Symlink for Currently Selected Alert Sound?

Solution 1:

Workaround

Seems there are no schemas for setting the alert sound options those are available via GUI

Observations:

Sound theme can be set with gsettings

gsettings set org.gnome.desktop.sound theme-name 'mySoundTheme'

to see the current theme.. run gsettings get org.gnome.desktop.sound theme-name

Example:

$ gsettings get org.gnome.desktop.sound theme-name
'ubuntu'
$ 

when Bark is selected from the GUI, It uses same ubuntu theme but instead of the file /usr/share/sounds/ubuntu/stereo/bell.oga it uses /usr/share/sounds/gnome/default/alerts/bark.ogg

when Drip is selected it uses drip.ogg, in the same way for Glass and Sonar also.

In all the above 4 Selections, the system sound theme is constant which is ubuntu which is used by the Thunderbird.

When the option "Default system sound for new mail" is selected in Thunderbird it uses message.ogg file for new mails and bell.ogg file for alerts from the custom theme

Note that the names in some custom downloaded themes may vary for message.ogg and bell.ogg etc..

So the idea is to create 4 Custom Sound Themes with name bark, drip, glass & sonar..

to do so, just copy ubuntu directory and rename it with above names..

replace the files message.ogg and bell.ogg with the sounds you wish in all the four directories bark, drip, glass & sonar..

now you can choose the custom theme you want with gsettings command or via dconf-editor tool which can be installed with sudo apt install dconf-editor

gsettings set org.gnome.desktop.sound theme-name 'bark'
gsettings set org.gnome.desktop.sound theme-name 'drip'
gsettings set org.gnome.desktop.sound theme-name 'glass'
gsettings set org.gnome.desktop.sound theme-name 'sonar'

If you want to reset, run below command

gsettings reset org.gnome.desktop.sound theme-name

to remove the options from GUI for any accidental selection of "Choose an alert sound"

rename the file /usr/share/gnome-control-center/sounds/gnome-sounds-default.xml to anything you wish..

Tested in Ubuntu 18.04.2, Worked as intended.