I am having an issue where my Ubuntu 18.04 OS keyboard shortcuts are interfering with my PHP Storm ones. I was reading Unable to use IntelliJ IDEA keyboard shortcuts on Ubuntu and was looking for "Switch to workspace" action which had CTRL + ALT + ARROW KEYS, but I don't see those keys listed as a shortcut at all. I am using a fresh copy of Ubuntu (after my old one needed to be rebuilt) and I know that I was able to find it in the past.
The option to change the shortcut keys to switch workspace up, down, left or right (the latter not applicable in default gnome shell) indeed are not exposed in that dialog. You still can change these keyboard assignments by installing
dconf-editor. Navigate to
org.gnome.desktop.wm.keybindings to find all these window manager related keybindings. You will be able to remove all
<Control><Alt><Arrow key> combinations there, leaving alternative keybindings, i.e.,
<Super>Page_Up in place.
Using the terminal
Settings can also be changed using the terminal. For example, to list all available keys, issue the command
gsettings list-keys org.gnome.desktop.wm.keybindings
To learn about what a key contains:
gsettings get org.gnome.desktop.wm.keybindings switch-to-workspace-down
(Tip: Tab-completion works to complete the names of the schema's and keys)
<Control><Alt><Down>, redefine the key:
gsettings set org.gnome.desktop.wm.keybindings switch-to-workspace-down ['<Super>Page_Down']
To reset to default:
gsettings reset org.gnome.desktop.wm.keybindings switch-to-workspace-down