Creating ToolBar buttons group in containers Using CL_GUI_TOOLBAR class

DATA : lr_toolbar TYPE REF TO cl_gui_toolbar,
lr_cust_cont TYPE REF TO cl_gui_custom_container,
lt_btn TYPE ttb_button,
ls_btn TYPE stb_button.

CALL SCREEN 0001.
*&---------------------------------------------------------------------*
*&      Module  CREATE_PFSTATUS  OUTPUT
*&---------------------------------------------------------------------*
MODULE create_pfstatus OUTPUT.
  SET PF-STATUS 'STATUS'.
ENDMODULE.                 " CREATE_PFSTATUS  OUTPUT
*&---------------------------------------------------------------------*
*&      Module  CREATE_TOOLBAR  OUTPUT
*&---------------------------------------------------------------------*
MODULE create_toolbar OUTPUT.
  IF lr_cust_cont IS NOT BOUND.
    CREATE OBJECT lr_cust_cont
      EXPORTING
        container_name = 'TOOLBAR'
        repid          = sy-repid
        dynnr          = sy-dynnr.

  ENDIF.

  IF lr_toolbar IS NOT BOUND.
    CREATE OBJECT lr_toolbar
      EXPORTING
        parent             = lr_cust_cont
        display_mode       = cl_gui_toolbar=>m_mode_horizontal " Display mode
        name               = 'Demo Toolbar'
      EXCEPTIONS
        cntl_install_error = 1
        cntl_error         = 2
        cntb_wrong_version = 3
        OTHERS             = 4.

  ENDIF.

  CLEAR : ls_btn.
  ls_btn-butn_type = '0'.
  ls_btn-function = 'TSAVE'.
  ls_btn-icon = '@2L@'.
  ls_btn-text = 'Save'.
  APPEND ls_btn TO lt_btn.

  CLEAR : ls_btn.
  ls_btn-butn_type = '3'. "Separator
  APPEND ls_btn TO lt_btn.

  CLEAR : ls_btn.
  ls_btn-butn_type = '0'.
  ls_btn-function = 'EDIT'.
  ls_btn-icon = '@TE@'.
  ls_btn-text = 'Edit'.
  APPEND ls_btn TO lt_btn.

  CLEAR : ls_btn.
  ls_btn-butn_type = '3'. " Separator
  APPEND ls_btn TO lt_btn.

  CLEAR : ls_btn.
  ls_btn-butn_type = '0'.
  ls_btn-function = 'TCANCEL'.
  ls_btn-icon = '@0W@'.
  ls_btn-text = 'Cancel'.
  APPEND ls_btn TO lt_btn.

  CALL METHOD lr_toolbar->add_button_group
    EXPORTING
      data_table       = lt_btn
    EXCEPTIONS
      dp_error         = 1
      cntb_error_fcode = 2
      OTHERS           = 3.

ENDMODULE.                 " CREATE_TOOLBAR  OUTPUT
*&---------------------------------------------------------------------*
*&      Module  HANDLE_USERACTION  INPUT
*&---------------------------------------------------------------------*
MODULE handle_useraction INPUT.
  CASE sy-ucomm.
    WHEN 'BACK' OR 'EXIT' OR 'CANCEL'.
      LEAVE TO SCREEN 0.
    WHEN OTHERS.
  ENDCASE.
ENDMODULE.                 " HANDLE_USERACTION  INPUT
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Screen flow logic.