Events in ALV tree based on class CL_SALV_TREE

This reports helps to investigate events fired in ALV tree based on class CL_SALV_TREE. Just start this report in your system and play with it. It should stop in the debugger when an event is fired.

If you would like to process clicks on hierarchy nodes (simmilar as hotspot clicks on cells in tables) consider use of event DOUBLE_CLICK or LINK_CLICK (you have to set item for node to use LINK_CLICK).

To investigate KEYPRESS event, focus the item and press F1, F4 or ENTER.
REPORT zkmalve3.

TYPES:
* Types for structure and table of tree data
  BEGIN OF ts_data,
    node     TYPE string,
    descript TYPE string,
  END OF ts_data,
  tt_data  TYPE TABLE OF ts_data,

* Types for structure and table of tree hierarchy
  BEGIN OF ts_hier,
    node     TYPE string,
    parent   TYPE string,
    key      TYPE salv_de_node_key,
  END OF ts_hier,
  tt_hier  TYPE TABLE OF ts_hier.

DATA:
  gt_data  TYPE tt_data, " Tree data
  gt_hier  TYPE tt_hier. " Tree hierarchy

*----------------------------------------------------------------------*
*       CLASS cl_event_handler DEFINITION
*----------------------------------------------------------------------*
CLASS cl_event_handler DEFINITION.

  PUBLIC SECTION.

    CLASS-METHODS on_before_salv_function         " BEFORE_SALV_FUNCTION
      FOR EVENT if_salv_events_functions~before_salv_function
        OF cl_salv_events_tree
          IMPORTING e_salv_function.

    CLASS-METHODS on_after_salv_function          " AFTER_SALV_FUNCTION
      FOR EVENT if_salv_events_functions~before_salv_function
        OF cl_salv_events_tree
          IMPORTING e_salv_function.

    CLASS-METHODS on_added_function               " ADDED_FUNCTION
      FOR EVENT if_salv_events_functions~added_function
        OF cl_salv_events_tree
          IMPORTING e_salv_function.

    CLASS-METHODS on_top_of_page                  " TOP_OF_PAGE
      FOR EVENT if_salv_events_list~top_of_page
        OF cl_salv_events_tree
          IMPORTING r_top_of_page
                    page
                    table_index.

    CLASS-METHODS on_end_of_page                  " END_OF_PAGE
      FOR EVENT if_salv_events_list~end_of_page
        OF cl_salv_events_tree
          IMPORTING r_end_of_page
                    page.

    CLASS-METHODS on_double_click                 " DOUBLE_CLICK
      FOR EVENT if_salv_events_tree~double_click
        OF cl_salv_events_tree
          IMPORTING node_key
                    columnname.

    CLASS-METHODS on_link_click                   " LINK_CLICK
      FOR EVENT if_salv_events_tree~link_click
        OF cl_salv_events_tree
          IMPORTING columnname
                    node_key.

    CLASS-METHODS on_keypress                     " KEYPRESS
      FOR EVENT if_salv_events_tree~keypress
        OF cl_salv_events_tree
          IMPORTING node_key
                    columnname
                    key.

    CLASS-METHODS on_checkbox_change              " CHECKBOX_CHANGE
      FOR EVENT if_salv_events_tree~checkbox_change
        OF cl_salv_events_tree
          IMPORTING columnname
                    node_key
                    checked.

    CLASS-METHODS on_expand_empty_folder          " EXPAND_EMPTY_FOLDER
      FOR EVENT if_salv_events_tree~expand_empty_folder
        OF cl_salv_events_tree
          IMPORTING node_key.
ENDCLASS.                    "cl_event_handler DEFINITION

*----------------------------------------------------------------------*
*       CLASS cl_event_handler IMPLEMENTATION
*----------------------------------------------------------------------*
CLASS cl_event_handler IMPLEMENTATION.

  METHOD on_before_salv_function.
    BREAK-POINT.
  ENDMETHOD.                    "on_before_salv_function

  METHOD on_after_salv_function.
    BREAK-POINT.
  ENDMETHOD.                    "on_after_salv_function

  METHOD on_added_function.
    BREAK-POINT.
  ENDMETHOD.                    "on_added_function

  METHOD on_top_of_page.
    BREAK-POINT.
  ENDMETHOD.                    "on_top_of_page

  METHOD on_end_of_page.
    BREAK-POINT.
  ENDMETHOD.                    "on_end_of_page

  METHOD on_double_click.
    BREAK-POINT.
  ENDMETHOD.                    "on_double_click

  METHOD on_link_click.
    BREAK-POINT.
  ENDMETHOD.                    "on_link_click

  METHOD on_keypress.
    BREAK-POINT.
  ENDMETHOD.                    "on_keypress

  METHOD on_checkbox_change.
    BREAK-POINT.
  ENDMETHOD.                    "on_checkbox_change

  METHOD on_expand_empty_folder.
    BREAK-POINT.
  ENDMETHOD.                    "on_expand_empty_folder
ENDCLASS.                    "cl_event_handler IMPLEMENTATION

START-OF-SELECTION.

* Read the tree data and hierarchy
  PERFORM scan_hier CHANGING gt_data gt_hier.

* Display tree
  PERFORM display_alv_tree.

*&---------------------------------------------------------------------*
*&      Form  scan_hier
*&---------------------------------------------------------------------*
FORM scan_hier CHANGING pt_data   TYPE tt_data
                        pt_hier   TYPE tt_hier.

  DATA:
    ls_data  TYPE ts_data,
    ls_hier  TYPE ts_hier.

  ls_data-node = 'A'.   ls_data-descript = 'Root'.   APPEND ls_data TO pt_data.
  ls_data-node = 'B1'.  ls_data-descript = 'Node'.   APPEND ls_data TO pt_data.
  ls_data-node = 'B2'.  ls_data-descript = 'Item'.   APPEND ls_data TO pt_data.
  ls_data-node = 'C1'.  ls_data-descript = 'Item'.   APPEND ls_data TO pt_data.
  ls_data-node = 'C2'.  ls_data-descript = 'Item'.   APPEND ls_data TO pt_data.
  ls_data-node = 'C3'.  ls_data-descript = 'Item'.   APPEND ls_data TO pt_data.
  ls_data-node = 'C4'.  ls_data-descript = 'Item'.   APPEND ls_data TO pt_data.

  ls_hier-node = 'A'.   ls_hier-parent   = ''.       APPEND ls_hier TO pt_hier.
  ls_hier-node = 'B1'.  ls_hier-parent   = 'A'.      APPEND ls_hier TO pt_hier.
  ls_hier-node = 'B2'.  ls_hier-parent   = 'A'.      APPEND ls_hier TO pt_hier.
  ls_hier-node = 'C1'.  ls_hier-parent   = 'B1'.     APPEND ls_hier TO pt_hier.
  ls_hier-node = 'C2'.  ls_hier-parent   = 'B1'.     APPEND ls_hier TO pt_hier.
  ls_hier-node = 'C3'.  ls_hier-parent   = 'B1'.     APPEND ls_hier TO pt_hier.
  ls_hier-node = 'C4'.  ls_hier-parent   = 'B1'.     APPEND ls_hier TO pt_hier.
ENDFORM.                    "scan_hier

*&---------------------------------------------------------------------*
*&      Form  display_alv_tree
*&---------------------------------------------------------------------*
FORM display_alv_tree.

  DATA:
    lt_empty         TYPE tt_data,
    ls_data          TYPE ts_data,
    ls_hier          TYPE ts_hier,
    lv_text          TYPE lvc_value,
    lv_key           TYPE salv_de_node_key,
    lo_tree          TYPE REF TO cl_salv_tree,
    lo_nodes         TYPE REF TO cl_salv_nodes,
    lo_node          TYPE REF TO cl_salv_node,
    lo_item          TYPE REF TO cl_salv_item,
    lo_columns       TYPE REF TO cl_salv_columns,
    lo_column        TYPE REF TO cl_salv_column,
    lo_tree_settings TYPE REF TO cl_salv_tree_settings,
    lo_events        TYPE REF TO cl_salv_events_tree.

  FIELD-SYMBOLS:
    <fs_hier> TYPE ts_hier.

  TRY.
*     1. Create instance with an empty table
      CALL METHOD cl_salv_tree=>factory
        IMPORTING
          r_salv_tree = lo_tree
        CHANGING
          t_table     = lt_empty.

      lo_events = lo_tree->get_event( ).
      SET HANDLER cl_event_handler=>on_before_salv_function FOR lo_events.
      SET HANDLER cl_event_handler=>on_after_salv_function FOR lo_events.
      SET HANDLER cl_event_handler=>on_added_function FOR lo_events.
      SET HANDLER cl_event_handler=>on_top_of_page FOR lo_events.
      SET HANDLER cl_event_handler=>on_end_of_page FOR lo_events.
      SET HANDLER cl_event_handler=>on_double_click FOR lo_events.
      SET HANDLER cl_event_handler=>on_link_click FOR lo_events.
      SET HANDLER cl_event_handler=>on_keypress FOR lo_events.
      SET HANDLER cl_event_handler=>on_checkbox_change FOR lo_events.
      SET HANDLER cl_event_handler=>on_expand_empty_folder FOR lo_events.

*     Add key ENTER to raise KEYPRESS event, default keys are F1 and F4
*     (Attention: item has to be focused to send this event)
      CALL METHOD lo_events->add_key_for_keypress( key = if_salv_c_keys=>enter ).

*     2. Add the nodes to the tree and set their relations
      lo_nodes = lo_tree->get_nodes( ).

      LOOP AT gt_hier ASSIGNING <fs_hier>.

        IF <fs_hier>-parent = ''.
*         Add the node as root
          lo_node = lo_nodes->add_node(
            related_node = ''
            relationship = if_salv_c_node_relation=>parent ).
        ELSE.
*         Read the ALV key of parent node and add as a child
          READ TABLE gt_hier INTO ls_hier
            WITH KEY node = <fs_hier>-parent.
          lo_node = lo_nodes->add_node(
            related_node = ls_hier-key
            relationship = if_salv_c_node_relation=>last_child ).
        ENDIF.

*       Save the ALV internal key
        <fs_hier>-key = lo_node->get_key( ).

*       Add the data of the tree
        READ TABLE gt_data INTO ls_data
          WITH KEY node = <fs_hier>-node.
        lo_node->set_data_row( ls_data ).
        lv_text = ls_data-node.
        lo_node->set_text( lv_text ).

        CASE <fs_hier>-node.
          WHEN 'C2'.
*           Set node as link
*           in such case, single click on node fires the event LINK_CLICK
*           without this setting, double click on node fires the event DOUBLE_CLICK
            lo_item = lo_node->get_hierarchy_item( ).
            lo_item->set_type( if_salv_c_item_type=>link ).
          WHEN 'C3'.
*           Set node as button
            lo_item = lo_node->get_hierarchy_item( ).
            lo_item->set_type( if_salv_c_item_type=>button ).
          WHEN 'C4'.
*           Set node as checkbox
            lo_item = lo_node->get_hierarchy_item( ).
            lo_item->set_type( if_salv_c_item_type=>checkbox ).
        ENDCASE.
      ENDLOOP.

*     Do some final format tasks
      lo_columns = lo_tree->get_columns( ).
      lo_columns->set_optimize( abap_true ).
      lo_column = lo_columns->get_column( 'NODE' ).
      lo_column->set_visible( abap_false ).
      lo_tree_settings = lo_tree->get_tree_settings( ).
      lo_tree_settings->set_hierarchy_header( 'Node' ).
      lo_nodes->expand_all( ).

*     Display Tree
      lo_tree->display( ).

    CATCH cx_salv_not_found. " for cl_salv_columns=>get_column
      WRITE: / 'Error: ALV Ausnahme CX_SALV_NOT_FOUND'.
      STOP.

    CATCH cx_salv_error.     " for cl_salv_tree=>factory
      WRITE: / 'Error: ALV Ausnahme CX_SALV_ERROR'.
      STOP.
  ENDTRY.
ENDFORM.                    "display_alv_tree
See other related notes in my infodepot:
ALV tree based on class CL_SALV_TREE Events in the object oriented ALV based on class CL_GUI_ALV_GRID Events in the object oriented ALV based on class CL_SALV_TABLE
Full list of examples in my infodepot

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