Under Microsoft Windows 8, our Sony VAIO Tap 20 (a touch-screen desktop computer) automatically displays an on-screen keyboard if one touches a text field on-screen or there is otherwise no keyboard available (for example, the included bluetooth keyboard is switched-off or flat)... There is also a (notification area/system tray-based) option to display or hide the on-screen keyboard on-demand.
Does such functionality exist under Ubuntu 14.04 LTS ("Trusty Tahr")?
My understanding is that Ubuntu 14.04 LTS ("Trusty Tahr") is supposed to be a mostly smartphone/tablet-focused upgrade... But for the life of me, I cannot find functionality that replicates that of Windows 8 (as described above)!
I've finally convinced the wife to let me single-boot Ubuntu on our VAIO Tap 20, but the included bluetooth keyboard smashes through batteries like they're going out of fashion, so until we can buy a corded keyboard, we need a solution (preferably built-in) that replicates the functionality found under Windows 8...
Never mind - all one needs to do after @Rmano 's solution is log-out and log back in... I should also note that this was already installed under Ubuntu 14.04 LTS ("Trusty Tahr").