In this tutorial I’ll show how to enable only the specific cells of a grid to be editable.

First I’ll prepare some demonstration data. It will be a list of materials and their maintenance status. If status is set to ‘A’ we would like to disable editing of status in the grid.

Now we create a function group with screen (i.e. 0200) where we’ll draw our ALV grid.
In the screen layout editor create a custom container and name it i.e. GO_GRID_CONTAINER.
Also create a custom PF-STATUS with two functions: UPDATE and REFRESH

The flow logic for the screen will be simple:

PROCESS BEFORE OUTPUT.
  MODULE pbo_0200.
*
PROCESS AFTER INPUT.
  MODULE pai_0200.

The PBO_0200 module is used to gather data, create field catalog and display the ALV. Here follows its code

MODULE pbo_0200 OUTPUT.
  DATA:
    ls_layout  TYPE lvc_s_layo,
    ls_variant TYPE disvariant.

  FIELD-SYMBOLS:
    <fs_fcat> TYPE lvc_s_fcat.

* In this user status we create two functions:
* UPDATE - save all changes and refresh grid
* REFRESH - refresh grid with data from Z-table
  SET PF-STATUS 'PF_STATUS'.

* Initial creation of container and grid
  IF gr_container IS INITIAL.
    CREATE OBJECT gr_container
      EXPORTING
*       This is reference to the object we made in Layout editor
        container_name = 'GO_GRID_CONTAINER'.

*   Parent is our container created above
    CREATE OBJECT gr_grid
      EXPORTING
        i_parent = gr_container.

*   Simplest field catalog creation
    CALL FUNCTION 'LVC_FIELDCATALOG_MERGE'
      EXPORTING
        i_structure_name = 'ZMATSTAT'
      CHANGING
        ct_fieldcat      = gt_fieldcat.

*   !!! IMPORTANT !!!
*   We have to mark all required columns as editable !!!
    READ TABLE gt_fieldcat ASSIGNING <fs_fcat> WITH KEY fieldname = 'PSTAT'.
    <fs_fcat>-edit = abap_true.

*   Load data from database and mark the
*   appropriate field as R/O
    PERFORM reload_data.

*   Set the field name carrying info about cell styles (RW / RO)
    ls_layout-stylefname = 'CELL_STYLES'.

    ls_variant-report   = sy-repid.
    ls_variant-username = sy-uname.

*   !!! IMPORTANT !!!
*   We register the ENTER event so the manual changes
*   are propagated back to GT_DATA
    gr_grid->register_edit_event( i_event_id = cl_gui_alv_grid=>mc_evt_enter ).

*   Draw the ALV
    gr_grid->set_table_for_first_display(
       EXPORTING
         is_layout             = ls_layout
         is_variant            = ls_variant
         i_save                = 'A'
         i_default             = 'X'
       CHANGING
         it_fieldcatalog       = gt_fieldcat
         it_outtab             = gt_data ).
  ENDIF.
ENDMODULE.                 " PBO_0200  OUTPUT

Module PAI_0200 is used to process user interaction and here follows its code

MODULE pai_0200 INPUT.
  DATA:
    l_matstat    TYPE zmatstat.
  FIELD-SYMBOLS:
    <fs_data> LIKE LINE OF gt_data.

  CASE sy-ucomm.
    WHEN 'BACK' OR 'LEAVE' OR 'CANCEL'.
      SET SCREEN 0.

    WHEN 'UPDATE'.
*    Update DB Z-table
      LOOP AT gt_data ASSIGNING <fs_data> WHERE matnr IS NOT INITIAL.
        MOVE-CORRESPONDING <fs_data> TO l_matstat.
        MODIFY zmatstat FROM l_matstat.
      ENDLOOP.

*     Reload data database and mark the
*     appropriate fields as R/O
      PERFORM reload_data.
      gr_grid->refresh_table_display( ).

    WHEN 'REFRESH'.
      PERFORM reload_data.
      gr_grid->refresh_table_display( ).
  ENDCASE.
ENDMODULE.                 " PAI_0200  INPUT

The helper FORM RELOAD_DATA is used to gather data from database and mark the appropriate fields as read/only

FORM reload_data.
  DATA:
    l_lvc_s_styl TYPE lvc_s_styl.
  FIELD-SYMBOLS:
    <fs_data> LIKE LINE OF gt_data.

  CLEAR gt_data[].
* Read the data
  SELECT *
    INTO CORRESPONDING FIELDS OF TABLE gt_data
    FROM zmatstat.

* Loop over all rows of data and set PSTAT
* as R/O in case its value = 'A'
  LOOP AT gt_data
    ASSIGNING <fs_data>
    WHERE pstat = 'A'.

    l_lvc_styl-style = cl_gui_alv_grid=>mc_style_disabled.
    l_lvc_styl-fieldname = 'PSTAT'.

*   INSERT command MUST be used 
*   because field CELL_STYLES is a SORTED TABLE
    INSERT l_lvc_styl INTO TABLE <fs_data>-cell_styles.
  ENDLOOP.
ENDFORM.                    "reload_data

If we now call our screen from ABAP, we’ll get the following:

If we modify some data, change the value of PSTAT in some row to ‘A’ and save the changes:

…and data in database: