Code Completion in QScintilla

[fullmetalcoder]

I get from my compiler all I need to put in the ListBox of the code completion

Then using QScintilla may not be needed... You can simply use a QCompleter on a QTextEdit (there's an example of such a combination in Qt)

Tell me where I can get the information I need, anything will by useful.

There should be some docs distributed along QScintilla... In case they are not there you could generate them with doxygen or consult the online docs.