Wallpaper visible when "lock the screen" is activated

[Jerboum]

I have this problem, that is my wallpaper is still visible when my system is monitor locked.
Is there a fix for this ? Notice that I use the Slideshow mode.
+ I don't understand exactly what means "lock the computer" in the settings, so I don't know what to do with this. I don't want my computer to stop downloading for example, or the motion detection to stop, so will "Lock the computer" do this ?

[spamhog]

big +1 to this question

viewtopic.php?t=399599

SYSTEM SUSPEND - SESSION LOCK - SCREEN SAVER / LOCK / BLANKING / SLEEPING / OFF

I would love to see one page or howto defining all of the above unambiguously.

Usually one gets one or two partial replies. But occasionally one also gets condescendent replies by people who actually do not have superior knowledge, let alone complete knowledge, just the honest impression that they have one or the other.

I don't think anyone is to blame. Its entirely possible that unambiguous definitions do not exist, and that different definitions underlie those terms as used in kernel, X.org, ACPI, Wayland, desktop environments, session managers, and individual GUI applications.

In a GUI I could technically call something "Nirvana" meaning "bringing the computer to ACPI S3 state". IIRC, at one point Thunar (or was it PCmanFM?) had buttons that read "show folder full path" and "show path buttons style" that were just mixed up. Everything worked perfectly but was just mislabeled.

[Jerboum]

I guess that most of the people seeing this subject will think "so don't have a wallpaper... it's simple"
Notice also that the wallpaper in that case is darkened or veiled after a relatively short delay, but in spite of this the wallpaper is relatively clearly visible.
Notice that I used the term "monitor locked" for an action on a button that is called exactly "Lock the screen"

"Delay before starting the screensaver" is set by me to 30' but I didn't really identify this "screensaver" how does it look ? And how does it start, 30' after what ? ?

[Jerboum]

OK, so here is still something that doesn't work on Linux

So I ve just checked some feature on Nemo that is called "Data accessed" and it doesn't work either, it gives a date but not the latest "accessed" date (NTFS)
... to be continued

[billyswong]

Someone wrote a script for this Cinnamon problem.
https://www.preining.info/blog/2020/02/ ... ackground/

located in /usr/local/bin/cinnamon-lockscreen-background.sh

Code: Select all

#!/bin/bash
# 
DESKTOP_BACKGROUND=$(gsettings get org.cinnamon.desktop.background picture-uri)
DESKTOP_SLIDESHOW=$(gsettings get org.cinnamon.desktop.background.slideshow slideshow-enabled)
LOCKSCREEN_BACKGROUND="/path/to/lock/screen/background/image"
# Check for existing instances and kill them leaving current instance running
for PID in $(pidof -o %PPID -x "${0##*/}"); do
    if [ "$PID" != $$ ]; then
        kill -9 "$PID"
    fi 
done
dbus-monitor --session "interface='org.cinnamon.ScreenSaver', member='ActiveChanged'" | while read -r msg
do
  # The profile mode does not contain the actual value of the state, while in
  # normal output mode the state is shown in the second line:
  #signal time=1582609490.461661 sender=:1.17859 -> destination=(null destination) serial=132 path=/org/cinnamon/ScreenSaver; interface=org.cinnamon.ScreenSaver; member=ActiveChanged
  #   boolean true
  #signal time=1582609495.138523 sender=:1.17859 -> destination=(null destination) serial=143 path=/org/cinnamon/ScreenSaver; interface=org.cinnamon.ScreenSaver; member=ActiveChanged
  #   boolean false
  case "$msg" in
    "boolean true")
      DESKTOP_BACKGROUND=$(gsettings get org.cinnamon.desktop.background picture-uri)
      DESKTOP_SLIDESHOW=$(gsettings get org.cinnamon.desktop.background.slideshow slideshow-enabled)
      gsettings set org.cinnamon.desktop.background.slideshow slideshow-enabled false
      gsettings set org.cinnamon.desktop.background picture-uri "file://$LOCKSCREEN_BACKGROUND"
      ;;
    "boolean false")
      gsettings set org.cinnamon.desktop.background picture-uri "$DESKTOP_BACKGROUND"
      gsettings set org.cinnamon.desktop.background.slideshow slideshow-enabled $DESKTOP_SLIDESHOW
      ;;
    *) ;;
  esac
done

autostart item in ~/.config/autostart/

Code: Select all

[Desktop Entry]
Type=Application
Exec=/usr/local/bin/cinnamon-lockscreen-background.sh
X-GNOME-Autostart-enabled=true
NoDisplay=false
Hidden=false
Name=cinnamon-lockscreen-background.desktop
Comment=Change lockscreen background image
X-GNOME-Autostart-Delay=30

Edit the LOCKSCREEN_BACKGROUND line with whatever file path you want.

p.s. In Mate desktop, custom wallpaper after screensaver activated is a built-in feature.

[billyswong]

About what is "lock" in Linux Mint:

Your login session is still active. All your programs are still running. But their access is covered by a fullscreen program that grabbed all your screen space + mouse + keyboard, that is only willing to quit after you give it your correct password.

"Delay before starting the screensaver" is set by me to 30' but I didn't really identify this "screensaver" how does it look ? And how does it start, 30' after what ? ?

The "delay" let people do the following: when one find the monitor fall into sleep / screen going blank / screensaver animation start up, if they move mouse early enough, they can avoid the locking / typing password but get back into active session immediately.

[Jerboum]

About what is "lock" in Linux Mint:

Your login session is still active. All your programs are still running. But their access is covered by a fullscreen program that grabbed all your screen space + mouse + keyboard, that is only willing to quit after you give it your correct password.

"Delay before starting the screensaver" is set by me to 30' but I didn't really identify this "screensaver" how does it look ? And how does it start, 30' after what ? ?

The "delay" let people do the following: when one find the monitor fall into sleep / screen going blank / screensaver animation start up, if they move mouse early enough, they can avoid the locking / typing password but get back into active session immediately.

OK, so I understand it is evident that after locking the screen, I lose all opportunity to see something happen as screensaver starting...

Thanks for your interesting explanations and script

[PaulL]

Think of it this way: locking the computer is for when you want to leave your desk for a few minutes, to get a cup of coffee or whatever. You don't want to shut down your computer, because that's tedious, but you also don't want anyone walking past to be able to mess with your computer or even to see what you are working on. Locking the computer takes care of all that.

Of course, if you trust everyone in your office and don't mind if your boss sees that you like to look at cute kitten videos during working hours, then you never need to lock your computer.

[Jerboum]

Someone wrote a script for this Cinnamon problem.
https://www.preining.info/blog/2020/02/ ... ackground/

I don't understand what meaning this script has.
I read "gives me my preferred background image on both the lock screen and the main desktop"
It is allready what I get and it is the problem I face. I get the background image when I ve locked the screen...

[billyswong]

Do you see within the script the line LOCKSCREEN_BACKGROUND="/path/to/lock/screen/background/image"?

You don't want your usual wallpaper being shown in lockscreen. What the script does is backup your wallpaper setting, then replace them with the path written on that LOCKSCREEN_BACKGROUND line temporarily until you unlock your computer. If you don't know what path to put on, put "/usr/share/backgrounds/linuxmint/default_background.jpg", the default background Linux Mint uses before login.

[Jerboum]

Oh, ok you mean you propose to "hijack" this script by changing the background folder used for the "screen locked" time... perhaps I was too tired yesterday when I worked on that a little...
I can try this, yes


This ?

Code: Select all

LOCKSCREEN_BACKGROUND="/usr/share/backgrounds/linuxmint/default_background.jpg"

And which name to give to the script in autostart ?

[billyswong]

Just use the suggested location/path/filename is okay. That is: /usr/local/bin/cinnamon-lockscreen-background.sh for which file to autostart.
I quoted it last month.

Hope I doesn't guess wrong what you asked.

[Jerboum]

I was asking to you about how to call this new created file in "Autostart" anyway I called it x.desktop and it worked

[OK, I begin to wonder if what they call "screensaver animation" is not just a feature that darken the display after a while (?)]

> I guess now it is the clock's display that is moving on screen step by step, randomly

It appears that this script stopped to work without explanations
What is weird is that it works several days, and this morning I noticed it was down.

[after a while]
In fact it works but inconsistently
This morning I began to test it and it didn't work.
That's Linux

[AndyMH]

I see the background darkened when I lock the system, why is that a problem?

[Jerboum]

because I don't want it to be visible (as the title tells)

[PaulL]

because I don't want it to be visible (as the title tells)

If you don't want people to see that the computer is on, wouldn't turning off the monitor be a solution? If your monitor has an indicator light, it will show, even if the screen is black. Alternatively, if you don't mind the power light showing, a black desktop background will achieve what you want, since the Screensaver/Lock screen is simply a darkened version of the wallpaper. Surely this would be acceptable, since you are using the computer only to run your security cameras, right?

[Jerboum]

If you don't want people to see that the computer is on, wouldn't turning off the monitor be a solution? If your monitor has an indicator light, it will show, even if the screen is black. Alternatively, if you don't mind the power light showing, a black desktop background will achieve what you want, since the Screensaver/Lock screen is simply a darkened version of the wallpaper. Surely this would be acceptable, since you are using the computer only to run your security cameras, right?

Not really because anyway a person that is only curious, can turn on the monitor, though it is not so simple because there is no indicator light on it (Samsung Syncmaster B2430) and the symbol is almost invisible (deleted) but I think some persons can be used to light turn this kind of monitors on.
I turn it off but I can sometimes forget to do so

[cfb]

In LM21.3 Xfce there is a setting that will determine if a user background or a default background is shown when the session is locked.
A similar setting may be available in Cinnamon.

In Xfce the setting is found in the menu item named "Login Window" and the setting is called "Draw user backgrounds".
By default it is enabled and will show the current user background when the session is locked. If disabled a default background is shown.

[billyswong]

If you don't want people to see that the computer is on, wouldn't turning off the monitor be a solution? If your monitor has an indicator light, it will show, even if the screen is black. Alternatively, if you don't mind the power light showing, a black desktop background will achieve what you want, since the Screensaver/Lock screen is simply a darkened version of the wallpaper. Surely this would be acceptable, since you are using the computer only to run your security cameras, right?

Not really because anyway a person that is only curious, can turn on the monitor, though it is not so simple because there is no indicator light on it (Samsung Syncmaster B2430) and the symbol is almost invisible (deleted) but I think some persons can be used to light turn this kind of monitors on.
I turn it off but I can sometimes forget to do so

If your concern is about computer monitor shining to everyone telling others it is on but doesn't mind if someone come to your seat, wave your mouse and see the wallpaper, then we should go with a totally different approach. Telling the monitor to sleep immediately or sleep faster is better than mangling with wallpaper in lock screen time. An LCD monitor in power saving mode looks slightly different from it being instructed to show a black screen. There is the backlight emission.

[Jerboum]

In LM21.3 Xfce there is a setting that will determine if a user background or a default background is shown when the session is locked.
A similar setting may be available in Cinnamon.

In Xfce the setting is found in the menu item named "Login Window" and the setting is called "Draw user backgrounds".
By default it is enabled and will show the current user background when the session is locked. If disabled a default background is shown.

YESS !! that's it

Then I disabled this as soon