Gnome-shell: Quick language Switch extension

Gnome shell extension to quickly switch keyboard language layout, without waiting for the switcher popup to appear.

TIP: to facilitate typing while switching language, assign the "Switch to next/previous input source" keyboard shortcut to a single keystroke, like then [SysRq/Print] key.

Install

Install it from Gnome-extensions site, or directly from GitHub with this command:

git clone https://github.com/ankostis/gnome-shell-quick-lang-switch ~/.local/share/gnome-shell/extensions/[email protected]

and then ensure it is enabled:

gnome-extensions info [email protected]
gnome-extensions enable [email protected]

If the 1st command above reports that extension does not exist, logout and re-login (required for Wayland).

Rational

The language switcher popup by defaulttakes ~0.7sec to appear, meaning that roughly 2-4 strokes are lost till the switch completes. This affects heavily users typing languages with non-latin based alphabets (e.g. Greek, Cyrilic, Arabic, Japanese), particularly when writting technical documents.

Acording to the recipes below, to safely workaround this issue both on X and Wayland you could employe a "custom keyboard shortcut" to delegate to a bash-script performing the switch through dbus, which bypasses the popup:

• https://askubuntu.com/questions/972926/how-to-not-show-keyboard-layout-chooser-popup-when-changing-language-in-gnome-3
• https://itectec.com/unixlinux/how-to-change-keyboard-layout-in-gnome-3-from-command-line/
• https://unix.stackexchange.com/a/449475/156357
• https://askubuntu.com/a/1136485/251379

Unfortunately, due to security concerns, dbus can no longer call method org.gnome.Shell.Eval with arbitrary code, since Gnome-shell v41 (e.g. pushed downstream to Debian unstable "SID" roughly on Sept 2021).

Improvements

A better solution would be to modify the original ui/status/keyboard.js code to skip the switcher-popup based on some new boolen preference (e.g. settable from Tweaks ), as requested by gnome-shell#2945 issue.

Changes

Version-1: re-bind switch-input-source shortcut to direct switch

It re-binds the 'switch-input-source' shortcut:

• when enabled, the shortcut delegates to the direct-switching method InputSourceManager._modifiersSwitcher, and
• when disabled, it the shortcut is restored to the original InputSourceManager._switchInputSource method. Note, it won't reset it to any previous monkeypatches.