Java Eclipse make content-assist transparent

First of all, I am new to Java and Eclipse. In Visual Basic they added a feature that allowed you to press the ctrl button in order to temporarily make the content assist transparent. This allowed you to see any code that maybe be covered by the content assist.

My question is simple: is there a way to make the content-assist transparent by pressing a button?

I know that I can turn it off, but I use it too often to turn it off. I just want to be able to see 开发者_JAVA百科the code behind the content assist without having to click somewhere else on the screen to remove the content assist.

From what I can see (after checking the News and Noteworthy of Eclipse 3.6 and even 3.7 or 4.1), this isn't a feature currently supported in Eclipse.
I don't see transparent SWT popup in the current features of SWT.