I want to use the onboard keyboard to enter text into a form in a website I have open in firefox. Ideally I want to run firefox in fullscreen mode. In non-fullscreen mode onboard comes up no problem, but when I enter fullscreen onboard disappears, and doesn't show until I leave fullscreen mode again. I have tried the obvious things such as while in fullscreen clicking the hovering onboard icon, and having onboard automatically appearing when highlighting a text input. In both cases it seems onboard does start, except it again does not actually show up untill I leave fullscreen.
I assume that fullscreen mode means you enter some different sort of 'display session', to which onboard has no access. I observed the same behaviour when using chromium instead of firefox, so I guess this is less related to firefox, and more to the OS display manager. I am running lightdm by the way, in a gnome 3 session (not using unity).
So I'm wondering what is actually happening when entering fullscreen mode, i.e. why does onboard disappear? And is there any way of making onboard show in fullscreen mode?