, or other naming problem
       could   exist   within  the  third   parameter   of   your
       INITWAIT(...) call.


   8.  Why have I been getting the  run  error that a value xx is
       not in the range of yy to zz, etc.?

       Usually, this is caused  by  trying  to reference an array
       element that does not exist.  In the  context  of DOWAIT("
       "), this could be due to invoking the wrong DPA Set.   Or,
       you may have modified a form to be used within DOWAIT(" ")
       and  since  then  have  not  redone the DPA Set script  by
       replaying SETUPDOWAIT.


   9.  What is a DPA Set?

       DPA Set  stands for DOWAIT Procedure Assignment Set.  This
       is the set of Arrival, Departure, and  Special Procedures,
       and also the  key  definition  you  have  declared through
       playing TKMENU/SETUPDOWAIT.   This would be the equivalent
       of   Paradox   version  2.0's   TOOLKIT/Field_Define   and
       Key_Define scripts.


  10.  How do I keep my current  image  on the Canvas when I want
       to put up a message, or use an ACCEPT command?

       Issue  ECHO NORMAL    ECHO OFF  followed by your commands.
       ECHO NORMAL writes  the  current  workspace  image  to the
       Canvas.  ECHO OFF keeps the image on the Canvas so you may
       write  to  it.    A  new procedure within the version  3.0
       manual  is REFRESHCANVAS(), which performs similar a  duty
       for use with the Runtime.


  11.  TKACCEPT is  a  vital,  and  often  misunderstood  TOOLKIT
       variable.  How and when is it used?





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       TKACCEPT  is  a  logical variable set to  either  True  or
       False.  The value  of  TKACCEPT  determines whether or not
       the key pressed by  the  user  (stored  in TKCHAR) will be
       passed through to  Paradox.   For instance, a user presses
       the  right-arrow  key.    You  (the  PAL  programmer) have
       defined right-arrow as a  "special"  key,  so that for all
       fields, except  the  form's  last  field,  regular  action
       should occur, but on the last field of a form you  will do
       something special.  For regular  action  to  occur (right-
       arrow movement), make sure TKACCEPT=True.  In other words,
       Accept the user keystroke  by  letting  Paradox do what it
       would  normally  do.   However, when on  the  form's  last
       field, assign  TKACCEPT  to  False  assuring  that  normal
       right-arrow  action will not occur following your  special
       action.  The default value of TKACCEPT is True.










































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