There seem to be any number of questions on OO and ALV grid none of which I suspect really give you the answers you are looking for so I've put together a program which gives you more or less EVERYTHING you could possibly want or need in the OO ALV grid including interactive data entry
it does basically the following
1) Build Dynamic ITAB with fields NOT defined in DDIC
2) Build Dynamic FieldCat. Table structure is obtained via
the new RTTI functionality
3) Add the CELL colour table as a deep structure to our dynamic table
so we can colour individual cells.
4) Inherit a class so protected attributes of class cl_gui_alv_grid
can be accessed
5) Add events so we can can program functionality when the user presses the ENTER key,
or selects an action from the toolbar.
6) Display one line of a grid from our dynamic table with some cells coloured.
6) Set the Grid editable.
7) if user enters data then colour cells of entered data.
8) show contents of new table after all data has been entered.
The code is in the following thread -- look for my post (james hawthorne)
Hopefully this is of use to you