Could you please check if it happens after 7349? Thank you

Anna, problem is still present in 7.0 (#7361).

Example code I used to reproduce the issue:

public class TarasTest {
    public static void main(String[] args) {
        final ArrayList<String> arrayList = new ArrayList<String>();
        arrayList.add("Hello");
        String[] strings = arrayList.toArray(new String[0]);
    }
}

The popup spanning the whole screen seems only to happen when Project View is open.

Attached files "screenshot-2.jpg" and "screenshot-3.jpg", obtained using #7361.

I've seen such a tooltip containing scrollbars, however it's been impossible to reach them because the tooltip vanished when moving the mouse ;)

Sascha, that particular annoyance (but for normal-sized popups) is also mentioned in IDEA-41374.