lxqt-session - make WM selection smarter

[shirishag75]

For some unknown reason, when I entered for a lxqt session, lxqt asked me for the default window manager

There is/was no way to take the screenshot unless was in a VM hence reused the picture shared on the forum.

now if you look at the dialog box it doesn't give you any hint how do you get out of the session to come to the default login screen and the user is sort of stuck there.

I was able to use CTRL+ALT+Fn to come to a terminal emulator, shutdown lightdm via systemctl and restart lightdm to get the login screen, go to mate-desktop, look up https://forum.lxqt.org/t/selecting-default-window-manager-in-lxqt-0-13-0/309 and use the settings shared by agaida at https://forum.lxqt.org/t/selecting-default-window-manager-in-lxqt-0-13-0/309/7 , copy the needful to /etc/xdg/lxqt/session.conf and was able to login.

A user shouldn't need to go through such loopholes.

FWIW, there is/was no file named session.conf in /etc/xdg/lxqt/

Update - I removed session.conf in /etc/xdg/lxqt/ and tried logging in again and this time it worked, dunno the reason why it worked this time but not the other time.

System credentials in case they throw any more light -

Package: lxqt-session
Version: 0.13.1~181-gab84e77-3
Severity: normal

-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'unstable'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.18.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_IN, LC_CTYPE=en_IN (charmap=UTF-8), LANGUAGE=en_IN:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages lxqt-session depends on:
ii  libc6                     2.27-6
ii  libkf5windowsystem5       5.49.0-1
ii  liblxqt0                  0.13.0-1
ii  libqt5core5a              5.11.1+dfsg-9
ii  libqt5dbus5               5.11.1+dfsg-9
ii  libqt5gui5                5.11.1+dfsg-9
ii  libqt5widgets5            5.11.1+dfsg-9
ii  libqt5x11extras5          5.11.1-2
ii  libqt5xdg3                3.2.1~11-g374f418-1
ii  libstdc++6                8.2.0-7
ii  libudev1                  239-10
ii  libx11-6                  2:1.6.7-1
ii  lxqt-qtplugin             0.13.0-2+b1
ii  lxqt-themes [lxqt-theme]  0.13.0-1
ii  x11-xkb-utils             7.7+4

Versions of packages lxqt-session recommends:
ii  lxqt-config           0.13.1~502-gfd3b8c7-4
ii  lxqt-notificationd    0.13.1~90-g41123bd-1
ii  lxqt-policykit        0.13.1~50-g5c1a745-1
ii  lxqt-powermanagement  0.13.1~137-gea33bfa-1
ii  lxqt-session-l10n     0.13.1~181-gab84e77-3
ii  lxqt-sudo             0.13.1~78-ga571dda-1
ii  pcmanfm-qt            0.13.0-2
ii  qlipper               1:5.1.2~13-g0e90641-1
ii  qps                   1.10.19~84-g38c3fe1-1
ii  xscreensaver          5.40-1

lxqt-session suggests no packages.

-- no debconf information

[tsujan]

A user shouldn't need to go through such loopholes.

I agree completely.

@agaida Is it fixed in the latest git?

This isn't the first time that message box is shown in a report. I don't remember how the other reports were closed but, IMO, a user should never encounter it. Starting without any window manager is much better than showing this message and, if there is a WM installed on the user's system, it should be selected automatically.

I hope this has become totally impossible with the latest git; otherwise, it'll be a release blocker.

[palinek]

This window is shown, if currently configured WM is not found:

    // If previuos WM was removed, we show dialog.
    if (mWindowManager.isEmpty() || ! findProgram(mWindowManager.split(QL1C(' '))[0]))
    {
        mWindowManager = showWmSelectDialog();
        settings->setValue(QL1S("window_manager"), mWindowManager);
        settings->sync();
    }

The list of known window managers is taken from {XDG}/lxqt/windowmanagers.conf:

WindowManagerList getWindowManagerList(bool onlyAvailable)
{   
    LXQt::Settings cfg(QSL("windowmanagers"));
    cfg.beginGroup(QSL("KnownManagers"));
    const QStringList names = cfg.childGroups();
    
    WindowManagerList ret;

    for (const QString &name : names)
    {
        bool exists = findProgram(name);
        if (!onlyAvailable || exists)
        {   
            cfg.beginGroup(name);
            WindowManager wm;
            wm.command = name;
            wm.name = cfg.localizedValue(QSL("Name"), wm.command).toString();
            wm.comment = cfg.localizedValue(QSL("Comment")).toString();
            wm.exists = exists;
            ret << wm;
            cfg.endGroup();
        }
    }

    return ret;
}

The default windowmanagers.conf config is here.

... and I agree that the dialog should have a "Leave session" button

[tsujan]

Apparently, it should never happen. Why has it been reported several times? This time, from Debian!

[palinek]

Apparently, it should never happen. Why has it been reported several times?

IMO when the user removes all "known" window managers w/o setting some existing into lxqt-config-session

[palinek]

Or there is a problem in the logic for checking if the window manager (its executable) is present...

[shirishag75]

I have two desktops installed, one is debian-mate and the other debian-lxqt . The other thing I did find is that xfwm does not seem to be a dependency of anything if it's the default window manager. It should be at the very least be a dependency of task-lxqt-desktop or something more appropriate.

$ aptitude show task-lxqt-desktop
Package: task-lxqt-desktop
Version: 3.46
State: installed
Automatically installed: no
Priority: optional
Section: tasks
Maintainer: Debian Install System Team debian-boot@lists.debian.org
Architecture: all
Uncompressed Size: 6,144
Depends: tasksel (= 3.46), task-desktop, sddm, sddm-theme-debian-elarun | sddm-theme-debian-elarun, lxqt
Recommends: xsane, orca, libreoffice-gtk3, synaptic, libreoffice, libreoffice-help-en-us, mythes-en-us, hunspell-en-us, hyphen-en-us, system-config-printer
Description: LXQt
This task package is used to install the Debian desktop, featuring the LXQt desktop environment, and with other packages that Debian users expect to have available on the desktop.

The more perplexing question to me is why it couldn't find lightdm ? Perhaps because it's GTK2 based ?

The problem with this choice is it allows you to traverse through directories and folders if you click on other but most users would be clueless as to what to do.

[palinek]

Can anyone, please, test the "abort" functionality with #181?

[palinek]

The other thing I did find is that xfwm does not seem to be a dependency of anything.

How is that? I see it:

Package: task-lxqt-desktop
Depends: tasksel (= 3.46), task-desktop, sddm, sddm-theme-debian-elarun | sddm-theme-debian-elarun, lxqt

Package: lxqt
Depends: featherpad, lximage-qt, lxqt-core (= 27), lxqt-about, lxqt-admin, lxqt-openssh-askpass, lxqt-powermanagement, lxqt-sudo, pavucontrol-qt | pavucontrol, qlipper | clipit | xfce4-clipman, qps, qterminal, qttranslations5-l10n, sddm-theme-debian-maui | sddm-theme | lightdm | gdm3 | lxdm | slim | nodm, xarchiver | ark | engrampa, xfwm4 | x-window-manager
Recommends: audacious | clementine | qmmp, calibre, cmst | nm-tray | network-manager-gnome | plasma-nm | wicd, smplayer, smtube, quassel | quassel-client | hexchat | irssi | weechat, qpdfview, gucharmap, firefox | www-browser, thunderbird | claws-mail | mutt

[agaida]

will have a look later - and @palinek, you are right lxqt depend on xfwm4|x-window-manager means that there must be a window manager installed, with xfwm4 as default alternative. That also means that xfwm4 will not be installed when a different WM is installed. The delivered configuration defaults to xfwm4 - so one has to chose the WM - we need a windows manager, so an abort don't make any sense at this point.

Second notice: This is not an upstream problem. So we can close this here.

Edit: We should check the WM list - but thats a different problem.

[tsujan]

Second notice: This is not an upstream problem. So we can close this here.

I may be very ignorant in this case and what I'm going to say may sound irrational: It should not happen at all when there is a WM that works with LXQt.

[tsujan]

I mean, whether the user has chosen a WM or has left it blank, LXQt should behave more intelligently.

[palinek]

It should not happen at all when there is a WM that works with LXQt.

It wouldn't happen if all WMs that work with LXQt would be listed in windowmanagers.conf ...

[tsujan]

If you mean /usr/share/lxqt/windowmanagers.conf, that's acceptable. Then why aren't they listed there for some users? Wrong compilation/package building? If @shirishag75 didn't use Debian, I'd say it was Ubuntu's fault. @agaida Do bad packages exist in Debian?

[tsujan]

Here, /usr/share/lxqt/windowmanagers.conf is:

[KnownManagers]
openbox/Name=Openbox
openbox/Comment=Light-weight window manager

kwin/Name=KWin
kwin/Comment=Window manager of the KDE Software Compilation

kwin_x11/Name=KWin
kwin_x11/Comment=Window manager of the KDE Software Compilation

metacity/Name=Metacity
metacity/Comment=Window manager of the GNOME desktop environment

windowmaker/Name=Windowmaker
windowmaker/Comment=A classical lightweight window manager

e16/Name=Enlightenement 16

fvwm2/Name=Fvwm2
fvwm2/Comment=A classical lightweight window manager

xfwm4/Name=Xfwm4
xfwm4/Comment=A window manager for the Xfce desktop environment

sawfish/Name=Sawfish
sawfish/Comment="A lightweight, flexible window manager"

And ~/.config/lxqt/windowmanagers.conf is:

[General]
__userfile__=true

[agaida]

The issue is with the default settings - given that we deliver in debian with preconfigured xfwm4 - so if xfwm4 isn't installed the session management has to ask which WM to use. So possible WMs should be listed in the dialogue, we should test this. But an abort button will not help in this case we just need a WM :) - behave more intelligent would be a solution - if at least one WM from the list is found: Use that - if more than one WM is found and the WMs found are not the current config - display the dialogue.

Best outcome would be: We don't deliver any pre-configuration and if only one WM is installed we take this installed and recognized WM as default.