Geany's auto-completion feature is awesome and very quick, and I've actually started using it. However my only beef with it is that for a file to be indexed by auto-completion, it must be open - which is impractical if you're working on a large project. Because auto-completion there is *really* helpful, but keeping all of the headers isn't.
Could an option be made to add files to the auto-completion for indexing for given projects? So you don't have to keep the files open, but geany would still know about them.