Something that occurs quite often to me is the following.
I need to create a new object of some type. But I don't know whether it is a case class/has a factory method or I have to instantiate it using 'new'. Actually I don't do this reasoning. What I do is trying to type the class name (using camel-case completion). Then I begin hitting ctrl+space and getting upset. The problem is that, the class name won't show up until I prepend a 'new' if the class has no companion apply method.
frame.getContentPane.add(jb <- doesn't work
frame.getContentPane.add(new jb <- works and proposes JButton
Hit ctrl+space to get the completion for JButton. Everyone knows that JButton doens't have a nice factory method, but you know what I mean?
Maybe it's possible to search also the "constructors" that need a new, even if none is given? Of course you automatically need to insert the 'new' if the completion is chosen.
But I think you should be carefull with making the completion more general, since we had the problem some weeks ago, that there were to many completion proposals (ones that you didn't want). Maybe put it into an option for testing and then use it if it works out well.