Enable standard toolbar for ALV grid - toolbar

Question

I created a screen for displaying ALV output but I am not able to show standard toolbar buttons (save, exit, back, etc.).
Can any one suggest how to enable them?
DATA: it_zztstudent type STANDARD TABLE OF zztstudent,
it_fcat TYPE STANDARD TABLE OF lvc_s_fcat,
i_selected_rows TYPE lvc_t_row,
w_selected_rows type lvc_s_row,
it_modified type STANDARD TABLE OF zztstudent,
lw_modified type zztstudent,
lw_zztstudent type zztstudent,
w_variant TYPE disvariant,
o_docking type REF TO cl_gui_docking_container,
o_grid type ref to cl_gui_alv_grid.
FIELD-SYMBOLS: <fs_fieldcat> type lvc_s_fcat.
tables: zztstudent.
select-OPTIONS: sst_id for zztstudent-st_id.
select * from zztstudent
into table it_zztstudent
where st_id in sst_id.
if sy-subrc NE 0.
message e001(zmsgpr).
ENDIF.
call screen 9000.
module status_9000 OUTPUT.
if o_docking is initial.
set PF-STATUS 'ZSTATUS'.
set titlebar 'ZTITLE'.
"Creating Docking Container and grid
PERFORM create_object.
"filling the fieldcatalog table
PERFORM create_fieldcat.
"Modifying the fieldcatalog table
PERFORM modify_fieldcat.
"Registering edit
PERFORM register_edit.
"displaying the output
PERFORM display_output.
ENDIF.
endmodule.
MODULE user_command_9000 INPUT.
Data: lv_ucomm TYPE sy-ucomm.
lv_ucomm = sy-ucomm.
CASE lv_ucomm.
WHEN 'CANCEL' oR 'EXIT'.
PERFORM free_objects.
leave program.
WHEN 'BACK'.
PERFORM free_objects.
SET SCREEN '0'.
leave SCREEN.
WHEN 'SAVE'.
PERFORM save_database.
CALL METHOD o_grid->refresh_table_display.
ENDCASE.
ENDMODULE.
Form create_object.
"create docking container
create object o_docking
exporting
ratio = '95'.
if sy-subrc eq 0.
"create grid
create OBJECT o_grid
exporting
i_parent = o_docking.
endif.
ENDFORM.
FORM create_fieldcat.
CALL FUNCTION 'LVC_FIELDCATALOG_MERGE'
EXPORTING
* I_BUFFER_ACTIVE =
I_STRUCTURE_NAME = 'ZZTSTUDENT'
* I_CLIENT_NEVER_DISPLAY = 'X'
* I_BYPASSING_BUFFER =
* I_INTERNAL_TABNAME =
CHANGING
CT_FIELDCAT = IT_FCAT
EXCEPTIONS
INCONSISTENT_INTERFACE = 1
PROGRAM_ERROR = 2
OTHERS = 3
.
IF SY-SUBRC <> 0.
* Implement suitable error handling here
ENDIF.
ENDFORM.
"making the column as editable
FORM modify_fieldcat.
loop at it_fcat ASSIGNING <fs_fieldcat>.
CASE <fs_fieldcat>-fieldname.
WHEN 'ST_NAME'.
<fs_fieldcat>-edit = 'X'.
WHEN 'ST_CITY'.
<fs_fieldcat>-edit = 'X'.
ENDCASE.
ENDLOOP.
ENDFORM.
FORM register_edit.
call METHOD o_grid->register_edit_event
exporting
i_event_id = cl_gui_alv_grid=>mc_evt_modified.
ENDFORM.
FORM display_output.
w_variant-report = sy-repid.
call METHOD o_grid->set_table_for_first_display
EXPORTING
is_variant = w_variant
i_save = 'A'
CHANGING
it_outtab = it_zztstudent
IT_FIELDCATALOG = it_fcat
EXCEPTIONS
invalid_parameter_combination = 1
program_error = 2
too_many_lines = 3
others = 4.
if sy-subrc <> 0.
message e001(zmsgpr).
endif.
ENDFORM.
FORM free_objects.
call method o_grid->free
EXCEPTIONS
cntl_error = 1
cntl_system_error = 2
others = 3.
if sy-subrc <> 0.
message e001(zmsgpr).
endif.
call method o_docking->free
EXCEPTIONS
cntl_error = 1
cntl_system_error = 2
others = 3.
if sy-subrc <> 0.
message e001(zmsgpr).
endif.
ENDFORM.

Answer 1

First double click on set PF-STATUS 'ZSTATUS' on ZSTATUS and create object.
After that you will get here:
Click in functions Keys and add what code you want for each button.
Finally in a case statement, check if sy-ucomm has the value of the code you entered.

Answer 2

First you must create a method, in your class definition like this:
METHODS on_toolbar
FOR EVENT toolbar
OF cl_gui_alv_grid
IMPORTING e_object.
After that you must create an event object and there you must set the handler for the alvgrid object, like these:
IF gcl_container IS INITIAL.
CREATE OBJECT gcl_container
EXPORTING
container_name = 'CONTAINER'.
CREATE OBJECT gcl_grid
EXPORTING
i_parent = gcl_container.
"erstellt einen Handler der alle ereignisse aufnimmt
"created object and set a handler of all events
CREATE OBJECT gcl_event.
SET HANDLER gcl_event->on_toolbar
FOR gcl_grid.
ENDIF.
Hope it helps you. :)