I'm not saying this functionality of Eclipse does not work. It does. When I move the cursor over some local func, a pop-up window shows the definition.
However, I don't know how, this pop-up window is shown with a black background and black character font. You know how it becomes...I cannot see anything! It has been like this since it firstly gets installed. I'm using Ubuntu 8.04 and Eclipse3.5.2 with CDT. I cannot update to Ubuntu11.10. This is another story anyway.
Just wonder where I can specify the color scheme? Guess there should be something in preference to customize that.