Allow apps to display tray icons in Unity

Only whitelisted apps are allowed to show tray icons in Unity. By default, the apps in the whitelist on my PC are JavaEmbeddedFrame, Mumble, Wine, Skype, hp-systray, and scp-dbus-service.

To show the current whitelisted programs, run

gsettings get com.canonical.Unity.Panel systray-whitelist

To add a new program; for example, Tasque, to the current whitelist, run

gsettings set com.canonical.Unity.Panel systray-whitelist "['JavaEmbeddedFrame', 'Mumble', 'Wine', 'Skype', 'hp-systray', 'scp-dbus-service', 'Tasque']"

Alternatively, we can do this through a GUI using a tool called "dconf-editor". It's part of the "dconf-tools" package. In dconf-editor, go to

desktop -> unity -> panel

and select "systray-whitelist" on the right panel.

After change, strangely doing a relogin didn't seem to take this into effect for me. I had to reboot the PC. I didn't try just killing X Window though.

Refs
http://www.omgubuntu.co.uk/2011/03/how-to-hide-or-show-app-tray-applets-in-ubuntu-11-04/
http://ubuntu.sun.ac.za/wiki/index.php/Show_tray_icons_in_unity