RFE: Add "Also apply changes to login screen" to some options of the Preferences dialog

[Francesco Fumanti]

In message #4 of the bug thread indicated by the following link, Mark Bokil considers an inconsistancy the fact, that the theme changes the he does for Onboard in the desktop session do not also apply to the login screen.
https://bugs.launchpad.net/ubuntu/+source/unity-greeter/+bug/973922

Regardless of it being an inconsistancy or not, the problem that it is not possible to open the Preferences dialog of Onboard while it is running at the login screen might be relieved, if it was possible to change some settings of Onboard from within the desktop session. Thus my idea to add an "Also apply changes to login screen" option for the theme settings (as asked by mark), the layout settings and maybe the transparency settings settings of the Preferences dialog of Onboard. (

I suppose that making the macro definitions of the desktop session available under the login screen would not make much sense, especially not if it is running on a computer used by more than one person.

Finally, I am aware that copying some changes done to the Preferences of Onboard to the login screen will require root privileges. I suppose that the higher privileges can be achieved by using the policykit and this will at the same time make sure that the changes to Onboard at the login screen can be done only by system administrators.

[Mark Bokil (mark-bokil)]

There already is a way to change the theme at the desktop level for the onboard keyboard. From the panel indicator you can select preferences and then theme. This sets the desktop onboard theme and also the onboad which appears at screen lockout. The greeter is the only onboard keyboard which has the default theme statically set. On my 12.10 system there are 3 places where the onboard keyboard appears: 1) greeter. 2) desktop invocation by launcher, indicator, shortcut, etc. 3) screen lockout with onboard at bottom of password screen. I am guessing you can read the existing gschema setting for onboard at greeter screen and apply it. So maybe ability to set onboard at greeter is not needed.

[marmuta (marmuta)]

From Onboard's point of view running in lightdm is little different from running in any user session. Preferences are already read from gsettings as usual. For example, you can change the theme in the login window with
sudo -u lightdm dbus-launch gsettings set apps.onboard theme Droid
or for Onboard trunk
sudo -u lightdm dbus-launch gsettings set org.onboard theme Droid
for example.
It's really only the GUI that's missing. The preferences Dialog doesn't cut it for security reasons and because unity-greeter has no real window manager.

Mark, if Onboard in lightdm tried to read preferences from a different user, we had the problem to decide from which one. There may be multiple users set up on the system, each with different settings for Onboard.

Francesco's suggestion has the advantage that it's clear whose preferences are to be copied. So, I tend to think having some "apply to login screen" button isn't a bad idea. We would need to copy more than gsettings values though, as there might be user modified/created themes in the home directory.

Some alternatives that came to mind:
- Provide a simplified GUI in lightdm, just a list of system themes to chose from.
- In the user session, provide a way to launch the whole preferences dialog as user lightdm.

However, customized themes can't be easily synchronized with these.

[Francesco Fumanti (frafu)]

@marmuta

> sudo -u lightdm dbus-launch gsettings set apps.onboard theme Droid
> or for Onboard trunk
> sudo -u lightdm dbus-launch gsettings set org.onboard theme Droid

Yesterday, I had the intention to write about these commands above; but they do not seem to work anymore. However, their counter part to read the keys (sudo -u lightdm dbus-launch gsettings get org.onboard theme) are still working.

A little research with google confirmed the problem writing gsettings keys, and there were indications about other approaches like switching to the lightdm user or like using xhost...

> Mark, if Onboard in lightdm tried to read preferences from a different
> user, we had the problem to decide from which one. There may be multiple
> users set up on the system, each with different settings for Onboard.
>
> Francesco's suggestion has the advantage that it's clear whose
> preferences are to be copied. So, I tend to think having some "apply to
> login screen" button isn't a bad idea. We would need to copy more than
> gsettings values though, as there might be user modified/created themes
> in the home directory.

An idea would be to add a copy of the custom files of the user into a subfolder with the user's name; this subfolder could be located in the same folder where Onboard stores the layout or theme files it is shipping. The main idea here is to create a folder with the user's login name in order to be able to tell whom the custom files belong to.

> Some alternatives that came to mind:
> - Provide a simplified GUI in lightdm, just a list of system themes to chose from.

And who would be allowed to change settings? Everybody?

By doing it from the desktop session, it would be automatically restricted to users with the ability to require root privileges (in other words to administrators), as root privileges will be required to do things as the lightdm user. (What about gdm, kdm,.. ?)

> - In the user session, provide a way to launch the whole preferences dialog as user lightdm.

There are quite a few settings that do not make sense under the display manager (application indicator, show on every workspace, resize protection,.. I don't think this to be a good idea unless there is a way for the user to tell what settings do make sense under the display manager. Considering this, I suppose that adding the "Also apply to login screen" is a simpler approach.

[George Thomas (georgefsthomas)]

For now, this can be worked around, for LightDM at least: use a custom theme with all of your settings, and copy it from `~/.local/share/onboard/themes` to `/usr/share/onboard/themes/`, and point LightDM to the theme by specifying the `-t` flag to Onboard. It seems that LightDM doesn't have permission to read from the user's home directory (I'm guessing - I can't actually find any relevant logs).

Of course, this only works for settings which are part of the theme, which annoyingly doesn't include transparency.