Lock screen without blank in 18.04

Question

I'm running Ubuntu 18.04 on a laptop. When I lock the computer, I want the screen to remain on indefinitely. I do want the computer to lock automatically when it is idle (but still, the screen should remain on).

First I tried in Settings -> Power to set Blank Screen to never, but that did not work. I have tried the suggestions from others who asked the same question here, but they are for different versions of Ubuntu and none of them worked for me.

Does anyone know how to fix this problem in 18.04?

Solution 1

I was looking for a way around this, and I think I've finally got it!

Gnome Extension

I looked through the bug that was referenced here to find the link to that extension.

Solution 2

When you lock your screen manually with Super + L just hold it a bit longer, then the screen will not blank immediately. It blanks after the time interval you set at Settings > Power > Blank Screen.

Edit: I tested it once again (this time it was chaging) and the screen did not blank when I locked my PC this way. It did not blank even after a few hours of idle time. So it probably only blanks when running on battery.

Solution 3

Check the current setting using:

gsettings get org.gnome.desktop.screensaver idle-activation-enabled

If the result is true turn it off using:

gsettings set org.gnome.desktop.screensaver idle-activation-enabled false

Second option to try is:

gsettings set org.gnome.settings-daemon.plugins.power idle-dim false

Gnome bug

There is a four year old Gnome bug addressing the issue of screen blanking immediately after lock here.

Comments

[MTV DNA]

Thanks for your answer. I tried it, but unfortunately this does not work. Immediately after I lock my pc the screen goes blank.

[WinEunuuchs2Unix]

Which desktop are you using in 18.04? Gnome, Unity, etc.

[MTV DNA]

I am using the default desktop (Gnome 3.28.1).

[WinEunuuchs2Unix]

I'm using Unity. I'll try to remember to test 18.04 gnome this weekend.

[MTV DNA]

I looked at the bug you posted, but I have nu idea what to do with the patches posted there. Anyways, the solution posted above works for me. Thanks for your help regardless!

[WinEunuuchs2Unix]

Glad its working!

[MTV DNA]

This works perfectly for me. I find it easier than the other solution, because sometimes if you hold the key too long you will go to the login screen, and you need to log in and lock the screen again. This is much easier, so I accepted it as the answer. Thanks!

[fquinner]

In my machine for some reason this only happened when locking with Super+L - it didn't happen when I locked the screen via the session menu.

[a113nw]

long hold Super + L worked on desktop as well.

[jII]

Any idea why this method works? Does holding Super+L longer have the same effect of pressing Super+L followed by another key, such as Enter?

[Dan Dascalescu]

@4myle: still works in Ubuntu 20, and it's great for monitors that don't resume properly from standby.

[Herohtar]

@jII I'm fairly certain this is only working because it's causing the keystroke to be repeated, which instantly cancels the blanking. You should be able to achieve the same effect by pressing any other key or moving the mouse immediately after locking the screen. If you have screen blanking disabled in the power settings it won't blank again. The answer from James is the actual solution for disabling it.