On Ubuntu 18.04 (GNOME Shell 3.28.1) I also noticed lags when switching layouts through Alt+Shift
. At 16.04 this was not.
I noticed that if I use the standard Super+Space
combination, it works faster.
I found this solution: https://askubuntu.com/a/986629/766670
The bottom line is that Alt+Shift
is an add-on combination of switching (slow), but the standard - fast.
Therefore, you can replace the key combination of the standard method with the desired one and switching will work faster:
gsettings set org.gnome.desktop.wm.keybindings switch-input-source "['<Alt>Shift_L']"
gsettings set org.gnome.desktop.wm.keybindings switch-input-source-backward "['<Shift>Alt_L']"
I hope this helps someone to avoid wasting time on finding a solution.