Screen object sample code

Screen class and Screenfield class example code

The following program defines a screen application that displays and scrolls through a set of records. The records are initially obtained via the Fast/Unload User Language Interface from a RecordSet object to a Stringlist, though this is incidental to the main application details which feature multiple methods from the Screen and ScreenField classes.

R SCRNSTBL 10000
b
%rs is object recordSet in file tomdb
%ft is object fastUnloadTask
%listi is object stringList
%listo is object stringList
%listr is object stringList
%rc float
%i float
%j float
%title is string len 255
%msg is string len 100

 * obtain the records that will be displayed 

find records to %r
end find
%listi = new
%listo = new
%listr = new
text to %listi
FOR EACH RECORD
  IF TOTAL PREMIUM EXISTS THEN
    PUT FULLNAME AS STRING(24)
    PUT STATE AS STRING(24)
    PUT '$'
    PUT TOTAL PREMIUM AS STRING
    PUT '.00'
  END IF
  OUTPUT
END FOR
end text
%rc = %rs:fastUnload(%listi, %listo, %listr, parameters='NEBUFF=2')
%sscr    is object screen
%scrtop  is object screenField
%scrfcmd is object screenField
%scrfmsg is object screenField
%scrfPF  is object screenField
%sscral  is arraylist of object screenField
%sscr   = new
%sscral = new
 
 * separately format top three rows and the bottom row
 
%scrtop = %sscr:addField(row=1, column=1, color=yellow, -
           width=%sscr:columns - 1, highlight=none)
%scrtop:value = $center('August Listing', %sscr:columns - 1)
%scrfcmd = %sscr:addField(row=2, column=1, width=%sscr:columns - 1, color=yellow)
%scrfmsg = %sscr:addField(row=3, column=1, width=%sscr:columns - 1, color=yellow)
%scrfcmd:setCursor
%scrfPF  = %sscr:addField(row=%sscr:rows, width=%sscr:columns - 2, column=1, -
           highlight=reverse, color=white)
%title   = 'PF1=Backward PF2=Forward PF3=Quit'
%scrfPF:value = $center(%title, %sscr:columns - 2)
 
 * format the data display rows and store in arraylist 
 
 for %i from 1 to %sscr:rows - 5
   %sscral:add(%sscr:addField(row=%i + 3, column=1, width=%sscr:columns - 1, color=green))
   if $mod(%i - 1, 5) = 0 then
     %sscral(%i):highlight = underline
     %sscral(%i):color = turquoise
   end if
end for
 
 * populate the data display arraylist with unloaded data
 
%i = 1
%j = 0
repeat forever
  for %i from %i to %listo:count
    %j = %j + 1
    if %j > %sscral:count then
      loop end
    end if
    %sscral(%j):value = $lowcase(%listo(%i))
  end for
  
  for %j from %j to %sscral:count
    %sscral(%j):value = ''
  end for
 
 * display screen and process user response
 
  %sscr:read
  %scrfmsg:value = ''
  jump to (f1, f2, f3) %sscr:actionKey:toNumber
  if %sscr:actionKey:toNumber then
    %scrfmsg:value = 'Only PF1-PF3 are valid keys'
    %scrfmsg:color = red
    %scrfmsg:highlight = reverse
  else
    %scrfmsg:value = 'Enter key pressed'
    %scrfmsg:color = white
    %scrfmsg:highlight = none
  end if
  jump to hl
f1:
  %i = %i - (%sscral:count * 2)
  if %i < 1 then
    %i = %listo:count - %sscral:count
    if %i < 1 then
      %i = 1
    end if
    %scrfmsg:value = 'Wrapped...'
     %scrfmsg:color = white
     %scrfmsg:highlight = none
  end if
  %j = 0
  jump to hl
f2:
  if %i >= %listo:count then
    %i = 1
    %scrfmsg:value = 'Wrapped...'
    %scrfmsg:color = white
    %scrfmsg:highlight = none
  end if
  %j = 0
  jump to hl
f3:
  loop end
hl:
end repeat
end 

Note: The above sample shows many of the Screen and Screenfield class features, coded in a very procedural way. You can also use the Screen class to create your own kind of screen in a fully object-oriented way. See the example of a locally-written screen class.

See also

• The "Screen classes" page
• How to use Model 6, or dynamically sized screens, in Model 204
• Notation conventions used in Janus SOAP documentation