This is not the first time that I would have needed that...
In the example bellow I would love to have all set*Listeners listed so I wouldn't have to scroll trough all the houndreds of methods to find the listener setter I need.
Is there a way to do that, or any alternative that lets me search trough the content assist results more effectively? (Allowing a wildcard character would be a really good start)
The Eclipse Code Recommenders project includes subwords completion which seems to be what you are looking for. In your example, it will find setListener when completing on sLis. You don't even have to type in a wildcard.
Keep in mind that subwords completion is not activated by default. Go to Preferences > Code Recommenders > Completions and activate the Subwords-Completion Processor.