Why cl_gui_alv_grid with subtotals doesn't show the collapse/expand icon on subtotals?

[Sandra_Rossi]

The collapse/expand button  is not shown by the program:

Expected:

What are the possible causes?

NB: in case you ask, all amounts are zero in the screenshot but there are lines above with non-zero amounts.

[Sandra_Rossi · Accepted solution]

Here are the possible causes concerning CL_GUI_ALV_GRID:

1. IS_LAYOUT-NO_TOTEXP = 'X' (parameter of method SET_TABLE_FOR_FIRST_DISPLAY)
2. The ALV Grid is generally set to editable (IS_LAYOUT-EDIT = 'X' or method SET_READY_FOR_INPUT( 1 )). See here for more information: https://community.sap.com/t5/application-development-discussions/alv-grid-control-subtotal-collapse/.... Note that the general editable flag of the grid may be set while the ALV grid doesn't seem to contain any editable field (all columns with IT_FIELDCATALOG-EDIT = ' ' or the style field (field of type LVC_T_STYL in the ALV table, whose name is to be passed to IS_LAYOUT-STYLEFNAME) contains MC_STYLE_DISABLED).

If there are other possibilities, please add your answer. Thank you!