Wednesday, 2 December 2015

Lubuntu/LXDE: cannot add apps to launch-bar

Having installed a fresh image of Lubuntu 15.10, I found I had a problem adding newly installed applications to the Launch Bar.


A quick search of the internet did not reveal anything useful, so I had to open a few files and work out what was happening.


Strange that I hadn't noticed this problem before!

Lubuntu is a light-weight Linux distribution closely related to Ubuntu and Debian. It uses the LXDE desktop environment, which provides a very simple desktop with a customisable panel.

The panel has an application launch area to the right of the "menu" icon, where you can add short-cuts to your most frequently used applicatiions.

apps/icons: menu, File Manager, Firefox, Thunderbird, Remmina, GIMP, gEdit & Gambas


All you have to do is right-click the panel, select "Add/remove panel items", select "Application Launch Bar", and then select "Preferences".



You can then select applications from the list on the right and add them to the launcher bar.

The problem


Previously I was using Lubuntu 15.10 which was just an upgrade, of an upgrade, of an upgrade... And I didn't seem to have any problems adding newly installed applications to my Launch-bar. However, with a fresh install of Lubuntu to a blank ssd, I found that certain applications added via Synaptic did not appear in the Installed Application list (in the illustration above).

The rogue applications included gEdit and Thunderbird, while other newly installed applications like The GIMP were listed and easy to add to the panel.

I opened /usr/share/applications as root (via terminal: gksu pcmanfm) and checked that the desktop files for these applications were in place. Opening a couple of them in a text editor, I noticed the rogue applications contained a line like this:-

OnlyShowIn=Unity;

...so I removed these lines in gedit.desktop and that instantly fixed the problem for gEdit.

In the thunderbird.desktop file I found two lines like this:-

OnlyShowIn=Messaging Menu; Unity;

...so I just removed the "Unity;" bit of this line.

The freedesktop standard


According to the FreeDesktop standard, the "OnlyShowIn" option should specify a "legal" option in an application's .desktop file, otherwise the desktop environment should not include the application in the desktop menu.

This probably implies that either the Lubuntu repository should contain a version of (say) Thunderbird with a LXDE specific thunderbird.desktop file, or applications should configure themselves during installation to suit the desktop environment in use.

3 comments:

  1. Hi Captain!

    I wondered if you could share any further experiences you've had with a fresh installation of Lubuntu 15.10 and make it clear whether you used the 32 or 64 bit version. In my case on a nc4200 notebook I used 32 bit and I'm struggling to find an authoritative guide about adding Samba so the pc can join a Windows Vista Workgroup.

    What I have been "disappointed with" is the dropping in February 2016 by Google of the 32 bit version of Chrome which has it's maintained version of Flash. That took me a few days to track down what happened and find the last version!

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    Replies
    1. Hi Peter, not sure what you require exactly, but I've installed Lubuntu 15.10 64bit on the Asus laptop I'm using right now, and tried to install 32bit version on HP nc6320. This hp laptop has a similar physical look to the nc4200. It will run 15.10, but falls over if I try to use kernel version 4.something. However, this hp laptop runs Mate OK with the latest kernel (very strange).

      Networking; I don't know if you have looked at my networking post (search for "samba" in the "search this blog" feature at the top of the page).

      I don't use Google Chrome. I use Firefox and Midori, and install "flashplugin-installer" via Synaptic or terminal (sudo apt-get install flashplugin-installer).

      I hope this helps.

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  2. Thank you so much for this! Only thing I could find that was similar was outdated (2011). First time using Lubuntu/lxde so I'm still learning the basics. Take care.

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