Table control: Line selection single issue

Question

Hi experts,
I have created a table control and in the screen painter I have defined the line selection as "Single" for table control.
The table control can display upto 20 lines in a screen and i can select a single record only which pertains to my requirement. if I try to select two records it will not allow.
Issue: consider  i select a single record from the first 20 lines displayed in screen, then i scroll the records in the table control so that it displays the records from 21 to 40. if I select a single record now from line 21 to 40, the first record that i selected is not getting deselected. That is, totally two lines are getting selected.
How to overcome this issue
Thanks in advance
Regards
Anand

Answer 1

Ok
The "problem" is here:
Types: Begin of ty_ic,
  ic(20),
  desc(20),
  sel(1)                                 <--------------------------------
End of ty_ic.
You've ha a field for selected line and that field is used in table control definition as you've written:
"Note: wa_ic is the structure used in table control and wa_ic-sel is the mark field defined the table control attributes"
So you're using the structure WA_IC as header line of internal table IT_IC and also as input/put field of your table control (I mean the screen fields of table control are based on WA_IC).
You don't need any code in PBO to move the data from internal table to table control, because the headerline of IT_IC and field of table control are the same, infact you've implemented only the code in PAI to save the data from table control to IT_IC:
Loop at it_ic.
Modify it_ic from wa_ic index tc_ic-current_line
Endloop
t's a good solution if it needs to transfer all data to table control automatically: it doesn't need any code in PBO
but, of course, there'll be a problem when you don't need to display something, in this case you have to think a solution, I mean you have to write a code in order to avoid to display those data.
It's the case of the selected line: in your situation all selected lines keep the selection, because the code to clear IT_IC-SEL is missing: only the user can deselect a line, but if he doesn't do it, the line will remain selected after navigation.
So you make to be sure to clear all selected lines are not displayed.
You need to create a code in PAI out of the loop of table control where you clear the flag SEL, in order to do it you need to consider:
- The index of the first record displayed in table control is stored in field TC_IC-TOP_LINE
- The index of the last record displayed in table control can be calculated: the variable SY-LOOPC indicates how many rows can be displayed in table control, so the last record will be: TC_IC-TOP_LINE + SY-LOOPC.
So you need to clear the field SEL for all records not displayed, a code like this:
PROCESS PAI.
  LOOP AT IT_IC.
     MODULE GET_LOOPC.
  ENDLOOP.
  MODULE CLEAR_SEL.
  MODULE GET_LOOPC..
      TOT_LINE_DISPLAYED = SY-LOOPC.
  ENDMODULE
  MODULE CLEAR_SEL.
* Here you need to clear the selection of the records before of TOP_LINE
       IF TC_IC-TOP_LINE > 1.
          LOOP AT IT_IC INTO WA_IC  TO TC_IC-TOP_LINE.
             CLEAR WA_IC-SEL.
             MODIFY IT_IC FROM WA_IC.
          ENDLOOP.
     ENDIF.
* Here you need to clear the selection of the records after the last one:
      LAST_INDEX = TOT_LINE_DISPLAYED + TC_IC-TOP_LINE.
     DESCRIBE TABLE IT_IC LINES SY-TABIX,
     IF SY-TABIX > LAST_INDEX.
          LOOP AT IT_IC INTO WA_IC  FROM LAST_INDEX.
             CLEAR WA_IC-SEL.
             MODIFY IT_IC FROM WA_IC.
          ENDLOOP.
     ENDIF.
  ENDMODULE.