Bug 30472 - Using picom as compositor/WM on LxQt, window title bars do not appear making it impossible to close windows. Also does not remove dependency when uninstalled
Summary: Using picom as compositor/WM on LxQt, window title bars do not appear making ...
Status: NEW
Alias: None
Product: Mageia
Classification: Unclassified
Component: RPM Packages (show other bugs)
Version: 8
Hardware: All Linux
Priority: Normal normal
Target Milestone: ---
Assignee: Florian Hubold
QA Contact:
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-05-25 17:18 CEST by Edward
Modified: 2023-05-07 14:48 CEST (History)
2 users (show)

See Also:
Source RPM: picom-8.2-3.mga8.x86_64.rpm, libev
CVE:
Status comment:


Attachments
Screenshot of Chromium screen without window title bars or info in LXQt panel (211.33 KB, image/png)
2022-05-25 20:45 CEST, Edward
Details
Screenshot of Firefox screen without window title bars or info in LXQt panel (87.22 KB, image/png)
2022-05-25 20:46 CEST, Edward
Details

Description Edward 2022-05-25 17:18:06 CEST
Description of problem:

Installed picom to try to eliminate screen tearing (video is integrated AMD Radeon 3000, using the 'ati' driver per xorg.conf).

Found it to be extremely slow, but it caused the window title bars to not appear, making it impossible to close windows. Desktop is LXQt.

In addition, upon installation of picom, it also wanted to install lib64ev4 as a dependency, but when uninstalling picom using 'urpme picom', it did not uninstall this dependency with it. Running 'urpme --auto-orphans' indicated there were no orphaned packages, so lib64ev4 was uninstalled using 'urpme lib64ev4'.

Version-Release number of selected component (if applicable):

picom-8.2-3.mga8.x86_64.rpm

I uninstalled it because it was too slow and switched it back to the default openbox, but wanted to report this as a bug, in case the window title bars should have appeared when using picom as a compositor.
Comment 1 Morgan Leijström 2022-05-25 19:43:20 CEST
For starter: Do the information in our errata help?
https://wiki.mageia.org/en/Mageia_8_Errata#LXQt

CC: (none) => fri

Comment 2 Edward 2022-05-25 20:44:07 CEST
(In reply to Morgan Leijström from comment #1)
> For starter: Do the information in our errata help?
> https://wiki.mageia.org/en/Mageia_8_Errata#LXQt

I had no issues with the translucency, it's just that using picom as the compositor caused anything video-related to slow down, in addition to the lack of window title bars. By default, with picom, the transparency was what I was looking for, so I did not need to change any config files, but picom was simply too slow for the system.

I then installed xfwm4 (which is the default window manager for LXQt on other Linux distros I've used previously) and am not having any issues with that. I was able to make the LXQt panel translucent, but it otherwise does not make the menus translucent like picom does. Using xfwm4 as the window manager, also appears to have resolved the screen tearing issue for me.

I am attaching screenshots of Chromium and Firefox, displaying the lack of window title bars using picom, as well as the lack of the window information in the LXQt panel, as a result.
Comment 3 Edward 2022-05-25 20:45:50 CEST
Created attachment 13273 [details]
Screenshot of Chromium screen without window title bars or info in LXQt panel
Comment 4 Edward 2022-05-25 20:46:31 CEST
Created attachment 13274 [details]
Screenshot of Firefox screen without window title bars or info in LXQt panel
Comment 5 Morgan Leijström 2022-05-25 20:54:09 CEST
Thank you Edward for the report.

CC the registered maintainer of LXQt for comment.

CC: (none) => doktor5000

Comment 6 Edward 2022-05-25 21:04:07 CEST
One small correction to make. xfwm4 *does* in fact, make the LXQt menus translucent. It was not noticeable at first, because of the desktop wallpaper. Once I changed it back to the default Mageia wallpaper, I was then able to see the translucency.
Comment 7 Lewis Smith 2022-05-26 21:54:26 CEST
CC'ing also daviddavid who is the registered maintainer for 'picom', but not sure if he is still active.

> xfwm4 (which is the default window manager for LXQt on other Linux distros
> I've used previously)
This is interesting, because you seem to be very happy with it: "am not having any issues with that", "Using xfwm4 as the window manager, also appears to have resolved the screen tearing issue for me".
Maybe we should do likewise.

 As for picom itself, it looks a bit chancy:
Picom is a lightweight compositor for X11 (previously a compton fork).
The current battle plan of this fork is to refactor it to make the code
possible to maintain, so potential contributors won't be scared away when they
take a look at the code.
We also try to fix bugs.

CC: (none) => geiger.david68210, lewyssmith

Comment 8 Edward 2022-05-26 23:04:01 CEST
I can't recall which distros I tried that used xfwm4 as default, it might only have been a couple of them. But *most* distros I've used, like Mageia, use openbox as the default. I understand openbox is no longer maintained upstream. I noticed in the pull-down list, icewm was also listed which came with the original Mageia installation, but I have never tried icewm.

I have noticed a few things in using xfwm4:

After changing the window manager from openbox to xfwm4, I powered down. Upon logging in after a cold boot, the display will show yellow and amber bars going horizontally across the screen for a few seconds, until the LXQt desktop appears. This occurs on both of my systems. One has an integrated AMD/ATI Radeon 3000 and the other has an AMD Radeon HD 5450 PCI Express x16 video card. The yellow and amber bars on the HD 5450 display are wider than what is displayed with the 3000. I am curious as to whether this also occurs with non-Radeon GPU's, such as NVIDIA.

What would be called the Openbox Theme, automatically changed to Oxygen under xfwm4. This was discovered selected in the Openbox Configuration Manager, even though it's not using Openbox now and this theme cannot be changed. There is a package xfwm4-themes (no dependencies were listed), however once installed, there was no GUI available to change the theme. If there is a GUI for it, it may be specific to the XFCE desktop.

Making the LXQt panel transparent or translucent, will take some tweaking with some of the LXQt themes. The Dark theme, as is, required no tweaking, the LXQt menus and the panel became translucent on its own. And the visibility of the translucency is dependent on the background (desktop wallpaper, web page background, etc.)

I hope this information is helpful.
Comment 9 Edward 2022-05-27 18:18:52 CEST
This is the integrated Radeon 3000. Apparently it's using 'radeon', not 'ati' per my original description.

01:05.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] RS780L [Radeon 3000] [1002:9616]
        Subsystem: Hewlett-Packard Company Device [103c:2ab7]
        Kernel driver in use: radeon
        Kernel modules: radeon
Comment 10 Lewis Smith 2022-05-27 22:12:53 CEST
Thank you for your further comments.
> After changing the window manager from openbox to xfwm4
> the display will show yellow and amber bars going horizontally across
> the screen for a few seconds, until the LXQt desktop appears
You do not say, but this implies after logging in.
This corresponds to a permanent glitch we have when launching Xfce from any display manager, which displays a similar sort of screen for a couple of seconds before the correct Xfce desktop. I say this because 'xfwm4' is the Xfce window manager, although I am unsure whether it is used as standard with Xfce. I must look into that.

It is useful to post the output of:
 $ inxi -MSGxx
which shows most basic details including window manager and graphics.
Comment 11 Edward 2022-05-28 17:23:11 CEST
Correct. The yellow/amber bars appear after logging in and before the desktop appears.

The below output is from my desktop with the integrated Radeon:

System:
  Host: upstairs Kernel: 5.15.43-desktop-1.mga8 x86_64 bits: 64 compiler: gcc 
  v: 10.3.0 Desktop: LXQt 0.16.1 wm: xfwm4 dm: SDDM Distro: Mageia 8 mga8 
Machine:
  Type: Desktop System: Hewlett-Packard product: CQ5826 v: N/A 
  serial: <superuser required> Chassis: type: 3 serial: <superuser required> 
  Mobo: FOXCONN model: 2AB7 v: 1.00 serial: <superuser required> 
  BIOS: American Megatrends v: 6.09 date: 05/04/2011 
Graphics:
  Device-1: AMD RS780L [Radeon 3000] vendor: Hewlett-Packard driver: radeon 
  v: kernel bus ID: 01:05.0 chip ID: 1002:9616 
  Display: x11 server: Mageia X.org 1.20.14 driver: ati,radeon,v4l 
  resolution: 1920x1080~60Hz s-dpi: 96 
  OpenGL: renderer: AMD RS780 (DRM 2.50.0 / 5.15.43-desktop-1.mga8 LLVM 11.0.1) 
  v: 3.3 Mesa 21.3.8 compat-v: 3.0 direct render: Yes 


I will run the same command on my other desktop and post as a separate comment.
Comment 12 Edward 2022-05-28 17:46:11 CEST
From my other desktop, it has a PCI Express x16 video card installed:

System:
  Host: downstairs Kernel: 5.15.43-desktop-1.mga8 x86_64 bits: 64 
  compiler: gcc v: 10.3.0 Desktop: LXQt 0.16.1 wm: xfwm4 dm: SDDM 
  Distro: Mageia 8 mga8 
Machine:
  Type: Desktop System: Compaq-Presario product: NP185AAR-ABA CQ5110F v: N/A 
  serial: <superuser required> Chassis: Hewlett-Packard type: 3 
  serial: <superuser required> 
  Mobo: PEGATRON model: NARRA5 v: 5.00 serial: <superuser required> 
  BIOS: Phoenix v: 5.49 date: 08/06/2009 
Graphics:
  Device-1: AMD Cedar [Radeon HD 5000/6000/7350/8350 Series] 
  vendor: VISIONTEK driver: radeon v: kernel bus ID: 02:00.0 
  chip ID: 1002:68f9 
  Display: x11 server: Mageia X.org 1.20.14 driver: ati,radeon,v4l 
  resolution: 1920x1080~60Hz s-dpi: 96 
  OpenGL: 
  renderer: AMD CEDAR (DRM 2.50.0 / 5.15.43-desktop-1.mga8 LLVM 11.0.1) 
  v: 3.3 Mesa 21.3.8 compat-v: 3.1 direct render: Yes
Comment 13 Lewis Smith 2022-05-29 20:57:11 CEST
Thank you for your system info.
I have installed picom to see what effect it has with other desktops. Under LXDE, it is not immediately availale to choose from as the window manager! To pursue.
Comment 14 Edward 2022-05-29 23:06:32 CEST
In reviewing my comments, I forgot to mention that with picom as the window manager, between the actual login and the LXQt desktop appearing, the screen was completely grey, which is the same experience I had when using picom and LXQt with other Linux distributions in the past. 

The Wikipedia article for LXQt references openbox as the default window manager.
Comment 15 Lewis Smith 2022-05-30 21:18:43 CEST
I have confirmed that our Xfce seems to use 'xfwm4' as its window manager; so the short-lived screen tearing must come from that.

Re picom itself, I note that it is described as a 'compositor', not a window manager. What it is supposed to do... Changing window managers under different desktops is obscure, and when I could find where to do it, picom was never present in the offered choice. Yet it has its own menu entry, whose effect is nebulous. Under Xfce at least, its control centre 'window manager tweaks' has a Compostor tab with an opacity slider for (among other things) window decorations. Having started picom (I think; it was not in ps output), the slider does indeed alter title bar transparency. But whether this is inherent in xfwm4 I do not know.
I will play under LxQt - if I can find similar window manager/compositer controls.
Comment 16 Edward 2022-05-31 01:28:58 CEST
picom is a compositor.

In LXQt: Preferences/LXQt settings/Session Manager, there is a pull-down list at the top of the LXQt Session Settings window, marked 'Window Manager'. This is where openbox, xfwm4, icewm, picom, etc. is selected, with a Search button to find another window manager that was recently installed, so it can be added to that list. Changes take effect at the next login.

I have always called those offerings a 'window manager', given that this is what the LXQt developers use to describe that feature. :)

The XFCE developers describe xfwm4 as a 'window manager' that includes its own compositing manager. https://docs.xfce.org/xfce/xfwm4/introduction
Comment 17 Lewis Smith 2022-06-01 08:10:06 CEST
Thank you for the instructions, which I had in fact already discovered. I was stumped by the 'search' bit; it seemed enough to simply type 'picom'.

Running under LxQt with it now, and confirm at last the reported problem! The lack of a window title bar also makes Alt/F4 ineffective for closing it. The application close|exit function at least works...

I will try picom under another desktop if possible.
Comment 18 Lewis Smith 2022-06-01 12:17:21 CEST
I could not find how to invoke it from Xfce, LXDE, Plasma, so limiting this to LxQt for now.

As such, assigning to Florian. Please re-assign it more appropriately as you see fit.

DavidG is CC'd for 'picom' & 'lib64ev4' (SRPM libev).
picom has no direct dependancy for lib64ev4, only a recursive one.
Conversely, lib64ev4 has a direct required-by picom.

CC: doktor5000, lewyssmith => (none)
Assignee: bugsquad => doktor5000
Source RPM: picom-8.2-3.mga8.x86_64.rpm => picom-8.2-3.mga8.x86_64.rpm, libev
Summary: Using picom as compositor window title bars do not appear making it impossible to close windows, also does not remove dependency when uninstalled => Using picom as compositor/WM on LxQt, window title bars do not appear making it impossible to close windows. Also does not remove dependency when uninstalled

Comment 19 Edward 2022-06-28 21:48:42 CEST
@Lewis - I posted a message on the Forum with instructions on how to enable the "TearFree" option for the "ati" driver, using older AMD GPU's. This eliminated the screen tearing I previously mentioned, on both of my desktops.

https://forums.mageia.org/en/viewtopic.php?f=23&t=14632

Was curious as to whether the screen tearing may have had anything to do with the yellow/amber bars appearing when xfwm4 is used as the compositor in LXQt and what you also described in Comment 10 re XFCE, to see if perhaps those lines were now eliminated at login, where the "TearFree" option is now enabled in the driver. The lines still appeared at login.
Comment 20 Edward 2022-08-18 20:30:37 CEST
(In reply to Edward from comment #8)
 
> I have noticed a few things in using xfwm4:
> 
> After changing the window manager from openbox to xfwm4, I powered down.
> Upon logging in after a cold boot, the display will show yellow and amber
> bars going horizontally across the screen for a few seconds, until the LXQt
> desktop appears. This occurs on both of my systems. One has an integrated
> AMD/ATI Radeon 3000 and the other has an AMD Radeon HD 5450 PCI Express x16
> video card. The yellow and amber bars on the HD 5450 display are wider than
> what is displayed with the 3000. I am curious as to whether this also occurs
> with non-Radeon GPU's, such as NVIDIA.

I have since installed the Xfce desktop under mga8, which actually uses xfwm4 and am noticing a similar event. After logging in, either the screen turns into amber-colored pixels similar to the previously described, or the mageia logo wallpaper changes from blue to amber in its entirety, then the Xfce desktop appears.

In running Cauldron in a VirtualBox with Xfce, this does not occur.
Comment 21 Edward 2023-05-06 23:49:53 CEST
I have tried other distros with LXQt using Picom and I saw the same issue with those, so this is an upstream issue. 

As for it not removing lib64ev4, I'll let the maintainer close the bug if necessary. 

I am now using Cauldron on a flash drive and although Picom was installed as part of the installation, I am not using it now.

Thank you.
Comment 22 David GEIGER 2023-05-07 14:48:27 CEST
OnCauldron I get:

$ urpmq --requires picom |grep libev
libev.so.4()(64bit)

$ urpmq --whatrequires lib64ev4
i3
i3lock
indilib
latex_of_wiki
lib64ev-devel
lib64shadowsocks2
lib64verto-libev1
lib64websockets-devel
ocaml-lambda-term
ocaml-lwt
picom
python3-gevent
shadowsocks-libev
sniproxy

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