Ubuntu – How to set the own (HTML) theme in LightDM

11.10lightdmthemes

LightDM is the new login manager, and is meant to be themeable using HTML and CSS. How do I do that in Ubuntu 11.10? Can I use my own HTML file with my own text?

Things I've tried:

  • I've spent a little while googling about and found nothing very useful so far, apart from how to change the background image.
  • There is a launchpad answer referencing a theme directory but no clue as to what should go in the theme directory. It appears there used to be a /usr/share/lightdm/themes directory, but it is not on my system.
  • I've spent a while looking but haven't found the files the current theme is in – if I could find that I could try copying and adapt it – I've done dpkg -L of both the lightdm and unity-greeter packages but not seen any HTML or CSS files.
  • I have found the LightDM Reference Manual but that appears to be an API reference, not a configuration guide.
  • I have tried browsing the LightDM code but can't find any sample HTML/CSS files.

Edit: To clarify I'd like to be able to edit an HTML file so I can add text to the login screen, not just change the fonts and background image. Sorry to @jokerdino who answered an unclear question.

Edit 2: Found a few more clues, but will have to play with them later.

  • I have found /usr/share/lightdm-gtk-greeter/greeter.ui which is part of the lightdm-gtk-greeter package. It is an XML file that looks a bit like the login screen, but I'm not familiar with how to edit that.
  • I have also found this sample HTML file which I can look at the source of (provided I don't let it time out – 5 seconds). It's linked to this javascript file which fakes lightdm for the web mockup. So maybe I can try putting a modified version of the HTML file in a directory and call that the theme directory … But will have to try later – unless someone writes up some working instructions before then – hint, hint.

Best Answer

Caution: Do not try this if you are not completely comfortable booting without X to repair lightdm configuration.

The package lightdm-webkit-greeter is not included in the ubuntu repository yet. To build your own greeter with HTML, CSS and Javascript, you'll have to download and install the lightdm-webkit-greeter code from Launchpad (lp:lightdm-webkit-greeter). I also merged in the changes in lp:~elementaryart/lightdm-webkit-greeter/fixes-ubuntu-old

You'll then have to alter the Lightdm configuration to use the webkit greeter as opposed to unity (or whatever was default).

I believe there is a bug in the lightdm-webkit-greeter.conf file, where it refers to a webkit-theme called "default", that should be "webkit".

I currently use the webkit greeter to log in and can tell you that it is slow and unpolished at the moment.

Step by step:

(be prepared to fix the greeter configuration without a GUI if this fails)

  1. bzr branch lp:lightdm-webkit-greeter
  2. cd lightdm-webkit-greeter
  3. bzr merge lp:~elementaryart/lightdm-webkit-greeter/fixes-ubuntu-old
  4. ./autogen.sh (you'll have to install some dependencies here - probably only libwebkit-dev)
  5. make
  6. sudo make install
  7. gksudo gedit /etc/lightdm/lightdm.conf
  8. Set greeter-session=lightdm-webkit-greeter (remember the old setting as a fallback if you can't log in with your new settings)
  9. gksudo gedit /etc/lightdm/lightdm-webkit-greeter.conf
  10. Set the webkit-theme=webkit

This should work to enable the default webkit login. Now you can edit the theme here:

gksudo gedit /usr/share/lightdm-webkit/themes/webkit/index.html

Edit: Another warning - you can seemingly lock yourself out of gnome if this does not work.

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