F4 help in ALV grid, how to check the entries?

Question

Hello,
I have created F4 help on the cells in a ALV using OO ABAP. The F4 Help works fine and the user can select the entries from it. BUt in F4 help, the user can manually enter values also.
I want to either disallow the user the enter values manually or validate his entries and ask him to choose from F4 only.
How to achieve this??

Answer 1

Use this in Top Include
class local_event_handler definitin deferred.
data handler type ref to local_event_handler
After ALV Grid, register the edit event as shown below after the SET_TABLE_FOR_FIRST_DISPLAY and also set the handler as event handler
if handler is initial.
  create object handler.
endif.
set handler handler->handle_data_changed
                                                for main_grid. " Main Grid is your ALV Grid
call method main_grid->register_edit_event
      exporting
        i_event_id = cl_gui_alv_grid=>mc_evt_modified.
Class Definition / Implementation
class local_event_handler definition.
  public section.
    methods
        handle_data_changed
           for event data_changed of cl_gui_alv_grid
             importing er_data_changed.
    methods
       local_event_handler .
endclass.                    "local_event_handler DEFINITION
class local_event_handler implementation.
  method local_event_handler.
    " do nothing
  endmethod.                    "llocal_event_handler
  method handle_data_changed.
    read table er_data_changed->mt_mod_cells into ls_mod_cell index 1.
    perform handle_data_changed using er_data_changed.
    " ls_mod_cell-row_id contains the row number that changed. More details in er_data_changed
  endmethod.                    "handle_data_changed
endclass.                  "handle_btn_click