[ABAP] ALV-Grid auf dem Selektionsbildschirm anzeigen, Klick-Events abfangen, Selektions-Parameter setzen

DATA: o_dock TYPE REF TO cl_gui_docking_container.
DATA: o_alv TYPE REF TO cl_gui_alv_grid.
DATA: it_t001 TYPE STANDARD TABLE OF t001.
DATA: lv_temp TYPE string.

SELECTION-SCREEN BEGIN OF BLOCK var WITH FRAME TITLE title1.
PARAMETERS: p_param1 TYPE string.
SELECTION-SCREEN END OF BLOCK var.

CLASS lcl_events DEFINITION.
  PUBLIC SECTION.
    METHODS: on_single_click FOR EVENT hotspot_click OF cl_gui_alv_grid
      IMPORTING
        e_row_id  " obsolet, stattdessen es_row_no benutzen
        es_row_no
        e_column_id.
    METHODS: on_double_click FOR EVENT double_click OF cl_gui_alv_grid
      IMPORTING
        e_row e_column.
ENDCLASS.

CLASS lcl_events IMPLEMENTATION.
* Doppel-Klick für Hotspot-Felder
  METHOD on_double_click.
    IF e_row > 0.
      lv_temp = it_t001[ e_row ]-butxt.
    ENDIF.
  ENDMETHOD.

* Single-Klick für Hotspot-Felder
  METHOD on_single_click.
    IF es_row_no-row_id > 0.
      lv_temp = it_t001[ es_row_no-row_id ]-butxt.
    ENDIF.
  ENDMETHOD.
ENDCLASS.

INITIALIZATION.

  title1 = 'Selektion'.

* Daten holen
  SELECT * FROM t001 INTO TABLE it_t001.

* Docking-Container erzeugen
  o_dock = NEW #( side = cl_gui_docking_container=>dock_at_left
                  ratio = 20 ).

* ALV-Grid erzeugen
  o_alv = NEW #( i_parent = o_dock
                 i_appl_events = abap_true ).

* Eventhandler setzen
  DATA(o_events) = NEW lcl_events( ).
  SET HANDLER o_events->on_double_click FOR o_alv.
  SET HANDLER o_events->on_single_click FOR o_alv.

* Layout anpassen
  DATA(lv_layout) = VALUE lvc_s_layo( grid_title = 'Auswahl mit Doppelklick:'
                                      no_toolbar = abap_false
                                      smalltitle = abap_true
                                      zebra      = abap_true ).

* ALV-Grid initialisieren
  o_alv->set_table_for_first_display( EXPORTING
                                        i_structure_name = 'T001'
                                        i_save           = space
                                        is_layout        = lv_layout
                                      CHANGING
                                        it_outtab        = it_t001 ).

* Feldkatalog holen
  DATA: it_fcat TYPE lvc_t_fcat.
    
  o_alv->get_frontend_fieldcatalog( IMPORTING
                                      et_fieldcatalog = it_fcat ).

* Hotspot für die Spalte 'BUTXT' aktivieren, damit Event handle_single_click abgefangen werden kann
  LOOP AT it_fcat ASSIGNING FIELD-SYMBOL(<fcat>).
    CASE <fcat>-fieldname.
      WHEN 'BUTXT'.
        <fcat>-hotspot = abap_true.
    ENDCASE.
  ENDLOOP.

* Feldkatalog speichern
  o_alv->set_frontend_fieldcatalog( it_fieldcatalog = it_fcat ).

* ALV-Grid anzeigen
  o_alv->refresh_table_display( ).

AT SELECTION-SCREEN OUTPUT.
* Selektion an Parameter geben
  p_param1 = lv_temp.

START-OF-SELECTION.
  WRITE: / 'Gewählter Parameter: ', p_param1.