REPORT z_demo_alv_event_exit_1.
*>*********************************************************************
* This report reads and displays data from table TRDIR,               *
* using the FM : REUSE_ALV_LIST_DISPLAY                               *
* The columns are displayed in the same order than the Sort Order     *
* There is an underline if the sort is by UNAM or UDAT                *
*---------------------------------------------------------------------*
* Author : Michel PIOUD                                               *
* Email : mpioud@yahoo.fr  HomePage : http://www.geocities.com/mpioud *
***********************************************************************

SELECTION-SCREEN :
BEGIN OF LINE,COMMENT 5(27) v_1 FOR FIELD p_max.            "#EC NEEDED
PARAMETERS p_max(3) TYPE n DEFAULT '99' OBLIGATORY.
SELECTION-SCREEN END OF LINE.

TYPE-POOLS slis.                       " ALV Global Types

*---------------------------------------------------------------------*
TYPES:
  BEGIN OF ty_trdir,
    name TYPE trdir-name,             " ABAP program name
    cnam TYPE trdir-cnam,             " Created by
    cdat TYPE trdir-cdat,             " Created on
    unam TYPE trdir-unam,             " Last changed by
    udat TYPE trdir-udat,             " Last changed on
  END OF ty_trdir.

*---------------------------------------------------------------------*
DATA:
  gt_trdir TYPE TABLE OF ty_trdir.       " Data displayed

*---------------------------------------------------------------------*
INITIALIZATION.

  v_1 = 'Maximum of records to read'.

*---------------------------------------------------------------------*
START-OF-SELECTION.

  PERFORM f_read_data.

  PERFORM f_display_data.

*---------------------------------------------------------------------*
*       Form  f_read_data
*---------------------------------------------------------------------*
FORM f_read_data.

  SELECT name cnam cdat unam udat
    INTO TABLE gt_trdir
      UP TO p_max ROWS
    FROM trdir
   WHERE name LIKE 'Z%'.

ENDFORM.                               " F_READ_DATA
*---------------------------------------------------------------------*
*      Form  f_display_data
*---------------------------------------------------------------------*
FORM f_display_data.

* Macro definition
  DEFINE m_fieldcat.
    add 1 to ls_fieldcat-col_pos.
    ls_fieldcat-fieldname = &1.
    ls_fieldcat-ref_tabname = 'TRDIR'.
    append ls_fieldcat to lt_fieldcat.
  END-OF-DEFINITION.

  DEFINE m_event_exit.
    clear ls_event_exit.
    ls_event_exit-ucomm = &1.
    ls_event_exit-after = 'X'.
    append ls_event_exit to lt_event_exit.
  END-OF-DEFINITION.

  DATA :
    ls_layout     TYPE slis_layout_alv,
    ls_fieldcat   TYPE slis_fieldcat_alv,
    lt_fieldcat   TYPE slis_t_fieldcat_alv,
    lt_event_exit TYPE slis_t_event_exit,
    ls_event_exit TYPE slis_event_exit.

* Build Field Catalog
  m_fieldcat 'NAME'.
  m_fieldcat 'CNAM'.
  m_fieldcat 'CDAT'.
  m_fieldcat 'UNAM'.
  m_fieldcat 'UDAT'.

* Build Event Exit Table
  m_event_exit '&OUP'.                 " Sort up
  m_event_exit '&ODN'.                 " Sort Down

  ls_layout-zebra = 'X'.

  CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
       EXPORTING
            i_callback_program      = sy-cprog
            i_callback_user_command = 'USER_COMMAND'
            is_layout               = ls_layout
            it_fieldcat             = lt_fieldcat
            it_event_exit           = lt_event_exit
       TABLES
            t_outtab                = gt_trdir.

ENDFORM.                               " F_DISPLAY_DATA
*---------------------------------------------------------------------*
*       FORM USER_COMMAND                                             *
*---------------------------------------------------------------------*
FORM user_command USING u_ucomm     TYPE syucomm
                        us_selfield TYPE slis_selfield.     "#EC CALLED

  CASE u_ucomm.
    WHEN '&OUP' OR '&ODN'.             " Sort
      PERFORM f_modif_fieldcat.
      us_selfield-refresh = 'X'.
  ENDCASE.

ENDFORM.                               " USER_COMMAND
*---------------------------------------------------------------------*
*       Form  F_MODIF_FIELDCAT
*---------------------------------------------------------------------*
FORM f_modif_fieldcat.

  DATA:
    lt_fieldcat TYPE slis_t_fieldcat_alv,
    lt_sort     TYPE slis_t_sortinfo_alv.

  FIELD-SYMBOLS :
    <sort>     TYPE slis_sortinfo_alv,
    <fieldcat> TYPE slis_fieldcat_alv.

* Read current ALV list information
  CALL FUNCTION 'REUSE_ALV_LIST_LAYOUT_INFO_GET'
       IMPORTING
            et_fieldcat   = lt_fieldcat
            et_sort       = lt_sort
       EXCEPTIONS
            no_infos      = 1
            program_error = 2
            OTHERS        = 3.

  IF sy-subrc NE 0.
    EXIT.
  ENDIF.

  CHECK NOT lt_sort[] IS INITIAL.

* Fieldcat modification
  DESCRIBE TABLE lt_fieldcat.

  LOOP AT lt_fieldcat ASSIGNING <fieldcat>.
    <fieldcat>-col_pos = <fieldcat>-col_pos + sy-tfill.
  ENDLOOP.

  LOOP AT lt_fieldcat ASSIGNING <fieldcat>.
    READ TABLE lt_sort ASSIGNING <sort>
                        WITH KEY fieldname = <fieldcat>-fieldname.
    CHECK sy-subrc EQ 0.
    <fieldcat>-col_pos = <sort>-spos.
  ENDLOOP.

  SORT lt_fieldcat BY col_pos.
  LOOP AT lt_fieldcat ASSIGNING <fieldcat>.
    <fieldcat>-col_pos = sy-tabix.
  ENDLOOP.

* Underline if the sort is by UNAM or UDAT
  READ TABLE lt_sort ASSIGNING <sort> INDEX 1.
  IF <sort>-fieldname = 'UNAM'  OR
     <sort>-fieldname = 'UDAT'.
    <sort>-group = 'UL'.
  ENDIF.

  CALL FUNCTION 'REUSE_ALV_LIST_LAYOUT_INFO_SET'
       EXPORTING
            it_sort     = lt_sort
            it_fieldcat = lt_fieldcat.

ENDFORM.                               " F_MODIF_FIELDCAT
******** END OF PROGRAM Z_DEMO_ALV_EVENT_EXIT_1 ***********************