Disabling Eclipse autocomplete but keeping autoactivation

The checkbox you have to check is: "Disable insertion triggers exept 'Enter' "

(under Java -> Editor -> Content assist)

I'm on Eclipse 2018-12 and C_H's answer had no effect on the behavior:

I believe what you'll want is to deactivate "Insert single proposals automatically"

EDIT: It seems this answer is now outdated. It may work for old Eclipse versions. For any more recent versions refer to @ChrisP's answer from 2019.

Open menu Window, then Preferences. Follow path Java -> Editor -> Content assist. Now mess around with the settings to find your ideal setup. I believe what you'll want is to deactivate "Insert single proposals automatically".

If anyone wants to know how to stop the auto-complete for brackets:

Toggle off: "Edit --> Smart Insert Mode"

Version: Eclipse Photon