How to see grails documentation on mouse hover?

I am very new to Grails I want to get info about each function just hovering the mouse as I did in java/android via Windows->Preferences->Java->Editor->hover.

I am using Groovy/Grails Tool Suite Version: 3.6.4.RELEASE

Solution

From what I can gather playing with settings on my local GGTS 3.6.3, the same settings location that you've given:

Windows -> Preferences -> Java -> Editor -> Hover

Appear to apply to my .groovy files as well. I have the following enabled:

Combined Hover - with Pressed key modifier while hovering left blank
Externalized String
Javadoc
Source